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As a new President of the United States is elected, the NASA administrator role is usually reviewed. With the election of Trump, a new administrator has been chosen, Jared Isaacman. He is a billionaire entrepreneur, an experienced jet pilot and has himself completed to private flights to space. He was also the first to complete a spacewalk during the Polaris Dawn mission. Isaacman replaces the outgoing administrator Bill Nelson, a former space shuttle astronaut and senator. 

Jared Isaacman was born on 11 February 1983. At 41, he is probably most well known for commanding the Inspiration 4 mission, the first all civilian spaceflight. He is also well known for initiating the Polaris Program to push forward private space exploration. It was during the Polaris Dawn mission that Isaacman became the first private astronaut to successfully undertake a spacewalk. As a skilled pilot he holds a number of aviation records including having circumnavigated the world in a light jet.

The Polaris Dawn crew (left to right): Anna Menon, Scott Poteet, Jared Isaacman, and Sarah Gillis. Credit: Polaris Program/John Kraus

His wealth of experience that means Isaacman is well placed to drive NASA forward as it continues partnering with private companies like SpaceX. President-elect Donald Trump has nominated Isaacman to serve as NASA’s administrator and, if confirmed, will be the first person to run the agency that has experience in command of a space mission. 

Previously Isaacman founded the Shift4 Payment financial technology company. He launched the company at the age of 16 and led the organisation into a multibillion dollar success. Clearly having aptitude in the technology sector, Isaacman soon showed his ability manage large organisations, something he can take to his new role managing NASA’s wide ranging portfolio. 

Like all who take on the administrator role, Isaacman has a vision for NASA. He is keen to drive forward public-private collaboration and global partnerships as a cornerstone to NASA’s mission. Pledging to ensure NASA remains at the forefront of technological development and discovery. The nomination comes at a key point for NASA as the Artemis mission ramps up toward its Moon landings. 

Artist’s rendering of the Starship HLS on the Moon’s surface. NASA has contracted with SpaceX to provide the lunar landing system. Credit: SpaceX

As part of the announcement on TruthSocial.Com, Trump said “Jared’s passion for space, his astronaut experience, dedication to pushing the boundaries of exploration, unlocking the mysteries of the universe and advancing the new space economy, make him ideally suited to lead NASA into a bold new era.“

Even though President-elect Trump has nominated Isaacman, his appointment has to be confirmed by the Senate. If successful he will lead NASA’s 18,000 employees and $25 billion budget! Certainly not a job for the faint hearted. 

Source : Jared Isaacman’s X Feed

The post Jared Isaacman is Trump’s Choice for NASA Administrator appeared first on Universe Today.

The Artemis moon landings are delayed again due to technical difficulties. This time, the problem is with the Orion spacecraft heat shield. NASA administrator Bill Nelson announced that the new landing dates are in April of 2026 for Artemis II and sometime in 2027 for the first human landing during the Artemis III mission.

The difficulties the Artemis program faces stem from the complexity of the hardware and trajectories needed to take astronauts to the Moon according to Nelson. “The Artemis campaign is the most daring, technically challenging, collaborative, international endeavor humanity has ever set out to do,” said Nelson. He pointed out that the mission has made a lot of progress. However, there’s more work to be done, in particular on the Orion life support systems. Artemis II is next up in early 2026. It will be a test flight to demonstrate the viability of all the systems, said Nelson. “We need to get this next test flight right. That’s how the Artemis campaign succeeds.”

Making a safe return through Earth’s atmosphere is a vital part of the mission. After Orion came back from its Artemis 1 mission in November 2022, engineers noticed issues with the heat shield. They figured out that gases generated inside the heat shield didn’t vent properly. That caused cracks in the shield and triggered an investigation. The decision to delay the Artemis II test flight came after that investigation. This allows NASA engineers to work with the heat shield currently attached to the Orion capsule for the April 2026 flight. In addition, they’re studying the re-entry process to avoid future problems with the shield.

Artemis II to the Moon

As we all know, the Artemis program will allow long-term exploration of the Moon. The April 2026 mission is a test flight that will orbit, but not land, and then return to Earth. The idea is to test all the spacecraft’s systems with astronauts on board.

The Orion spacecraft is the crew’s living quarters and lab, all in one. It’s built to carry four astronauts from Earth to space and ultimately to the Moon. It makes sense that this “home away from home” has to be shielded from pretty much anything that space—and Earth’s atmosphere—can throw at the capsule. This includes the ultrahot trip through our atmosphere on the return trip. At times, Orion experiences temperatures up to 2700 C (5000 F), which could harm the capsule if not for the shielding. So, the shield is a life-saver.

The heat shield retrieved after the Artemis 1 test flight to the Moon. Crews inspected it to understand what caused it to char. Courtesy: NASA.

When Orion first encountered the heat shield problem, engineers determined that heating rates increased during the spaceship’s planned “dips” into the atmosphere. It was performing a skip guidance entry technique. Heat built up inside the heat shield’s material and gases accumulated. Eventually, that cracked areas in the outer layer of the shield and blew some of it off to space. It turns out that if astronauts had been aboard, they would not have been affected. However, now that engineers understand what occurred, they can enhance the heat shield material to make sure it doesn’t happen again. In addition, the mission plan will be altered to change how far the capsule flies between atmospheric re-entry and eventual landing.

Upgrading Mission Plans

The extended time until the April 2026 and mid-2027 Artemis missions will allow improvements to the capsule and launch systems. For example, engineers can give more attention to environmental and life support systems. This is particularly important for the Artemis III mission. It will launch on top of a Space Launch System rocket into Earth orbit. Once there, the mission will perform a translunar injection to send it to lunar space.

Not only will it carry astronauts to the Moon, but they will land in the south polar region using a SpaceX landing system. That 30-day mission will require at least two crew members to spend a week at the pole collecting samples, doing site photography, and measuring conditions there.

This image shows nine candidate landing regions for NASA’s Artemis III mission, with each region containing multiple potential sites for the first crewed landing on the Moon in more than 50 years. The background image of the lunar South Pole terrain within the nine regions is a mosaic of LRO (Lunar Reconnaissance Orbiter) WAC (Wide Angle Camera) images. Credit: NASA

Artemis III will be the first time anyone has set foot on the Moon since the last Apollo mission in December 1972. The entire Artemis program aims at providing long-term habitation and study of Earth’s nearest neighbor in space. To that end, NASA has been studying several interesting landing spots at the pole.

Eventually, there will be an orbiting lunar station, plus habitats on the surface and regular trips between. NASA and other agencies expect that lunar explorers will be spending their time studying the surface and geology of the Moon, plus determining what resources are available for long-term exploration and habitation. However, given the pace of the program, those next developments probably won’t take place until the 2030s.

For More Information

NASA Identifies Cause of Artemis I Orion Heat Shield Chart Loss
As Artemis Moves Forward, NASA Picks SpaceX to Land Next Americans on Moon
Artemis II
Artemis III: NASA’s First Human Mission to the Lunar South Pole

The post NASA Pushes Human Moon Landing Back to 2027 appeared first on Universe Today.

Sometimes in science you have to step back and take another look at underlying assumptions. Sometimes its necessary when progress stalls. One of the foundational questions of our day concerns the Fermi Paradox, the contradiction between what seems to be a high probability of extraterrestrial life and the total lack of evidence that it exists.

What assumptions underlie the paradox?

The Fermi Paradox is based on the fact that our galaxy is home to hundreds of billions of stars, with many or even most of them likely hosting multiple planets. The sheer number of planets urges us to conclude that life should be abundant, and that some of this life must have evolved into sentiency like us. Even if only a small percentage become technological space-faring civilizations, there should still be many of them. The paradoxical part is that if this is true, there should be evidence. We should see some indication that they’re out there, or they should’ve even contacted us by now. But we don’t.

There are many proposed solutions to the paradox. The primary one is that life is not abundant and technological civilizations are exceedingly rare. We could be the only one. There’s also the Great Filter solution, which states that some critical step to becoming a spacefaring civilization that spreads throughout the galaxy is unattainable. A natural catastrophe of some sort, our own stupidity and war, the inevitability of an AI singularity taking out a civilization; many solutions to the paradox have been proposed, but we’re left wondering.

Another concept related to the Fermi paradox is the Kardashev Scale. It measures the technological advancements of species from Type 1 to Type 3. A Type 1 civilization can harness all of the energy available on a planet, while a Type 2 civilization can do the same for an entire star. A type 3 civilization on the Kardashev Scale has advanced so far that they can capture all of the energy emitted by an entire galaxy. It’s a framework for thinking about civilizations on extraordinarily long timescales.

Energy consumption is estimated in three types of civilizations defined by the Kardashev scale. Credit: Wikimedia Commons

There’s an underlying assumption to all of this thinking, and in a new research article, researcher Lukáš Likavčan examines them. Likavčan is a researcher at the Center for AI and Culture, NYU Shanghai, and at the Berggruen Institute. The research is titled “The Grass of the Universe: Rethinking Technosphere, Planetary History, and Sustainability with Fermi Paradox.”

The concept of environmental humanities is part of the background in Likavčan’s research. Environmental humanities is an interdisciplinary field in academics that examines the relationships between humans and environment. It combines environmental studies with humanities like history and literature. It criticizes our anthropocentric views of nature and tries to understand how we think about nature, how we represent it, and how we impact ecosystems.

“SETI is not a usual point of departure for environmental humanities,” Likavčan writes. “However, this paper argues that theories originating in this field have direct implications for how we think about viable inhabitation of the Earth. To demonstrate SETI’s impact on environmental humanities, this paper introduces the Fermi paradox as a speculative tool to probe possible trajectories of planetary history, and especially the “Sustainability Solution” proposed by Jacob Haqq-Misra and Seth Baum.”

Likavčan is referring to the paper “THE SUSTAINABILITY SOLUTION TO THE FERMI PARADOX,” in which researchers Jacob Haqq-Misra and Seth Baum presented an overlooked solution to the paradox. Their sustainability solution states that we don’t see any evidence of ETIs because rapid growth is not a sustainable development pattern. From this perspective, the Kardashev Scale is rendered futile. No civilization will ever use all available energy from its planet, star, or galaxy, because the growth required to reach that level of mastery is unsustainable.

Extraterrestrials in the 1979 movie “Close Encounters of the Third Kind.” Are there other technological civilizations out there? What are they like? Do they really expand throughout space? Credit: Columbia Pictures / Alien Wiki

“By positing that exponential growth is not a sustainable development pattern, this solution rules out space-faring civilizations colonizing solar systems or galaxies,” Likavčan writes in regards to the sustainability solution. He elaborates on the solution by re-thinking three underlying concepts: technospheres, planetary history, and sustainability.

