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Do We Now Have an Accurate Map of Nearby Stars?

Universe Today Feed - 11 hours 5 min ago

If the Sun has a stellar neighbourhood, it can be usefully defined as a 20 parsec (65 light-years) sphere centred on our star. Astronomers have been actively cataloguing the stellar population in the neighbourhood for decades, but it hasn’t been easy since many stars are small and dim.

Even with all of the challenges inherent in the effort, astronomers have made steady progress. Do we now have a complete catalogue?

In a new article in Research Notes of the American Astronomical Society, a pair of researchers from the Leibniz Institute for Astrophysics in Potsdam, Germany, try to understand how complete or incomplete our catalogue of the stellar neighbourhood is. The article is titled “Do We Finally Know all Stellar and Substellar Neighbors within 10~pc of the Sun?” The authors are Ralf-Dieter Scholz and Alexey Mints.

If all stars shone as brightly as main sequence stars like our Sun do, it would be easy to catalogue the stars in our neighbourhood. But they don’t. Some are so small and dim that they’re considered failed stars. We call them brown dwarfs or substellar objects.

When we look up at the night sky with the unaided eye, our view is dominated by main sequence stars and giant stars, many of which are far beyond our stellar neighbourhood. Many stars are too dim to see, like red dwarfs and brown dwarfs. In fact, Proxima Centauri, a red dwarf and our nearest neighbour, wasn’t discovered until the early 20th century.

Proxima Centauri. Credit: ESA/Hubble & NASA

In the early days of astronomy, measurements of proper motions showed that some stars that appear fixed in place are closer than other stars. All stars move and have proper motion; it’s just not always noticeable in the span of a single lifetime. High proper motion surveys of stars led to the selection of certain stars for measurements of their parallax, which helped locate more stars correctly in space. Then, in the early 20th century, as astronomy and photography were used in conjunction, photographic astrometry triggered a wave of discoveries of our solar neighbours. Those efforts showed that our nearest neighbours are red dwarfs (M dwarfs).

In the 1990s, as technology advanced, infrared sky surveys found more dim stars. “A second wave of discoveries started in the late 1990s with the advance of infrared sky surveys,” the authors write. Missions like the Two Micron All-Sky Survey (2MASS) gave us a new, unprecedented look at the sky. It found M dwarfs, brown dwarfs, and substellar objects like L, T, and Y types, and even minor planets in the Solar System. (Definitions of brown dwarfs and other substellar objects overlap.) By the year 2,000, the Sloan Digital Sky Survey came online, strengthening our catalogue of the sky.

In 1997, Henry et al. published an important paper on the solar neighbourhood titled “The solar neighborhood IV: discovery of the twentieth nearest star.” It showed that the discovery of LHS 1565, about 3.7 pc from Earth, spelled trouble for our census of the neighbourhood. “It ranks as the twentieth closest stellar system and underscores the incompleteness of the nearby star sample, particularly for objects near the end of the main sequence,” Henry et al. wrote. “Ironically, this unassuming red dwarf provides a shocking reminder of how much we have yet to learn about even our nearest stellar neighbours.”

Since about 1997, there’s been a burst of discoveries of stars within the Sun’s neighbourhood. The authors say that these seem to have filled in the gaps in our 10 pc neighbourhood. But some of the knowledge was still based on two assumptions. The first was that the survey out to 5 parsecs was complete, and the second was that the density was uniform out to 10 parsecs. “The first of these is not true, and the second is in question,” the authors write.

Where does that leave us? Up to 90 star systems could still be missing.

An artist’s conception of a brown dwarf. Brown dwarfs are more massive than Jupiter but less massive than the smallest main sequence stars. Their dimness and low mass make them difficult to detect. Image: By NASA/JPL-Caltech (http://planetquest.jpl.nasa.gov/image/114) [Public domain], via Wikimedia Commons

“Using all neighbours the luminosity and mass functions and the star-to-brown dwarf (BD) number ratio can be studied,” the authors state. Astronomers don’t fully understand the ratio of brown dwarfs to other stars, but two recent papers (1,2), in particular, have continued the work to better understand and catalogue our stellar neighbourhood’s dim members.

Earlier this year, Kirkpatrick et al. published a study claiming that a complete survey of nearby stars is possible, largely thanks to Gaia data. They found 462 objects (including the Sun) in 339 systems within 10?pc. of the Sun.

In previous work, the authors of this new paper added 16 more stars to the list. These were late M-dwarfs, some of the coolest and dimmest main sequence stars, and brown dwarfs. They also discovered a new white dwarf companion to an existing M dwarf.

But how complete is this newest survey?