Likavčan says that the technosphere is only a transitory layer. It won’t continue to grow until every civilization builds a Dyson sphere around their star to become a Type 2 civ on the Kardashev Scale. That’s simply not sustainable. We’re biased towards that thinking because from our perspective, we’re expanding into space and the future seems bright and almost unlimited. Behind us are centuries of colonial expansions and decades of stunningly rapid technological progress, so it’s almost automatic to think it can continue. But alarm bells are ringing. Continual technological progress may very well be unsustainable.

“As the authors state,” Likavčan writes regarding Haqq-Misra and Baum’s sustainability solution, “the formulation of the Fermi paradox contains a biased presupposition based on the observation of only one planetary community of intelligent species (i.e. humans), which is in turn based on a warped understanding of human history, which assumes that history unfolds in a progressive series of civilizational, colonial expansions.”

A Type II civilization is one that can directly harvest the energy of its star using a Dyson Sphere or something similar. Credit: Fraser Cain (with Midjourney)

In this case, our efforts to detect other civilizations through their technology is unlikely to be successful. “The technosphere is a transitory layer that shall fold back into the biosphere,” Likavčan writes.

We need to rethink our assumptions about our planetary history, too, according to Likavčan. We assume that what has played out on Earth is “normal” and widespread. The human community on our planet is not a single occurrence. Instead, it plays out everywhere that life evolves on a suitable planet in the right location around a suitable star.

Here Likavčan points to the sci-fi author Stanislaw Lem. In his novel Solaris, one of Lem’s characters says, “Us, we’re common, we’re the grass of the universe, and we take pride in our commonness, that it’s so widespread, and we thought it could encompass everything.” This is the “grass of the Universe” metaphor.

“The metaphor of the “grass of the universe” is central to this paper, as it recognizes the crucial environmental implication of the potential existence of intelligent life elsewhere in the universe—namely that the history of the human planetary community on Earth is not a singular occurrence, but potentially unfolds throughout the cosmos in many permutations, conditioned by the setting of given star system and the inhabited exoplanet(s),” Likavčan writes.  

We don’t how true this may or may not be, but we can recognize it as an assumption and open our thinking to other possibilities.

The sustainability solution to the Fermi paradox outlined by Haqq-Misra and Baum says that “… human civilization needs to transition to sustainable development in order to avoid collapse.” There seems to be some inherent wisdom in that statement. It may even be axiomatic. But for Likavčan it may not be enough.

Here we encounter the concept of genesity, introduced in a 2022 paper. It goes beyond our notions of habitability, which largely rely on the presence of water, with energy from a star, and including the CHNOPS elements (carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur), deemed critical for life. “Finally, in an effort to be more inclusive of life as we do not know it, we propose tentative criteria for a more general and expansive characterization of habitability that we call genesity,” the authors of the 2022 paper wrote. Genesity is basically life as we do no know it.

This all adds up to a different understanding of advanced civilizations that can somehow survive, including our own if humanity is fortunate. The planet is primary, and any technosphere will have to be harmonious with planetary conditions.

“In this light, the Sustainability Solution to the Fermi Paradox contains a philosophical takeaway: it tells a story of the convergence of the technosphere with the planet’s pre-existing conditions, rather than the story of replacement or dominance,” Likavčan writes.

Instead of humans being primary, or even existing life being primary, it’s planets that are primary. So a technosphere is only sustainable when it expands or strengthens a planet’s genesity. That puts efforts like SETI, and our understanding of our own civilization’s trajectory, in a new light.

“Since the planets assume the central role in this normative framework, this paper proposes to follow innovative moral philosophies, such as planetocentric ethics,” Likavčan explains.

From that perspective, the only successful technosphere is one that folds back into the biosphere, making it very difficult, even impossible, to detect. Does that means it’s time to shut down SETI and any similar future endeavours? Of course not.

It’s about rethinking our underlying assumptions. To do that, Likavčan proposes some avenues for further research.

Antennas of the Very Large Array against the Milky Way. Even with all we’ve learned, we’re still left wondering about many things. Credit: NRAO/AUI/NSF/Jeff Hellerman

We need a better understanding of how technospheres might fold back into biospheres. Not just in our case, but from a wider perspective. We also need to do more work into planetary histories and try to ascertain what parts of ours might be more generic and what parts might not reflect other planets with biospheres at all. Lastly, we still don’t know what life as we don’t know it might look like. Will evolution always produce “endless forms most beautiful and most wonderful,” as Darwin said.

Our predicament is that we have so little information to go on. Naturally, we look around us and use our circumstances here on Earth as a springboard.

However, as we go about our business, it’s important to sometimes examine our underlying assumptions, as this paper shows.

The post Advanced Civilizations Could be Indistinguishable from Nature appeared first on Universe Today.

For the past thirty years, NASA’s Great Observatories – the Hubble, Spitzer, Compton, and Chandra space telescopes – have revealed some amazing things about the Universe. In addition to some of the deepest views of the Universe provided by the Hubble Deep Fields campaign, these telescopes have provided insight into the unseen parts of the cosmos – i.e., in the infrared, gamma-ray, and ultraviolet spectrums. With the success of these observatories and the James Webb Space Telescope (JWST), NASA is contemplating future missions that would reveal even more of the “unseen Universe.”

This includes the UltraViolet Explorer (UVEX), a space telescope NASA plans to launch in 2030 as its next Astrophysics Medium-Class Explorer mission. In a recent study, a team led by researchers from the University of Michigan proposed another concept known as the Mission to Analyze the UltraViolet universE (MAUVE). This telescope and its sophisticated instruments were conceived during the inaugural NASA Astrophysics Mission Design School. According to the team’s paper, this mission would hypothetically be ready for launch by 2031.

The study was led by Mayura Balakrishnan, a graduate student from the Department of Astronomy at the University of Michigan. She was joined by researchers from the Laboratory for Atmospheric and Space Physics (LASP), the Institute for Gravitation and the Cosmos (IGC), the Center for Cosmology and AstroParticle Physics (CCAPP), the Kavli Institute for Astrophysics and Space Research, the European Space Agency (ESA), the Space Telescope Science Institute (STScI), NASA’s Goddard Space Flight Center, NASA’s Jet Propulsion Laboratory and multiple universities. The paper that details their findings appeared in the Astronomical Society of the Pacific.

NASA’s Solar Dynamics Observatory captured these images of the solar flares in the extreme ultraviolet wavelength. Credit: NASA/SDO

In the past fifty years, ultraviolet observatories have revolutionized our understanding of the Universe. However, observations of astrophysical phenomena in the ultraviolet (UV) wavelengths can only be performed at high altitudes or in space due to interference from Earth’s atmosphere – which is very efficient at absorbing UV radiation. As study co-author Dr. Emily Rickman, an ESA astronomer and Science Operations Scientist at the STScI, told Universe Today via email:

“UV astronomy provides us insight into highly energetic events that cannot be captured at other longer wavelengths, like in the visible or infrared wavelength regime, that have a much larger pool of facilities available. Through observing in the UV, our understanding of the Universe has made significant advancement through studying star formation, galaxy formation, as well as highly energetic events on planets both within our Solar System and in exoplanetary stellar systems.

“Some of the notable areas of this understanding have been in capturing UV radiation from stellar winds emitted from young high-mass stars, which help us piece together how such massive stars formed in the early Universe. On the planetary side, UV astronomy has allowed us to observe active aurorae on Jupiter’s poles and how these are influenced by solar storms on the Sun. These active aurorae on Jupiter were unexpected and opened up a whole new understanding of planets, their atmospheres, and how they interact within their environment.”

The first UV satellite, the Orbiting Astronomical Observatory 2 (OAO 2) launched in 1968, shortly before the highly anticipated launch of Apollo 8 (the first crewed mission to the Moon). Among its many accomplishments, OAO 2 enabled the early characterization of the absorption of electromagnetic radiation by interstellar gas and dust (aka. interstellar extinction). This was followed by the Extreme Ultraviolet Explorer (EUVE), which launched in 1992 and conducted the first all-sky survey of far-UV sources.

Artist’s impression of the Neil Gehrels Swift Observatory. Credit: NASA

Then came the Far Ultraviolet Spectroscopic Explorer (FUSE) in 1999, which conducted the first systemic investigations of the intergalactic medium (IGM). Then there was the Galaxy Evolution Explorer (GALEX), which operated from 2003 to 2013 and has conducted the deepest all-sky UV survey to date. There’s also the Ultraviolet and Optical Telescope on the Neil Gehrels Swift Observatory and the three UV instruments on the Hubble Space Telescope – the Space Telescope Imaging Spectrograph (STIS), the Wide Field Camera 3 (WFC3), and the Cosmic Origins Spectrograph.

Unfortunately, none of these detectors can study the cosmos in the far- and extreme-ultraviolet wavelengths with the detail of a PI-led mission. As Rickman noted, this and other factors have limited UV astronomy so far:

“One of the biggest limitations really comes from the dearth of facilities capable of observing within the UV wavelength range. Because UV observatories have the requirement of being in space due to the Earth’s atmosphere blocking out most of the UV radiation, these space-based UV observatories are much more expensive to build and operate than ground-based observatories.

“Due to the limited number of UV observatories, the ones that are currently active, like the Hubble Space Telescope, are over-subscribed by astronomers all over the world, indicating the need and importance for such observatories to exist. In addition, the far extreme UV wavelength is not currently captured with existing instrumentation, providing a blind spot to some astronomical phenomena to be studied.”

While the proposed Habitable World Observatory (HWO) is expected to have advanced UV capabilities, this mission is still in the early stages of planning and is not expected to launch until the 2040s. To this end, the team proposed a UV space telescope concept called the Mission to Analyze the UltraViolet
universE (MAUVE), a wide-field spectrometer and imager conceived during the inaugural NASA Astrophysics Mission Design School (AMDS) hosted by the JPL in response to the 2023 Announcement of Opportunity. As Rickman explained:

“The MAUVE mission concept focuses on three main themes within the context of the Astronomy and Astrophysics 2020 Decadal Survey. Those themes are ‘Are We Alone?/Worlds and Suns in Context,’ ‘How Does the Universe Work?/New Messengers and New Physics,’ and ‘How Did We Get Here?/Cosmic Ecosystem.’ Within the context of answering the question ‘Are we alone?’, MAUVE seeks to study the atmospheric escape of sub-Neptunes, which is hypothesized to be due to either photoevaporation or core-powered mass loss. This will help us understand the habitability of extrasolar systems’ environments, as well as the formation and evolution of exoplanets and their atmospheres.”

“In addition, MAUVE would study the atmospheric composition of hot gas on giant exoplanets and whether they are influenced by equilibrium or disequilibrium condensation, which is vital in order for us to understand exoplanetary atmospheres, giving rise to clues of where life could exist in the Universe. For understanding ‘How does the Universe work?’”

“MAUVE would study whether blue kilonovae are driven by radioactive cooling or rapid shock cooling, which is fundamental in understanding explosive phenomena in the Universe, as well as studying whether type 1A supernovae arise from a white dwarf accreting material from a stellar companion, or from merging white dwarfs. And in order to study ‘How did we get here?’, MAUVE would look at if diffuse extragalactic emission results from faint galaxy cluster members and rogue stars, or from shocks of cluster mergers.”

Conceptual vision of the Habitable Worlds Observatory. Credit/©: NASA’s Goddard Space Flight Center Conceptual Image Lab

These general themes, said Rickman, are key unanswered questions that astronomers are very interested in addressing as they underpin our understanding of the Universe. By extending the wavelength range of existing UV observatories, MAUVE would be able to study the kinds of high-energy cosmological events that could answer some of these questions. In addition, said Rickman, MAUVE would be allocated a substantial amount (70%) of General Observer (GO) time:

“[This would allow] the wider community to propose their observing ideas that could be studied in this largely unexplored parameter space, answering fundamental questions like ‘How do star-forming structures arise and interact with the diffuse interstellar medium?’, ‘What are the most extreme stars and stellar populations?’,  ‘How do habitable environments arise and evolve within the context of their planetary systems?’. The possibility to study these questions would provide a fundamental insight into some of the building blocks of our understanding of the Universe.”

Further Reading: arXiv

The post MAUVE: An Ultraviolet Astrophysics Probe Mission Concept appeared first on Universe Today.

Our understanding of the Universe is profound. Only a century ago, astronomers held a Great Debate to argue over whether our galaxy was an island universe, or whether nebulae such as Andromeda were galaxies in a much larger cosmos. Now we know that the Universe is billions of years old, ever expanding to billions of light-years across, and filled with not just stars and galaxies but with dark energy and cold dark matter. Astronomers summarize this understanding as the LCDM model, which is the standard model of cosmology. While the observational data we have strongly supports this model, it is not without its challenges.

The most striking challenge is known as the Hubble tension. When we measure the rate of cosmic expansion in various ways, we can calculate what is known as the Hubble constant or Hubble parameter, which defines the rate of cosmic expansion. This rate also tells us things such as the age of the Universe and the average density of dark energy and matter. While the various observations generally cluster around 68-69 km/s/Mpc, several of the methods give results outside that range. There is some evidence to support the idea that the current rate of cosmic expansion is greater than that during the early Universe, which is known as cosmic shear tension. All of this means either some of our methods are in error somehow or there is a fundamental aspect of cosmic expansion we don’t yet understand.

Related to this are the mysteries surrounding dark energy. Within the standard model, dark energy is a property of space and time and is universal throughout the cosmos. But there is an alternative view that holds dark energy is an independent scalar field within spacetime, sometimes referred to as quintessence. Observations such as the clustering scale of galaxies generally support the former model, but there are a few studies here and there that suggest the latter. We don’t yet have enough data to rule out either completely.

Observations of the Hubble parameter. Credit: N. Palanque-Delabrouille

Then, of course, there is the great bugbear of dark matter. Observations strongly support its existence, and that dark matter makes up most of the matter in the Universe. But within the standard model of particle physics, there is nothing that could comprise dark matter, and countless experiments trying to detect dark matter directly have so far yielded nothing. Alternative models such as modified gravity can account for some of our observations, but models must be tweaked just so to fit data, and no alternative approach agrees with all our observations. Dark matter remains central to the standard cosmological model, but its true nature remains in shadow.

In short, we are tantalizingly close to a complete and unifying model of the Universe, but there are deep and subtle mysteries we have yet to solve. We need more theoretical ideas, and we desperately need more observational data. Fortunately, there are exciting projects in the pipeline that could solve these mysteries in the near future.

One of these is the Dark Energy Spectroscopic Instrument (DESI) survey, which is currently underway. Over the course of the five-year project, DESI will observe the spectra of more than 35 million distant galaxies, giving us a detailed 3D map of the Universe. In comparison, the Sloan Digital Sky Survey (SDSS) gathered data on 4 million galaxies and gave us the most detailed view of galactic clustering at the time. With DESI, we will be able to see the interaction between dark matter and dark energy across billions of years and hopefully determine whether dark energy is constant or changes over time.

Comparison of SDSS (left) with DESI (right). Credit: David J. Schlegel

Another useful tool will be the Vera Rubin observatory, which should come online in a few months. By giving us a high-resolution map of the sky every few days, Rubin will allow us to study transient phenomena such as supernovae used to measure cosmic expansion. It will also give us a rich view of matter within our galaxy and could reveal aspects of how that matter interacts with dark matter.

Further into the future, there are planned projects such as the Wide-field Spectroscopic Telescope (WST), which will expand on the abilities of Rubin observatory, and the Spec-S5, which will complement the DESI surveys. Both of these are still in the planning stage, but could become the DESI surveys. Both of these are still in the planning stage but could become operational within a decade or so.

In the 1920s, the Great Debate of Astronomy was solved thanks to a wealth of data. The rise of photographic astronomy allowed us to see the Universe in transformative new ways and made modern cosmology possible. We are now entering an era of large data astronomy, where wide-field telescopes and large surveys will provide more data in an evening than could be gathered in a year just decades ago. Brace yourselves for another revolutionary era of astronomy.

Reference: Palanque-Delabrouille, N. “Future directions in cosmology.” arXiv preprint arXiv:2411.03597 (2024).

The post Cosmology is at a Crossroads, But New Instruments are Coming to Help appeared first on Universe Today.

One of the great things about CubeSat designs is that they constrain the engineers who design them. Constraints are a great way to develop novel solutions to problems that might otherwise be ignored without them. As CubeSats become increasingly popular, more and more researchers are looking at how to get them to do more with less. A paper from 2020 contributes to that by designing a 3U CubeSat mission that weighs less than 4 kilograms to perform a fly-by of a Near Earth Asteroid (NEA) using entirely off-the-shelf parts.

The research, carried out by a team based at the Delft University of Technology, had several mission requirements they were trying to meet. Some were standard like it had to have a propulsion system and a way to get data back to Earth. However, some were more challenging – it had to weigh less than 4 kg, it had to fit into a 3U CubeSat body (which measures (100mm x 100mm x 340.5mm), it had to perform its mission in less than 650 days, and, perhaps the most technically challenging goal – it has to “exploit a fully-autonomous navigation strategy.”

First, let’s look at the mission design. Since there are around 35,000 known NEAs, mission designers would be spoiled for choice. However, getting to one with a relatively limited propulsion budget (since propellant increases the weight – one of the design constraint limits) and finding the right one would require extensive searching of the JPL Small-Body Database. 

Fraser discusses how we find NEAs

Once an NEA has been selected, the mission designers could plan the optimal trajectory. However, to meet the requirement of an autonomous navigation strategy, the CubeSat itself will have to find its way to the asteroid and enact any course corrections along the way. This could be extremely difficult, given the low brightness of many of the target asteroids and how that brightness might change based on what side of it is facing the Sun and what angle the CubeSat is approaching it from. The scientific payload, including a visible light and IR camera, would have to work in tandem with a micro star tracker to ensure the trajectory is optimal for scientific data collection.

That data collection might only last a few minutes, as the limited propellant for the mission would require it to be a fly-by rather than an orbit. The resulting image might be as small as a 6 x 6 pixel image for a 300m diameter asteroid. This would provide orders of magnitude with more resolution than ground-based observations for most. Still, it would not be enough to get into the details of mass and composition that planetary protectors and asteroid mining enthusiasts alike would most desire.

Any new information is better than no information, though, and the simplicity of the design for this mission’s hardware makes it relatively inexpensive and, therefore, mass-producible. It consists of six major sub-systems – the “payload,” which is essentially a visible light and infrared camera; the propulsion system, which is a microjet ion propulsion engine; the attitude determination and control system (ADCS), which helps navigate; a communication system that uses an X-band antenna to communicate back to the Deep Space Network infrastructure, and a power system that would involve deployable solar panels. 

Some of the engineering that goes into CubeSats is pretty impressive, as this JPL video shows.
Credit – NASA Jet Propulsion Laboratory YouTube Channel

Overall, the mission met the goal of fitting entirely into a 3U package and came in at 3.8kg using off-the-shelf components. However, thermal management systems and radiation shielding were not considered in the design. Other challenges, like getting time on the already overstretched Deep Space Network ground antennas, are left for another paper.

But if nothing else, this paper proves that it is possible, on paper at least, to design an inexpensive mission to collect data on an asteroid and that that mission can be replicated hundreds or even thousands of times at relatively low cost. As CubeSats gain more and more capabilities and more and more traction, and as launch costs get lower and lower, it’s becoming increasingly plausible that someday, a system like this might very well make its way past an asteroid and send data back that we otherwise wouldn’t have gotten.

Learn More:
Casini et al – Novel 3U Stand-Alone CubeSat Architecture for Autonomous Near Earth Asteroid Fly-By
UT – A Pair of CubeSats Using Ground Penetrating Radar Could Map The Interior of Near Earth Asteroids
UT – A Mission To Find 10 Million Near Earth Asteroids Every Year
UT – Swarms of Orbiting Sensors Could Map An Asteroid’s Surface

Lead Image:
ESA’s Hera Mission is joined by two triple-unit CubeSats to observe the impact of the NASA-led Demonstration of Autonomous Rendezvous Technology (DART) probe with the secondary Didymos asteroid, planned for late 2022.
Credit: ESA

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China’s growing presence in space has been undeniable since the turn of the century. Between sending the first “taikonaut” to space in 2003 (Yang Liwei), launching the first Chinese robotic mission to the Moon (Chang’e-1) in 2007, and the deployment of their Tiangong space station between 2021-2022, China has emerged as a major power in space. Accordingly, they have bold plans for the future, like the proposed expansion of their Tiangong space station and the creation of the International Lunar Research Station (ILRS) by 2035.

In their desire to become a space power that can rival NASA, China also has its sights on Mars. In addition to crewed missions that will culminate in a “permanent base,” they intend to conduct a sample-return mission in the near future. This will be performed by the Tianwen-3 mission, which is currently scheduled to launch in 2028 and return samples to Earth by 2031. In a recent article, the Tianwen-3 science team outlined their exploration strategy, including the methods used to retrieve the samples, the target locations, and how they’ll be analyzed for biosignatures that could indicate the presence of past life.

Zengqian Hou was the article’s lead author, a geologist with the Deep Space Exploration Laboratory (DSEL) and the Chinese Academy of Geological Sciences (CAGS), and the mission team supervisor. His fellow team members included the mission’s chief designer, Liu Jizhong, and colleagues from the DSEL, the Lunar Exploration and Space Engineering Center, the Chinese Academy of Sciences (CAS), and the University of Science and Technology of China (USTC). The article was recently published in the November edition of National Science Review.