The problem lies in the difficulty of detecting dim stars like brown dwarfs and late M-dwarfs. The further we look, the more difficult they are to detect. They’re also more difficult to detect in the direction of the galactic plane.

Dim objects like brown dwarfs are more difficult to detect when looking toward the galactic plane because that’s where most of the Milky Way’s mass is. Image Credit: ESA/Gaia/DPAC

The authors say that our neighbourhood stellar catalogue is still likely missing 93 stellar systems, “… corresponding to a deficit of ?21.5%,” they write. In terms of individual stars, it’s not much better: “…138 missing objects corresponding to a deficit of ?23.0%,” they write.

They broke it down even further to individual star types. We’re probably missing 28.1% of AFGK stars, -31% of white dwarfs, and ?27.8% of M-dwarfs. There’s also a higher deficit for late M-dwarfs. These deficits are higher than expected. What does it mean?

“The estimated deficits of systems and individual objects within 10?pc exceed expectations, in particular for the well-known AFGK stars,” the authors write. They conclude that the general assumption of a constant stellar density in the solar neighbourhood is incorrect. They say that small-scale density fluctuations can at least partly explain the deficits.

“Our statistical estimates show that the probability of these discrepancies being caused by random fluctuations is around 40%,” the authors conclude.

We clearly have more work to do.

The post Do We Now Have an Accurate Map of Nearby Stars? appeared first on Universe Today.

Categories: Science

A Combination Drill and Gas Conveyor Could Simplify Asteroid Extraction

Universe Today Feed - 11 hours 15 min ago

Collecting material from an asteroid seems like a simple task. In reality, it isn’t. Low gravity, high rotational speeds, lack of air, and other constraints make collecting material from any asteroid difficult. But that won’t stop engineers from trying. A team from Beijing Spacecrafts and the Guangdong University of Technology recently published a paper that described a novel system for doing so – using an ultrasonic drill and gas “conveyor belt.”

So far, three missions have successfully taken samples from an asteroid: Hayabusa-1 and -2 and OSIRIS-REx. Both Hayabusa missions used a projectile to impact the asteroid and collected the debris from that impact. OSIRIS-REx used a system called the Touch and Go Sample Acquisition Mechanism (TAGSAM), which touched down briefly on Bennu, the mission’s target asteroid, and then pulled away with a sample of its regolith.

Another mission, Rosetta, attempted a more involved sample collection process that involved anchoring to the asteroid itself. However, its lander, Philae, didn’t successfully attach to the asteroid and never managed to return samples to the Rosetta orbiter. Its collection mechanism known as the Sampling and Drilling Device (SD2) was the most similar to conventional sample collection here on Earth, and utilized a drill.

Fraser and Pamela discuss what all goes into a asteroid sample return mission.

That concept of drilling is at the heart of the new proposed system. It utilizes an ultrasonic drill to break up the regolith into small chunks. It’s pretty standard stuff and nothing to write home about, as robots have been doing so on celestial bodies for decades. However, in this case, the drill is surrounded by a system that utilizes gas to push the tiny grains of dust created by the drill up into a sample collection system.

In the paper, the researchers describe it as a “gas conveyor belt,” which pushes the small particles hard enough to allow them to float in the asteroid’s microgravity environment. According to the authors, the proposed system has several advantages. These include low cost, low power consumption, and adaptability to different sample collection site environments.

Another significant advantage is that the probe that utilizes it doesn’t need to be entirely securely anchored to the asteroid. This was the problem for Philae, but the physics of the ultrasonic drill made it possible for the probe to be lightly tethered to the asteroid without having the system for the probe away from the surface.

Visualization of how the gas and drill work together in the system.
Credit – Zhao et al.

In addition to the modeling and theory behind the development of the system, they also built a prototype. They tried it on various regolith simulants in a vacuum and under pressure. Since the experiment was only on a benchtop, they couldn’t test it in the microgravity environment. The ultrasonic drill, which has a “percussive” function similar to a hammer drill used in construction, made neatly drilled holes in a sample rock on the benchtop.

However, some work remains, including more comprehensive system testing, microgravity, and more theoretical modeling of the system’s efficacy. The authors believe this system could be integrated into China’s upcoming asteroid exploration and sample return missions, which they think will happen soon. If they do, they might get a chance to prove this novel piece of technology and move us one step closer to solving the technical challenge of asteroid sample return.

Learn More:
Zhao et al. – Gas-Driven Regolith-Sampling Strategy for Exploring Micro-Gravity Asteroids
UT – Finally, Let’s Look at the Asteroid Treasure Returned to Earth by OSIRIS-REx
UT – Asteroid Ryugu Contained Bonus Comet Particles
UT – OSIRIS-REx’s Final Haul: 121.6 Grams from Asteroid Bennu

Lead Image:
Images of the prototype drilling system in different test configurations.
Credit – Zhao et al.