This image was taken by a small camera jettisoned from China’s Tianwen-1 spacecraft to photograph the spacecraft in orbit above the Martian north pole. Credit: CNSA/PEC

This mission is the third in China’s Tianwen (Chinese for “questions to heaven”) exploration program. The previous mission (Tianwen-1) included an orbiter, a lander, and the Zhurong rover, which reached Mars in February 2021. The successful deployment of this mission made China the third nation (after the Soviet Union and the U.S.) to land on Mars. Highlights of the mission include the mapping of the entire Martian surface by the orbiter and the discovery of hydrated minerals by Zhurong, further confirming that Mars once had liquid water on its surface.

News of this latest mission was first shared by Jizhong at the 2nd International Deep Space Exploration Conference, which took place from September 4th to 7th in Huangshan City, China. However, few details were shared at the time, though a concurrently published paper suggested that the mission could include a helicopter similar to NASA’s Ingenuity. According to the latest from Jizhong, the Tianwen-3 will consist of two launches sometime in 2028 using the Long March 5 (CZ-5) rocket. While one CZ-5 will send the orbiter/return vehicle, the second will send the lander/ascent vehicle. As Liu told the state-owned news agency Xinhua:

“China has retrieved the first-ever samples from the far side of the moon with the Chang’e-6 mission this year. Since Mars is much farther away than the moon, it will take two launches to carry out the Mars sample-return mission due to the limited carrying capacities of our current rockets. Two Long March-5 carrier rockets will be used for the mission.”

Other details include the 86 potential landing sites proposed by the team, which are primarily concentrated in the ancient Chryse Planitia and Utopia Planitia regions. These areas are considered good places to search for potential biosignatures that could be preserved remains of ancient life. This includes features that indicate the presence of past water, including delta fans, lake beds, and the coastline, suggesting the presence of a past ocean in the Northern Lowlands. The team also stated that Tianwen-3 will carry payloads developed with international partners.

A wireless camera took this ‘group photo’ of China’s Tianwen-1 lander and rover on Mars’ surface. Credit: CNSA

They also stressed the necessity for new instruments specifically designed to detect biosignatures. To this end, they have developed a 13-phase mission plan that leverages in-situ and remote-sensing detection technologies. Liu also disclosed that the mission will rely on multi-point surface sampling, fixed-point in-depth drilling, and in-flight vehicle sampling to obtain diverse samples. They also state that China will conduct joint research with scientists worldwide on Mars samples and detection data.

What is clear from this latest news is that China intends to preempt NASA and the ESA’s proposed Mars Sample Return (MSR) mission. Due to budget cuts announced earlier this year, this mission is currently stuck in the design phase. Similarly, China has indicated that the Tianwen-4 mission will explore the Jupiter system to learn more about its moons and their evolutionary history. This mission is scheduled to launch in September 2029 and will follow on the heels of NASA’s Europa Clipper and the ESA’s JUpiter Icy Moons Explorer (JUICE).

This is in keeping with China’s pattern of following in NASA’s footsteps, catching up with them and surpassing them as the leader in space exploration. If they manage to return Martian samples to Earth before either NASA or the ESA, they will have accomplished a task no other space agency has. However, given the scientific value of these samples and the international cooperation that will go into their analysis will be to the benefit of all.

Further Reading: CGTN, Xinhua

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When Oumuamua traversed our Solar System in 2017 it was the first confirmed Interstellar Object (ISO) to do so. Then in 2019, Comet 2l/Borisov did the same thing. These are the only two confirmed ISOs to visit our Solar System. Many more ISOs must have visited in our Solar System’s long history, and many more will visit in the future. There are obviously more of these objects out there, and the upcoming Vera Rubin Observatory is expected to discover many more.

It’s possible that the Sun could capture an ISO or a rogue planet in the same way that some of the planets have captured moons.

It all comes down to phase space.

What would happen to our mature, sedate Solar System if it suddenly gained another member? That would depend on the object’s mass and the eventual orbit that it found itself in. It’s an interesting thought experiment; while Borisov and Oumuamua were smaller objects, a more massive rogue planet joining our Solar System could generate orbital chaos. It could potentially alter the course of life on Earth, though that is highly improbable.

How likely is this scenario? A new research note in Celestial Mechanics and Dynamical Astronomy outlines how our Solar System could capture an ISO. It’s titled “Permanent capture into the solar system,” and the authors are Edward Belbruno from the Department of Mathematical Sciences at Yeshiva University, and James Green, formerly of NASA and now from Space Science Endeavours.

Phase space is a mathematical representation that describes the state of a dynamical system like our Solar System. Phase space uses coordinates that represent both position and momentum. It’s like a multidimensional space that contains all of the possible orbital configurations around the Sun. Phase space captures the state of a dynamical system by tracking both position and momentum characteristics. Our Solar System’s phase space has capture points where an ISO can find itself gravitationally bound to the Sun.

Phase space is complex and is based on Hamiltonian mechanics. Things like orbital eccentricity, semi-major axis, and orbital inclination all feed into it. Phase space is best understood as a multidimensional landscape.

Our Solar System’s phase space includes two types of capture points: weak and permanent.

Weak capture points are regions in space where an object can be temporarily drawn into a semi-stable orbit. These points are often where the outer edges of objects’ gravitational boundaries meet. They’re more like gravitational nudges than an orbital adoption.

Permanent capture points are regions in space where an object can be permanently captured into a stable orbit. An object’s angular momentum and energy are an exact configuration that allows it to maintain an orbit. In planetary systems, these permanent capture points are stable orbital configurations that persist for extremely long periods of time.

Our Solar System’s phase space is extremely complex and involves many moving bodies and their changing coordinates. Subtle changes in phase space coordinates can allow objects to transition between permanent capture states and weak capture states. By the same token, subtle differences in ISOs or rogue planets can lead them into these points.

In their research note, the authors describe the permanent capture of an ISO this way: “The permanent capture of a small body, P, about the Sun, S, from interstellar space occurs when P can never escape back into interstellar space and remains captured within the Solar System for all future time, moving without collision with the Sun.” Purists will note that nothing can be the same for all future time, but the point stands.

Other researchers have delved into this scenario, but this work goes a step further. “In addition to being permanently captured, P is also weakly captured,” they write. It revolves around the notoriously difficult to solve three-body problem. Also unlike previous research, which uses Jupiter as the third body, this work uses the galaxy’s tidal force as the third body, along with the P and S. “This tidal force has an appreciable effect on the structure of the phase space for the velocity range and distance from the Sun we are considering,” they explain in their paper.

The paper focuses on the theoretical nature of phase space and ISO capture. It studies “the dynamical and topological properties of a special type of permanent capture, called permanent weak capture which occurs for infinite time.” An object in permanent weak capture will never escape, but will never reach a consistent stable orbit. It asymptotically approaches the capture set without colliding with the star.

There’s not much debate that rogue planets exist likely in large numbers. Stars form in groups that eventually disperse over a wider area. Since stars host planets, some of these planets will be dispersed through gravitational interactions prior to co-natal stars gaining some separation from one another.

“The final architecture of any solar system will be shaped by planet-planet scattering in addition to the stellar flybys of the adjacent forming star systems since close encounters can pull planets and small bodies out of the system creating what are called rogue planets,” the authors explain.

“When taken together, planet ejection from early planet-planet scattering and stellar encounters and in the subsequent evolution of a multi-planet solar system should be common and supports the evidence for a very large number of rogue planets that are free floating in interstellar space that perhaps exceed the number of stars,” the authors write, noting that that assertion is controversial.

So what does this all add up to?

The researchers developed a capture cross-section for the Solar System’s phase space then calculated how many rogue planets are in our Solar System’s vicinity. In our solar neighbourhood, which extends to a radius of six parsecs around the Sun, there are 131 stars and brown dwarfs. Astronomers know that at least several of them host planets, and all of them may very well host planets we haven’t detected yet.

Every million years, about two of our stellar neighbours come within a few light years of Earth. “However, six stars are expected to closely pass by in the next 50,000 years,” the authors write. The Oort Cloud’s outer boundary is about 1.5 light years away, so some of these stellar encounters could easily dislodge objects from the cloud and send them toward the inner Solar System. This has already happened many times, as the cloud is likely the source of long-period comets.

The familiar Solar System with its 8 planets occupies a tiny space inside a large spherical shell containing trillions of comets – the Oort Cloud. Gravitational perturbations dislodge comets from the cloud, sending some of them into the inner Solar System. Image Credit: Wikimedia Commons

The researchers identified openings in the Solar System’s phase space that could allow some of these objects, or ISOs or rogue planets, to reach permanent weak capture. They’re openings in the Sun’s Hill sphere, a region where the Sun’s gravity is the dominant gravitational force for capturing satellites. These openings are 3.81 light years away from the Sun in the direction of the galactic center or opposite to it.

“Permanent weak capture of interstellar objects into the Solar System is possible through these openings,” the authors state. “They would move chaotically within the Hill’s sphere to permanent capture about the Sun taking an arbitrarily long time by infinitely many cycles.” These objects would never collide with the Sun and could be captured permanently. “A rogue planet could perturb the orbits of the planets that may be possible to detect,” they conclude.

We’re still in the early days of understanding ISOs and rogue planets. We know they’re out there, but we don’t know how many or where they are. The Vera Rubin Observatory might open our eyes to this population of objects. It may even show how they cluster in some regions and avoid others.

According to this work, if they’re close to any of the openings in the Sun’s Hill sphere, we could have a visitor that decides to stay.

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The Universe is a turbulent place. Stars are exploding, neutron stars collide, and supermassive black holes are merging. All of these things and many more create gravitational waves. As a result, the cosmos is filled with a rippling sea of gravitational vibrations. While we have been able to directly detect gravitational waves since 2016, gravitational wave astronomy is still in its infancy. We have only been able to observe the gravitational ripples of colliding stellar black holes. Even then, all we can really detect is the final gravitational chirp created in the last moments of merging.

We can, however, gather indirect evidence of the cosmic background of gravitational waves. Last year, the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) released their first observations, which were based on millisecond pulsars.

The idea behind the NANOGrav project is that pulsars emit very regular radio pulses. Millisecond pulsars are just rapidly rotating neutron stars that happen to sweep a beam of radio energy in our direction with each rotation. So, unless a neutron star experiences a rare starquake, the pulsar timing is so consistent we can use it as a cosmic clock. This means any small variation in the timing is due to a change in relative motion. As the cosmic gravitation waves ripple past a pulsar, its observed timing changes slightly. The shift isn’t large enough to observe with an individual pulsar, but it is large enough that a statistical analysis of many pulsars reveals the gravitational waves.

MeerKAT results showing pulsar correlations across the sky. Credit: Miles, et al

In the 2023 results, NANOGrav found evidence of cosmic gravitational waves but didn’t have enough data to pin down the source. But even this was a tremendous result. It took 15 years of observations just to prove the existence of these cosmic waves. Now a new observatory has released a data set, and it’s a game changer.

The MeerKat radio array is a collection of 64 antennas located in South Africa and run by the South African Radio Astronomy Observatory (SARAO). This week, SARAO released a series of papers on their results after just four and a half years. Where NANOGrav looked at 67 millisecond pulsars, MeerKAT gathered data on 83. It observed these pulsars with a similar resolution as NANOGrav, but did so in a third of the time. These results again confirm the existence of cosmic gravitational waves, but like the NANOGrav don’t confirm the origin. We still need more data to prove they are generated by binary black holes in the Milky Way. But now that we have two observational teams working on it, that necessary evidence should be found in the relatively near future.

Reference: Agazie, Gabriella, et al. “The NANOGrav 15 yr data set: Evidence for a gravitational-wave background.” The Astrophysical Journal Letters 951.1 (2023): L8.

Reference: Miles, Matthew T., et al. “The MeerKAT Pulsar Timing Array: The 4.5-year data release and the noise and stochastic signals of the millisecond pulsar population.” Monthly Notices of the Royal Astronomical Society (2024): stae2572.

Reference: Miles, Matthew T., et al. “The MeerKAT Pulsar Timing Array: The first search for gravitational waves with the MeerKAT radio telescope.” Monthly Notices of the Royal Astronomical Society (2024): stae2571.

Reference: Grunthal, Kathrin, et al. “The MeerKAT pulsar timing array: Maps of the gravitational-wave sky with the 4.5 year data release.” Monthly Notices of the Royal Astronomical Society (2024): stae2573.

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Radiation is a primary concern for long-duration human spaceflight, such as the planned trips to Mars, which are the stated goal of organizations such as NASA and SpaceX. Shielding is the standard way to protect astronauts from radiation during those flights. However, shielding is heavy and, therefore, expensive when it is launched off the Earth. What if, instead, astronauts could hitch a ride on a giant mass of shielding already in space that will take them directly to their destination? That is the basic thought behind a paper from Victor Reshetnyk and his student at Taras Shevchenko National University in Kyiv. 

They looked at data collected by NASA’s Horizons service and analyzed the orbits of over 35,000 Near Earth Objects (NEOs) for their trajectories to see if their paths would cross somewhere between the binary pairs of Earth-Venus, Earth-Mars, or Mars-Venus. If so, then in theory, they could be used as shielding from the deadly radiation astronauts would have to either suffer from or shield against on the trip.

Given the sheer amount of objects they looked at, they were bound to find some good candidates – and they did, with an estimated 525 making “fast” transfers of less than 180 days. They then further narrowed this list down to a reasonable speed during the approach to the planet they would start from – essentially to make sure that a crewed spacecraft could actually catch up to the asteroid without burning an absurd amount of fuel.

Fraser discusses how to make an asteroid a habitat.

That lowered the total amount of candidates down to 120, with the following breakdown:

• Earth -> Venus: 44
• Earth -> Mars: 17
• Mars -> Earth: 13
• Mars -> Venus: 2
• Venus -> Earth: 38
• Venus -> Mars: 6

In other words, there were plenty of options for hitching a ride. Granted, none of these would be exceptionally roomy – the largest is estimated to have a diameter of only .37 km. However, there is still plenty of room to fit a spaceship, as long as it’s not a Star Destroyer or Battleship from 40K.

Additionally, the authors found some asteroids that had more unique trajectories. Eleven had the possibility of doing “multiple” transfers, meaning they could go from Earth to Venus and then back or vice versa, but only one would do the same for the Venus to Mars trip. Two could even do a “double” transfer, meaning they could go from Earth to Venus to Mars or from Mars to Venus to Earth in less than one year. Anything beyond that wasn’t possible, though – they didn’t find any asteroids akin to an “Aldrin Cycler” that would go between the planets indefinitely on a known orbit.

Capturing an asteroid would be one way to use it for shielding – as Fraser discusses.

That’s not to say that asteroid doesn’t already exist – we might just not have found it yet. NEO Surveyor, a NASA mission designed to launch in 2028 to find 90% of all NEOs larger than 140m in diameter, could increase the number of known NEOs by an order of magnitude.

Using any of them for a massive radiation shield for a crewed mission would take much more dedicated work, though. Any such transformation is decades away at least – but the place to start is to find the right ones, and this paper contributes to that effort.

Learn More:
A.S. Kasianchuk & V. M. Reshetnyk – The search for NEOs as potential candidates for use in space missions to Venus and Mars
UT – A New Paper Shows How To Change An Asteroid Into A Space Habitat – In Just 12 Years
UT – Rubble Pile Asteroids Might be the Best Places to Build Space Habitats
UT – NASA Makes Asteroid Defense a Priority, Moving its NEO Surveyor Mission Into the Development Phase

Lead Image:
Illustration of the asteroid Bennu.
Credit: NASA Jet Propulsion Laboratory

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Although they are very different today, Venus, Earth, and Mars were very similar in their youth. All three were warm, with thick, water-rich atmospheres. But over time, Mars became a cold, dry planet with a thin atmosphere, and Venus became superheated, with a crushing, toxic sky. Only Earth became a warm ocean world teeming with life. But why?

We know that Mars once had vast seas. It had the right conditions for life in the beginning, but with less gravity than Earth and a weak magnetic field, Mars lost much of its atmosphere over time, and most of its water either froze beneath the surface or became chemically locked in Martian clay. If Mars had been larger and more geologically active, perhaps it would have become another living world.

Which raises the question of Venus. In terms of mass and composition, Venus seems to be nearly a twin of Earth. Its surface gravity is 90% of Earth’s. While it doesn’t have a strong magnetic field like our world, it is geologically active. We can even see evidence of volcanic activity on its surface. Venus also retained a thick atmosphere, so why is it a hell-world compared to Earth?

The most common model of early Venus is that the planet was Earth-like once. Its water-rich atmosphere would have rained upon the surface to create warm seas and rivers, just like Earth and Mars. Some models suggest that Venus could have been Earth-like until 700 million years ago. But eventually, either because of its proximity to the Sun, a lack of magnetic field, or some geological process, Venus underwent a greenhouse transformation. Its oceans dried, and its atmosphere thickened to become the deadly world we see today. Perhaps we on Earth should look at Venus as a cautionary tale of what happens when greenhouse gases dramatically increase.

Two possible histories of Venus. Credit: Constantinou, et al

But new research argues that Venus was never a wet world. While it did have a water-rich early atmosphere early on, it never retained the water, and seas never formed on our planetary sibling.

The study begins by calculating the rate at which water, carbon dioxide, and other molecules are decomposed within the atmosphere. Ultraviolet radiation striking the upper atmosphere as well as chemical interactions can break apart these molecules. To maintain stable levels of water, for example, it must be replenished through volcanic activity.

On Earth, the volcanic gases released are mostly water vapor because Earth’s interior is rich in water. This allows our planet to replace water that decomposes in our upper atmosphere. But the interior of Venus is much more dry, with only 6% of the gases being water vapor. The rest is mostly carbon dioxide and sulfur compounds. In this model, the composition of volcanic gases is the main driver of how a planet’s atmosphere evolves, not the initial composition of the atmosphere. So, with little volcanic activity, the atmosphere of Mars thinned. With dry, sulfur-rich volcanic gases, Venus became a greenhouse world. With water-rich volcanic gases, Earth remained an ocean planet.

Currently, there is evidence for both evolutionary models on Venus, and neither can be ruled out. Future projects such as NASA’s DAVINCI mission could give us a richer view of the Venusian atmosphere, but until then, it remains to be seen whether the fate of a planet is written in its rock or its sky.

Reference: Constantinou, Tereza, Oliver Shorttle, and Paul B. Rimmer. “A dry Venusian interior constrained by atmospheric chemistry.” Nature Astronomy (2024): 1-10.

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How can artificial intelligence (AI) help astronauts on long-term space missions? This is what a recent study presented at the 2024 International Astronautical Congress in Milan, Italy, hopes to address as an international team of researchers led by the German Aerospace Center introduce enhancements for the Mars Exploration Telemetry-Driven Information System (METIS) system and how this could help future astronauts on Mars mitigate the communications issues between Earth and Mars, which can take up to 24 minutes depending in the orbits. This study holds the potential to develop more efficient technology for long-term space missions beyond Earth, specifically to the Moon and Mars.

Here, Universe Today discusses this incredible research with Oliver Bensch, who is a PhD student at the German Aerospace Center regarding the motivation behind the study, the most significant results and follow-up studies, the significance of using specific tools for enhancing METIS, and the importance of using AI-based technology on future crewed missions. Therefore, what was the motivation behind this study regarding AI assistants for future space missions?

“Current astronauts rely heavily on ground support, especially during unexpected situations,” Bensch tells Universe Today. “Our project aims to explore new ways to support astronauts, making them more autonomous during missions. Our focus was to make the great amount of multimodal data, like documents or sensor data easily, and most importantly, reliably available to astronauts in natural language. This is especially relevant when we think about future long-duration space missions, e.g., to Mars where there is a significant communication latency.”

For the study, the researchers improved upon current METIS algorithms since current Generative Pretrained Transformer (GPT) Models and are known for producing errors based on specific environments where they are deployed. To combat this, the researchers incorporated GPTs, Retrieval-Augmented Generation (RAG), Knowledge Graphs (KGs), and Augmented Reality (AR) with the goal of enabling more autonomy for future astronauts without the need for constant communication with Earth ground stations.

The goal of the study was to develop a system that can improve astronaut autonomy, safety, and efficiency in conducting mission objectives on long-duration space missions to either the Moon or Mars. As noted, communication delays between the Earth and Mars can be as high as 24 minutes, so astronauts being able to make on-the-spot decisions could mean the difference between life and death. Therefore, what were the most significant results from this study?

“In our project we aim to integrate documents, like procedures, with live sensor data and other additional information into our Knowledge Graph,” Bensch tells Universe Today. “The stored and live updated information is then displayed in an intuitive way using augmented reality cues and natural language voice interaction, enhancing the autonomy of the astronauts. Reliable answers are ensured by backlinks to the Knowledge Graph, enabling astronauts to verify the information, something that is not possible when just relying on large language model-based assistants as they are prone to generating inaccurate or fabricated information.”

Regarding follow-up studies, Bensch tells Universe Today the team is currently working with the MIT Media Lab Space Exploration Initiative and aspires to work with astronauts at the European Space Agency’s European Astronaut Centre sometime in 2025.

As noted, the researchers integrated Generative Pretrained Transformer (GPT) Models, Retrieval-Augmented Generation (RAG), Knowledge Graphs (KGs), and Augmented Reality (AR) with the goal of enabling more autonomy for astronauts on future long-term space missions. GPTs are designed to serve as a framework for generative artificial intelligence and was first used by OpenAI in 2018.

RAGs help enhance generative artificial intelligence by enabling the algorithm to input outside data and documentation from the user and are comprised of four stages: indexing, retrieval, augmentation, and generation. KGs knowledge bases responsible for enhancing data through storing connected datasets and the term was first used by Austrian linguist Edgar W. Schneider in 1972. AR is a display interface that combines the elements of the virtual and real world with the goal of immersing the user with a virtual environment while still maintaining the real-world surroundings. Therefore, what was the significance of combining RAGs, KGs, and AR to produce this new system?