The post A Combination Drill and Gas Conveyor Could Simplify Asteroid Extraction appeared first on Universe Today.

Categories: Science

China’s Chang’e-6 Probe Drops Off Samples From Moon’s Far Side

Universe Today Feed - 21 hours 35 min ago

Three weeks after it lifted off from the far side of the moon, China’s Chang’e-6 spacecraft dropped off a capsule containing first-of-its-kind lunar samples for retrieval from the plains of Inner Mongolia.

The gumdrop-shaped sample return capsule floated down to the ground on the end of a parachute, with the descent tracked on live television. After today’s touchdown, at 2:07 p.m. local time (0607 GMT), members of the mission’s recovery team checked the capsule and unfurled a Chinese flag nearby.

Chang’e-6, which was launched in early May, is the first robotic mission to land and lift off again from the moon’s far side — the side that always faces away from Earth. It’s also the first mission to bring dirt and rocks from the far side back to Earth.

“The Chang’e-6 lunar exploration mission achieved complete success,” Zhang Kejian, director of the China National Space Administration, said from mission control. Chinese President Xi Jinping extended congratulations to the mission team, the state-run Xinhua news service reported.

Chang’e-6 followed a flight plan similar to the one used for Chang’e-5, a mission that brought back samples from the moon’s Earth-facing side in 2020. After entering lunar orbit, the spacecraft sent a lander down to the moon’s South Pole-Aitken Basin region.

The lander used an onboard drill and robotic arm to collect and store samples on its ascent stage. It also gathered data about its surroundings with a radon detector, a negative-ion detector and a mini-rover. Data and telemetry were relayed between Chang’e-6 and Earth via China’s Queqiao-2 satellite.

On June 4, Chang’e-6’s ascent stage lifted off for a rendezvous with the orbiting spacecraft. The samples were transferred to a re-entry capsule, and the spacecraft left lunar orbit several days ago for the trip back to Earth. The re-entry capsule was released as the spacecraft sped about 5,000 kilometers (3,100 miles) over the South Atlantic Ocean, CNSA said in a mission update.

After an initial round of processing at the landing site in China’s Inner Mongolia region, the capsule is due to be airlifted to Beijing, where the mission’s precious cargo will be removed for distribution to researchers.

The samples are expected to include volcanic rock and other materials that could shed fresh light on the moon’s origins and compositional differences between the near side and the far side. Scientists may also learn more about resources in the moon’s south polar region. That region is of high interest because it’s thought to harbor deposits of water ice that could be used to support future lunar settlements.

NASA is targeting the south polar region for a series of robotic missions — leading up to a crewed landing during the Artemis 3 mission, which is currently scheduled for 2026. China has its own lunar ambitions, including plans for sending astronauts to the lunar surface by 2030.

The post China’s Chang’e-6 Probe Drops Off Samples From Moon’s Far Side appeared first on Universe Today.

Categories: Science

Did I Lie About My Conference Invitation? How Bad Faith Engagement Functions As A Distraction and Silencing Technique.

Science-based Medicine Feed - 22 hours 12 min ago

It's important to honestly and explicitly call out bad faith engagement for what it is and recognize how it functions as a common, but powerful rhetorical device.

The post Did I Lie About My Conference Invitation? How Bad Faith Engagement Functions As A Distraction and Silencing Technique. first appeared on Science-Based Medicine.
Categories: Science

Simulating the Last Moments Before Neutron Stars Merge

Universe Today Feed - Mon, 06/24/2024 - 6:46pm

When stars reach the end of their life cycle, they shed their outer layers in a supernova. What is left behind is a neutron star, a stellar remnant that is incredibly dense despite being relatively small and cold. When this happens in binary systems, the resulting neutron stars will eventually spiral inward and collide. When they finally merge, the process triggers the release of gravitational waves and can lead to the formation of a black hole. But what happens as the neutron stars begin merging, right down to the quantum level, is something scientists are eager to learn more about.

When the stars begin to merge, very high temperatures are generated, creating “hot neutrinos” that remain out of equilibrium with the cold cores of the merging stars. Ordinarily, these tiny, massless particles only interact with normal matter via weak nuclear forces and possibly gravity. However, according to new simulations led by Penn State University (PSU) physicists, these neutrinos can weakly interact with normal matter during this time. These findings could lead to new insights into these powerful events.