“Traditional RAG systems typically retrieve and generate responses based on a single matching document,” Bensch tells Universe Today. “However, the challenges of space exploration often involve processing distributed and multimodal data, ranging from procedural manuals and sensor data to images and live telemetry, such as temperatures or pressures. By integrating KGs, we address these challenges by organizing data into an interconnected, updatable structure that can accommodate live data and provide contextually relevant responses. KGs act as a backbone, linking disparate sources of information and enabling astronauts to access cohesive and accurate insights across multiple documents or data types.”

Bensch continues, “AR enhances this system by offering intuitive, hands-free interfaces. By overlaying procedures, sensor readings, or warnings directly onto the astronaut’s field of view, AR minimizes cognitive load and reduces the need to shift focus between devices. Additionally, voice control capabilities allow astronauts to query and interact with the system naturally, further streamlining task execution. Although each technology provides some benefit individually, their combined use offers significantly greater value to astronauts, especially during long-duration space missions where astronauts need to operate more autonomously.”

While this study addresses how AI could help astronauts on future space missions, AI is already being used in current space missions, specifically on the International Space Station (ISS), and include generative AI, AI robots, machine learning, and embedded processors. For AI robots, the ISS uses three 12.5-inch cube-shaped robots named Honey, Queen, and Bumble as part of NASA’s Astrobee program designed to assist ISS astronauts on their daily tasks. All three robots were launched to the ISS across two missions in 2019, with Honey briefly returning to Earth for maintenance shortly after arriving at the orbiting outpost and didn’t return until 2023.

Each powered by an electric fan, the three robots perform tasks like cargo movement, experiment documentation, and inventory management, along with possessing a perching arm to hold handrails for energy conservation purposes. The long-term goal of the program is to help enhance this technology for use on lunar crewed missions and the Lunar Gateway. But how important is it to incorporate artificial intelligence into future crewed missions, specifically to Mars?

“Astronauts are currently supported by a team during training and their missions,” Bensch tells Universe Today. “Mars missions involve significant delays, which makes ground support difficult during time critical situations. AI assistants that provide quick, reliable access to procedures and live data via voice and AR are essential for overcoming these challenges.”

How will AI assistants help astronauts on long-term space missions in the coming years and decades? Only time will tell, and this is why we science!

As always, keep doing science & keep looking up!

The post Astronauts on Long Missions Will Need Personal AI Assistants appeared first on Universe Today.

Are Primordial Black Holes real? They could’ve formed in the unusual physics that dominated the Universe shortly after the Big Bang. The idea dates back to the 1960s, but so far, the lack of evidence makes them purely hypothetical.

If they do exist, a new paper suggests they may be hiding in places so unlikely that nobody ever thought to look there.

Black holes form when massive stars reach the end of their lives and suffer gravitational collapse. However, Primordial Black Holes (PBHs) didn’t involve stars. Physicists hypothesize that PBHs formed in the early Universe from extremely dense pockets of sub-atomic matter that collapsed directly into black holes. They could form part or all of what we call dark matter.

However, they remain hypothetical because none have been observed.

New research in Physics of the Dark Universe suggests researchers are not looking in the right places. It’s titled “Searching for small primordial black holes in planets, asteroids and here on Earth.” The co-authors are De-Chang Dai and Dejan Stojkovic, from Case Western Reserve University and the State University of New York, respectively.

The authors claim that evidence for PBHs could be found in objects as large as hollowed out planetoids or asteroids and objects as small as rocks here on Earth.

“Small primordial black holes could be captured by rocky planets or asteroids, consume their liquid cores from inside and leave hollow structures,” the authors write. “Alternatively, a fast black hole can leave a narrow tunnel in a solid object while passing through it. We could look for such micro-tunnels here on Earth in very old rocks,” the authors claim, explaining that the search wouldn’t involve specialized, expensive equipment.

The authors work leans heavily on other research suggesting that PBH masses between 1016 and 1010 solar masses could be candidates for dark matter. These PBHs could be captured by stars or trapped in their interiors upon formation. The PBH would slowly consume gas inside the stars.

However, these authors take it in a different direction. “We extend this idea to planets and asteroids, which can also be expected to host PBHs,” they write, explaining that the PBHs could be captured by these objects either during their creation or after their creation. Once inside a rocky body, the PBH would consume the liquid core, hollowing it out and leaving it empty.

“We have to think outside of the box because what has been done to find primordial black holes previously hasn’t worked.”

Dejan Stojkovic, SUNY

“If the object has a liquid central core, then a captured PBH can absorb the liquid core, whose density is higher than the density of the outer solid layer,” Stojkovic said.

This figure from the research illustrates what could happen when a PBH is inside a rocky body. (A) A planet is formed around a small primordial black hole (or alternatively a planet captures a black hole in its center) (B) The central core gets slowly absorbed by the black hole. If the outer shell has a strong enough compressive strength, then the shell can support itself leading to a hollow object. (C) If the liquid core becomes solid before it is completely eaten by the black hole, there will exist an empty shell between the outer layer and central core. Image Credit: Stojkovic et al. 2024.

If the asteroid or other body suffers an impact, the PBH could escape, leaving nothing but a hollow shell behind, which could be detectable.

“If the object’s density is too low for its size, that’s a good indication it’s hollow,” Stojkovic said. Studying an object’s orbit with a telescope is enough to reveal hollowness.

Another possibility the authors present is fast-moving tiny PBHs that leave microscopic tunnels in objects. “Since the cross-section of a small PHBs is very small, a fast enough PBH will most likely create a straight tunnel after passing through the asteroid,” the authors explain. In that case, a straight tunnel through an asteroid could be evidence of a PBH.

A rapidly moving PBH could leave a straight tunnel the size of its Schwarzschild radius. If the asteroid’s composition is strong, the tunnel wouldn’t collapse immediately. Image Credit: Stojkovic et al. 2024.

PBHs could also leave microscopic tunnels in rocks and other objects on Earth. “The same effect could allow detection of a PBH here on Earth if we look for sudden appearance of narrow tunnels in metal slabs,” the authors write.

What’s different about these hypothesized PBHs is detection. In other scenarios, space telescopes, gravitational wave observatories, or even monitoring distant quasars in microwaves are required to detect them. But in this work, detection is potentially much cheaper and easier.

The James Webb Space Telescope or the Laser Interferometer Space Antenna are proposed ways of detecting PBHs. Image Credit: European Space Agency CC BY-SA 4.0

“The chances of finding these signatures are small, but searching for them would not require much resources and the potential payoff, the first evidence of a primordial black hole, would be immense,” said Stojkovic. “We have to think outside of the box because what has been done to find primordial black holes previously hasn’t worked.”

“While our estimate gives a very small probability of finding such tunnels, looking for them does not require expensive equipment and long preparation, and the payoff might be significant,” the authors explain.

“You have to look at the cost versus the benefit. Does it cost much to do this? No, it doesn’t,” Stojkovic said in a press release.

This is thinking outside the box, or outside the standard model in any case. Cosmology is kind of at a standstill while we wrestle with the idea of dark matter. Could PBHs be dark matter? Could they behave like the authors suggest, and be detected in this manner?

“The smartest people on the planet have been working on these problems for 80 years and have not solved them yet,” Stojkovic said. “We don’t need a straightforward extension of the existing models. We probably need a completely new framework altogether.”

The post Could Primordial Black Holes Be Hiding in Plain Sight? appeared first on Universe Today.

One of NASA’s primary missions is to inspire the next generation of scientists and engineers to join the STEM field. It does so by producing inspirational and educational content on various platforms. But sometimes, it takes a more direct approach by rewarding students for their contributions to solving a particular problem NASA is facing. Recently, the organization announced such a challenge – the Power to Explore Challenge, which is open to submission from K-12 students until the end of January.

This challenge is part of an ongoing series of challenges that NASA has released to encourage kids to utilize a radioisotope power system (commonly known as a radioisotope thermal generator—or RTG) to enable future missions. Last year, the challenge involved coming up with a mission to a “dark, dusty, or far away place” where the benefits of RTGs, which don’t rely on solar power, would be the most obvious.

A winner was then selected in three separate age categories, detailing missions to Enceladus (Rainie Lin from Kentucky), Tethys (Aadya Karthik from Washington), and Ariel (Thomas Liu from New Jersey). The three winners received a behind-the-scenes tour of the research facilities at NASA’s Glenn Research Center in Cleveland, where much of NASA’s RTG research occurs.

Video Announcing the Challenge.
Credit – ScienceatNASA YouTube Channel

This year, there is again a call to develop missions powered by an RTG, but with a more explicit call to visit a moon somewhere in the solar system. There are plenty to choose from—the International Astronomical Union recognizes 288 orbiting planets, while there are over 470 orbiting smaller objects, like Dimorphos around Didymos, the asteroid targeted by NASA’s DART redirect mission.

The challenge is once again run by Future Engineers, an organization that emphasizes engineering education for kids. They provide the judges, who will focus on details like how feasible it is to use an RTG at the location the entrant selected, and what their “special human power” that they describe in their essay would bring to the mission.

Submissions must be a maximum of 275 words and will go through three rounds of judging. Semifinalists, finalists, and grand prize winners will be selected in March, April, and May, respectively. Once again, the grand prize winners will receive a tour of the Glenn Research Center. Semifinalists will receive a gift pack, and finalists will receive both a gift pack and a teleconference with a NASA mission expert.

Fraser discusses some challenges facing missions to other moons – especially their budgets.

Applications are open until the end of January, so if you or someone you know is interested in applying, there’s still plenty of time to conceive of a mission and polish up a 275-word essay. Who knows, you might even win a trip to Cleveland – and I can attest to it being pretty nice here in the summer – but more importantly, you might inspire the next NASA mission to one of the solar system’s numerous moons.

Learn More:
NASA – Power to Explore Student Challenge
Future Engineers – Power to Explore
UT – An Improved Radioisotope Thermoelectric Generator Could Dramatically Reduce The Weight Of Interplanetary Missions
UT – NASA is Getting the Plutonium it Needs for Future Missions

Lead Image:
Power To Explore Logo
Credit – NASA / Future Engineers

The post NASA Wants Students’ Help Designing Missions to Other Moons appeared first on Universe Today.

Our satellites are dispassionate observers of Earth’s climate change. From their vantage point they watch as pack ice slowly loses its hold on polar oceans, ice shelfs break apart, and previously frozen parts of the planet turn green with vegetation.

Now, scientists have compiled 35 years of satellite data showing that Antarctica is slowly, yet perceptibly, becoming greener.

NASA and the United States Geological Survey sent the first Landsat into space in 1975. Since then, they’ve launched eight more Landsats, with Landsat 9 being the most recent launch in 2021. Landsat data is a unique treasure trove of data about Earth and the changes it goes through, including millions of images.

Landsats have watched as forest fires burn, as urban regions expand, as glaciers melt, and as Earth goes through many other changes.

Recent research published in Nature Geoscience used 35 years of Landsat data, from Landsat 5 through Landsat 8, to measure the spread of vegetation into Antarctica. It’s titled “Sustained greening of the Antarctic Peninsula observed from satellites.” The research was co-led by Thomas Roland, an environmental scientist University of Exeter, and by remote sensing expert Olly Bartlett of the University of Hertfordshire.

“This study aimed to assess vegetation response to climate change on the AP <Antarctic Peninsula> over the past 35 years by quantifying rates of change in the spatial extent and ‘direction’ (greening versus browning), which have not yet been quantified,” the paper states.

The Antarctic Peninsula is about 1300 km (810 mi) long and is part of the larger West Antarctica Peninsula. It covers about 522,000 square kilometers (202,000 sq mi) and is the northern-most part of Antarctica. Image Credit: By krill oil – Krilloil.com, CC0, https://commons.wikimedia.org/w/index.php?curid=23043354

The research shows that the amount of land covered in vegetation on the Antarctic Peninsula has increased by more than 10x since 1986. The area of vegetated land rose from 0.86 sq. km. (0.33 sq. mi.) in 1986 to 11.95 sq. km (4.61 sq. mi.) in 2021. The coverage is restricted to the warmer edges of the peninsula, but it still indicates a shift in the region’s ecology, driven by our carbon emissions.

This vegetative colonization of Earth’s coldest region begins with mosses and lichens. Mosses are pioneer species, the first organisms to move into a newly-available habitat. These non-vascular plants are tough and hardy, and can grow on bare rock in low-nutrient environments. They create a foundation for the plants that follow them by secreting acid that breaks down rock and by providing organic material when they die.

This image shows moss hummocks on Ardley Island just off the coast of the Antarctica Peninsula. Image Credit: Roland et al. 2024.

The map makes the results of the research clear. Each of the four panels show the amount of green vegetation on the Antarctic Peninsula’s ice-free land below 300 meters (1000 ft) altitude. Each hexagon is shaded depending on how many sq. km. of it are covered in vegetation. That’s determined by the satellite-based Normalized Difference Vegetation Index (NDVI). The NDVI is based on spectrometric data gathered by the Landsat satellites during cloud-free days every March, the end of the growing season in Antarctica.

Mosses dominate the green areas, growing in carpets and banks. In previous research, Roland and co-researchers collected carbon-dated core samples from moss banks on the western side of the AP. Those showed that moss had accumulated more rapidly in the past 50 years and that there’s been a boost in biological activity. That led them to their current research, where they wanted to determine if moss was not only growing upward to higher elevations, but outward, too.

“Based on the core samples, we expected to see some greening,” Roland said, “but I don’t think we were expecting it on the scale that we reported here.”

A moss bank grows on bare rock on Norsel Point on Amsler Island. Carbon-core samples from moss banks showed an increase in growth in the past few decades. Image Credit: Roland et al. 2024.

“When we first ran the numbers, we were in disbelief,” Bartlett said. “The rate itself is quite striking, especially in the last few years.”

The Western Antarctica Peninsula is warming up faster than other parts of Earth. Not only are its glaciers receding, but the extent of the sea ice is shrinking and there’s more open water. The authors point out that changing wind patterns due to GHG emissions could be contributing.

What will happen as the ice continues to retreat and pioneer species colonize more of Antarctica? The continent has hundreds of native species, mostly mosses, lichens, liverworts, and fungi. The continent has only two species of flowering plants, Antarctic Hair Grass and Antarctic Pearlwort. What does it mean for them?

Left: Antarctic Hair Grass. Right: Antarctic Pearlwort Image Credit Left: By Lomvi2 – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=10372682. Image Credit Right: By Liam Quinn – Flickr: Antarctic Pearlwort, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=15525940

“The narrative in these places has been dominated by glacial retreat,” Roland said. “We’re starting to think about what comes next, after ice recession.”

After moss gains a foothold in a region, soil is created where there was none. That provides an opening for other organisms, both native and non-native. The risk is that the inherent biodiversity will be undermined. Tourism and other human activity can inadvertently introduce new species, and wind-borne seeds and spores can do the same. If robust organisms arrive, they can outcompete the native species. There are already a few documented instances of this happening.

This image shows a moss lawn or carpet on Barrientos Island. Image Credit: Roland et al. 2024.

The carbon-core and Landsat data is just the beginning for Roland, Bartlett, and their fellow researchers. Up-close fieldwork is the next step. “We’re at the point that we’ve said the best we can say with the Landsat archives,” Roland said. “We need to go to these places where we’re seeing the most distinctive changes and see what’s happening on the ground.”

The researches want to know what types of plant communities are establishing themselves, and what shifts are playing out in the environment.

The post Antarctica Has Gotten 10 Times Greener in 35 Years appeared first on Universe Today.

In a few billion years, our Sun will die. It will first enter a red giant stage, swelling in size to perhaps the orbit of Earth. Its outer layers will be cast off into space, while its core settles to become a white dwarf. Life on Earth will boil away, and our planet itself might be consumed by the Sun. White dwarfs are the fate of all midsize stars, and given the path of their demise, it seems reasonable to assume that any planets die with their sun. But the fate of white dwarf planets may not be lifeless after all.

More than a dozen planets have been discovered orbiting white dwarf stars. That’s a small fraction of the known exoplanets, but it tells us that planets can survive the red giant stage of a Sun-like star. Some planets may be consumed, and the orbits of survivors might be dramatically affected, but some planets retain a stable orbit. Any planets that were in the habitable zone of the star would die off, but a new study suggests that some white dwarf planets might give life the foothold it needs to evolve again.

Although white dwarfs don’t undergo nuclear fusion, they do remain warm for billions of years. Young white dwarfs can have a surface temperature of 27,000 K or more, and it takes billions of years for them to cool. Since the simple definition of a star’s habitable zone is simply the range where a planet is warm enough for liquid water, this means all white dwarfs have a habitable zone. Unlike main sequence stars, however, this region would migrate inward as the star cools. But in this new work, the authors show that white dwarfs have a habitable zone that would be warm enough for life across billions of years. For a white dwarf of about 60% of the Sun’s mass, part of the habitable zone would persist for nearly 7 billion years, which is more than enough time for life to evolve and thrive on a world. In comparison, the Earth is less than 5 billion years old.

Habitable zone of a white dwarf over time. Credit: Whyte, et al

Of course, for life to appear on a white dwarf planet, simply being warm isn’t enough. To have the kind of complex life we see on Earth, the spectrum of starlight would need to provide the right kind of energy for things like photosynthesis without ionizing the planet’s atmosphere. The spectra of white dwarfs are shifted much more to the ultraviolet than the visible and infrared, but the authors show that ionizing radiation would not be severe, and the amount of UV would allow for Earth-like photosynthesis. The optimal habitable zone would be close to the white dwarf, similar to the habitable zone of the TRAPPIST-1 red dwarf.

Just because a white dwarf planet might be home to life, that doesn’t mean they are. We know life can exist around a Sun-like star, but we’d need clear evidence to say the same is true for white dwarfs. That’s where the second part of this work comes in. Since white dwarfs are bright for their size and habitable planets would need to orbit them closely, our ability to gather evidence on them is good. The James Webb Space Telescope (JWST), for example, is sensitive enough to observe the atmospheric spectra of white dwarf planets as they transit. A few hours of observational time could be enough to get a spectrum sharp enough to detect biosignatures.

All that said, finding life on a white dwarf planet is a long shot. The planets would likely have to migrate inward during the latter part of the red dwarf stage, maintain a stable orbit, and somehow retain or recapture the kind of water-rich atmosphere you need for terrestrial life. That’s a big ask. But given how easy it might be to detect biosignatures, it’s worth taking a look.

Reference: Whyte, Caldon T., et al. “Potential for life to exist and be detected on Earth-like planets orbiting white dwarfs.” arXiv preprint arXiv:2411.18934 (2024)

The post White Dwarfs Could Have Habitable Planets, Detectable by JWST appeared first on Universe Today.

Now is the time to catch Jupiter at its best.

The King of the Planets rules the winter night skies. Early December gives sky watchers a good reason to brave the cold, as Jupiter shines at its best. Look for the regal planet rising in the east at sunset, while the Sun sets to the west.

Why Opposition?

For an outer planet, we call this point ‘opposition’ as the planet sits ‘opposite’ to the Sun from our Earthly perspective. This also means that Jupiter is above the horizon for the entire evening: low to the east at sunset, high to the south at local midnight, and setting to the west at sunset.

Opposition for Jupiter in 2024 occurs on Saturday, December 7th. Jupiter is closest to the Earth (611 million kilometers distant) a day prior on December 6th. The discontinuity exists because Jupiter is currently moving away from us, while we’re headed towards the Sun.

A double shadow moon transit from August 14th, 2024. Credit: Thad Szabo.

Jupiter reached perihelion early last year on January 20-21st, 2023, while Earth heads towards perihelion about a month from now on January 4, 2025. On an 11.9 year orbit, we won’t have another perihelion-opposition year for Jupiter until 2034.

Jupiter at opposition on December 7th. credit: Stellarium.

To the naked eye, Jupiter shines as a -2.8 magnitude ‘star’, in the constellation Taurus the Bull. This position, along with an opposition just two weeks prior to the December southward solstice on the 21st assures that Jupiter dominates the scene for northern hemisphere observers in 2024, riding high in the nighttime sky.

A ground-based view of Jupiter and its moon Io, versus the view as seen by NASA’s Juno spacecraft. Credit: NASA/Juno/Efrain Morales. Seeing Double

Zooming in on Jupiter with a telescope even at low power gives you a view similar to Galileo’s just over four centuries ago. The four major moons of Io, Europa, Ganymede and Callisto easily pop out, even in a low power binocular view. At opposition, the moons and even Jupiter itself cast shadows nearly straight back, slowly changing angle towards quadrature. While triple shadow moon transits are rare (the next one isn’t until March 20th, 2032) double shadow transits happen in seasonal cycles a few times a year. The next one involving Io and Ganymede starts on December 23rd.

A simulation of the double shadow transit coming up on December 23rd. Credit: Starry Night.

Jupiter’s fast 10 hour rotation also means that you can witness one full rotation of the gas giant in one night. This means you can spot the Great Red Spot on any given evening if you wait long enough, though to my eye, it looks more like the ‘Pale Salmon Spot’ in recent years. The major northern and southern equatorial belts are also easily apparent at low power, though the Southern Equatorial Belt has been known to pull a vanishing act roughly once a decade or so… it last did so on 2010-2011, so you could say we’re due.

JWST provides a unique infrared view of Jupiter, showing the atmospheric depth of the belts and the Great Red Spot. NASA/JWST.

Jupiter is so bright that it can cast a slight shadow, something that’s worth watching for on the freshly fallen snow. The Moon also reaches Full for December on the 15th, and passes five degrees north of the planet on the 14th, offering a chance to see Jupiter in the daytime, just before sunset.

A daytime Jupiter near the Moon. Credit: Dave Dickinson. A Teaser for Jupiter in 2025

There’s also more Jovian action in store. In the coming years, Callisto (the only major moon that can ‘miss’ Jove) resumes transits in 2026. This leads the way into the next bi-decadal mutual-eclipse season for the moons.

Don’t miss Jupiter at opposition for 2024… it’s worth braving the cold for.

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NASA has given SpaceX the contract to launch the Dragonfly mission to Saturn’s moon Titan. A Falcon Heavy will send the rotorcraft and its lander on their way to Titan in 2028, if all goes according to plan, and the mission will arrive at Titan in 2034. Dragonfly is an astrobiology mission designed to measure the presence of different chemicals on the frigid moon.

Dragonfly will be the second craft to visit Titan, along with the Huygens probe and its short visit back in 2005.

Titan is remarkable because it’s the only body besides Earth with liquids on its surface. The liquids are hydrocarbons, not water, though there may be surface deposits of water ice from impacts or cryovolcanic eruptions. Researchers think that prebiotic chemicals are also present, making the moon an enticing target to understand how far prebiotic chemistry may have advanced.

These images of Titan’s well-known hydrocarbon seas are from Cassini radar data. Image Credit: [JPL-CALTECH/NASA, ASI, USGS]

Titan is benign when it comes to powered flight; its atmosphere is dense and its gravity is weak, compared to Earth. Dragonfly is an octocopter, a large quadcopter with double rotors, that can take advantage of Titan’s flight-friendly conditions. It will travel at about 36 kmh (22 mph) and will be powered by a Radioisotope Thermoelectric Generator (RTG), a type of engine proven in multiple missions. The craft is designed to be redundant; it can lose one of its motors or rotors and still function.

Dragonfly will land near a feature on Titan called Shangri-La, east of where the Huygens probe landed. Shangri-La is one of three large sand seas near the moon’s equator.

Dragonfly’s target is the Selk impact structure, near the edge of Shangri-La. Selk is a young impact crater about 90 km (56 mi) in diameter that features melt pools, sites where liquid water and organics could mix together to form amino acids or other biomolecules. Dragonfly will initially land at some dunes near the structure then begin exploring the region and its chemistry.

Thanks largely to Cassini and Huygens, researchers have made progress understanding Titan. In a 2020 paper, researchers examined two types of craters on the moon: dune craters and plains craters. Selk is a dune crater, and in the paper, researchers said that the dune craters are richer in organics than plains craters, and in fact are almost entirely composed of organics. However, Titan’s thick atmosphere makes it difficult to observe, and these findings stem from interpreting albedo and emissivity.

Selk and the other dune craters may have originally had more water ice, according to the research, but much of it’s been eroded away. However, there was a long period of time where the water ice was present, and Dragonfly is heading for Selk to examine the chemistry in the crater and to try and determine if water and organics interacted and if prebiotic chemistry made any headway.

It’s up to SpaceX’s Falcon Heavy to send Dragonfly on its way to Titan. Falcon Heavy has 11 launches under its belt, including the launch of the Europa Clipper in October. After Falcon Heavy launches Dragonfly, the spacecraft will perform one flyby of Earth to gain additional velocity.

It’ll take six years for Dragonfly to reach Titan, and just as it arrives, the entry capsule will separate from the cruise module. With the help of an aeroshell and two chutes, the lander will endure an approximately 105-minute descent. At approximately 1.2 km above the surface, the lander will deploy its skids, and based on its lidar and radar data, will perform and autonomous landing.

From its landing site, Dragonfly will deploy itself and perform a series of flights up to 8km (5 mi) long. There’s diverse geology in the region, and the rotorcraft will acquire samples and then analyze them during Titan’s nights, which last about 8 Earth days or about 192 hours. After that, it will head to the Selk crater.

Titan is an important astrobiology target in our Solar System, and unlike the frozen ocean moons Europa and Enceladus, there’s no added complexity of somehow working its way through thick ice before its potentially biological environment can be examined.

SpaceX’s Falcon Heavy rocket sends NASA’s Europa Clipper into space from its Florida launch pad. If all goes well, the Falcon Heavy will launch the Dragonfly mission to Titan in July, 2028. (NASA Photo / Kim Shiflett)

But for all of this to succeed, it needs a successful launch first. NASA is paying SpaceX about $256 million to launch Dragonfly, and it the launch goes off without a hitch, it’ll be money well-spent.

The post Dragonfly is Going to Titan on a Falcon Heavy appeared first on Universe Today.

Even some fields that seem fully settled will occasionally have breakthrough ideas that have reverberated impacts on the rest of the fields of science and technology. Mechanics is one of those relatively settled fields – it is primarily understood at the macroscopic level, and relatively few new breakthroughs have occurred in it recently. Until a few years ago, when a group of Harvard engineers developed what they called a totimorphic structure, and a recent paper by researchers at ESA’s Advanced Concepts Team dives into detail about how they can be utilized to create megastructures, such as telescope mirrors and human habitats in space.

First, it’s worth understanding what a totimorphic structure is. It is a series of triangular structures with a beam, a lever, and two elastic bands acting as springs. Given the proper configuration, the elastic bands can hold the lever at a set position in what mechanics researchers call “neutral” – i.e., without any external force being applied.

One important aspect is that the lever can be held at any position, essentially making it an analog positioning system that doesn’t have any set points where it must necessarily rest. Another important aspect is that two or more can be combined in an hourglass-looking shape, allowing the structure to take on literally any form in either 2D or 3D space and be stable in that form.

There are plenty of novel ideas for huge telescopes, as Fraser discusses

That second part is the critical feature that the researchers at ESA were interested in. Such a flexible structure would be useful in several applications, including building domed habitats or creating a telescope with an adjustable focal length that doesn’t rely on complex actuators. So, they developed a method for simulating these structures and applying them to those two use cases.

Since these modular units are physical structures, they must still abide by some rules. The three rules of these structures are that the beam and lever both have fixed lengths and that the lever must be connected on one of its ends to the midpoint of the beam. It would be interesting to see how these structures could use different types of materials for the lever or beam that would potentially allow them to change, but that’s still on the to-do list for researchers somewhere.

With those requirements in mind, the researchers set up a series of Python scripts that solve optimization problems associated with both configurable structures. The optimized features are different for either the habitat or the mirror. Still, both use the fact that the totimorphic structure is “analog,”—meaning it can continuously and stably move from one state to another without having to “jump” between them.

Video describing the mechanics of totimorphic materials.
Credit – Rajamanickam Antonimuthu YouTube Channel

The results were promising, though they show that physically realizing this system would be difficult. They also point out that an AI would be well-placed to understand the properties of the structures created by combining loads of these modular units, similar to how it is possible for AI to fold proteins in innumerable ways without ever physically experiencing them.

A lot of work will still be done with this novel technology, though putting these systems to the test in an actual experimental environment is probably pretty close. If the ESA or another team can build a functional variable focal point mirror out of this new structure, that would be a breakthrough worthy of celebration.

Example of an hourglass-shaped “unit cell” and the positions it can be put into.
Credit – Dold et al.

Learn More:
Dold et al. – Continuous Design and Reprogramming of Totimorphic Structures for Space Applications
UT – What’s the Best Material for a Lunar Tower?
UT – Using Smart Materials To Deploy A Dark Age Explorer
UT – NASA is Testing out new Composite Materials for Building Lightweight Solar Sail Supports

Lead Image:
Depiction of the two use cases in the current study – habitat domes and variable focal length mirrors.
Credit – Dold et al.

The post A New Reconfigurable Structure Could Be Used to Make Space Habitats appeared first on Universe Today.

In our search for exoplanets, we’ve found that many of them fall into certain types or categories, such as Hot Jupiters, Super-Earths, and Ice Giants. While we don’t have any examples of the first two in our solar system, we do have two Ice Giants: Uranus and Neptune. They are mid-size gas planets formed in the cold outer regions of the solar system. Because of this, they are rich in water and other volatile compounds, and they are very different from large gas giants such as Jupiter. We still have a great deal to learn about these worlds, but what we’ve discovered so far has been surprising, such as the nature of their magnetic fields.

When the Voyager 2 spacecraft flew past Uranus and Neptune in the 1980s, it found that neither world had a strong dipolar magnetic field like Earth’s. Instead, each had a weaker and more chaotic magnetic field, similar to that of Mars. This was surprising given what we understand about planet formation.

Models for the interior structures of the ice-giant planets Uranus and Neptune. Credit: Burkhard Militzer, UC Berkeley

In a planet’s youth, the interior becomes very hot due to gravitational compression. This would allow heavier material such as iron to sink to the core, while lighter material such as water would move toward the surface. For Earth, this created a nickel-iron core with a crust of silicates, water, and organics. The tremendous heat in the core would also allow for a convective region, where hot core material rises a bit before cooling and sinking, creating a circular flow of dense material. In Earth, this convective iron region generates our planet’s strong magnetic field. Since Uranus and Neptune likely have an Earth-sized metallic core, we would expect them to have a similar convection region generating a similar magnetic field. But that isn’t what we observe.

After the Voyager 2 discovery, it was thought that perhaps some mechanism prevented a convection region from forming. Perhaps the layers within a gas giant don’t mix, similar to the separation of oil and water. But the details remained unknown. Since we can’t create the tremendously high-density, high-pressure conditions of a gas giant’s core in the lab, we had no way to test various models. We also haven’t sent another probe to either planet, so we have no way to gather new data in situ.

Simulated phase transitions for ice giant interiors. Credit: Burkhard Militzer, UC Berkeley

One approach that could work to solve the mystery would be to use computer simulations. However, simulating the interactions of hundreds of molecules to calculate their bulk properties is extremely intensive. Too complex for computer systems of a decade ago. But a new study has simulated the bulk properties of more than 500 molecules, which is enough to calculate how an ice giant’s layers form.

The simulations show how water, methane, and ammonia in the middle region of Uranus and Neptune separate into two unmixable layers. This primarily occurs because hydrogen is squeezed out of the deep interior, which limits how mixing can occur. Without a convection zone in these layers, the planets cannot form a strong dipolar magnetic field. Uranus likely has a rocky core about the size of Mercury, while Neptune likely has a rocky core about the size of Mars.

Future lab experiments could confirm some of these bulk properties, and there is a proposed mission to Uranus that would gather data to confirm or disprove this model.

Reference: Militzer, Burkhard. “Phase separation of planetary ices explains nondipolar magnetic fields of Uranus and Neptune.” Proceedings of the National Academy of Sciences 121.49 (2024): e2403981121.

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