Pedro Luis Espino, a postdoctoral researcher at Penn State and the University of California, Berkeley, led the research. He was joined by fellow astrophysicists from PSU, the Theoretical Physics Institute at the Friedrich Schiller University Jena, the University of Trent, and the Trento Institute for Fundamental Physics and Applications (INFN-TIFPA). A paper describing their simulations, “Neutrino Trapping and Out-of-Equilibrium Effects in Binary Neutron-Star Merger Remnants,” recently appeared in the journal Physical Reviews Letters.

Artist’s conception of a neutron star merger. This process also creates heavy elements. Credit: Tohoku University

Originally predicted by Einstein’s Theory of General Relativity, gravitational waves (GW) are essentially ripples in spacetime caused by the collapse of stars or the merger of compact objects (such as neutron stars and black holes). Neutron stars are so named because their incredible density fuses protons and electrons together, creating stellar remnants composed almost entirely of neutrons. For years, astronomers have studied GW events to learn more about binary companions and what happens at the moment they merge. Said Pedro Luis Espino, a postdoctoral researcher at Penn State and the University of California, Berkeley, explained in a Penn State press release:

“For the first time in 2017, we observed here on Earth signals of various kinds, including gravitational waves, from a binary neutron star merger. This led to a huge surge of interest in binary neutron star astrophysics. There is no way to reproduce these events in a lab to study them experimentally, so the best window we have into understanding what happens during a binary neutron star merger is through simulations based on math that arises from Einstein’s theory of general relativity.”

While neutron stars are effectively cold, they can become extremely hot during a merger, especially at the interface (the point where the two stars are making contact). In this region, temperatures can reach the trillions of degrees Kelvin, but the stars’ density prevents photons from escaping to dissipate the heat. According to David Radice, an assistant professor of astronomy and astrophysics at the Eberly College of Science at Penn State and one of the team leaders, this heat may be dissipated by neutrinos, which are created during the collision as neutrons are smashed to form protons, electrons, and neutrinos.

“The period where the merging stars are out of equilibrium is only 2 to 3 milliseconds, but like temperature, time is relative here, the orbital period of the two stars before the merge can be as little as one millisecond,” he said. “This brief out-of-equilibrium phase is when the most interesting physics occurs, once the system returns to equilibrium, the physics is better understood.”

To investigate this, the research team created supercomputer simulations that modeled the merger and associated physics of binary neutron stars. Their simulations showed that even neutrinos can be trapped by the heat and density of the merger, that the hot neutrinos are out of equilibrium with the still cool cores, and can interact with the matter of the stars. Moreover, their simulations indicate that the physical conditions present during a merger can affect the resulting GW signals. Said Espino:

“How the neutrinos interact with the matter of the stars and eventually are emitted can impact the oscillations of the merged remnants of the two stars, which in turn can impact what the electromagnetic and gravitation wave signals of the merger look like when they reach us here on Earth. Next-generation gravitation-wave detectors could be designed to look for these kinds of signal differences. In this way, these simulations play a crucial role allowing us to get insight into these extreme events while informing future experiments and observations in a kind of feedback loop.”

This is certainly good news for gravitational wave astronomy and for scientists hoping to use GW events to probe the interiors of neutron stars. Knowing what conditions are present during mergers based on the type of GW signals produced could also provide new insight into supernovae, Gamma-ray Bursts, Fast Radio Bursts, and the nature of Dark Matter.

Further Reading: PSU, Physical Review Letters

The post Simulating the Last Moments Before Neutron Stars Merge appeared first on Universe Today.

Categories: Science

Little-studied pollutant from planes threatens the health of millions

New Scientist Feed - Mon, 06/24/2024 - 4:01pm
More than 50 million people living near airports in Europe may be at risk of health impacts from a little-studied form of air pollution produced at high levels by aircraft engines
Categories: Science

Growing Black Holes Have Much in Common With Baby Stars

Universe Today Feed - Mon, 06/24/2024 - 1:47pm

First looks would tell most observers that supermassive black holes (SMBHs) and very young stars have nothing in common. But that’s not true. Astronomers have detected a supermassive black hole (SMBH) whose growth is regulated the same way a baby star’s is: by magnetic winds.

Supermassive Black Holes are so massive that comprehending them is difficult. They can be billions of times more massive than our Sun, a number so easy to say that it trivializes their true magnitude. They grow so large through two mechanisms: mergers and accretion.

Black holes can’t be seen directly, but their existence is confirmed by observing how they alter their surroundings. SMBHs are so massive that they alter the orbits and velocities of nearby stars, a phenomenon astronomers have clearly observed. SMBHs are also visible as active galactic nuclei when they’re actively accreting material. Lastly, when black holes merge, they release gravitational waves that we can detect with facilities like LIGO/Virgo.

But there are lots of unanswered questions about how black holes grow by accretion. To try to understand how an SMBH accretes gas and acquires mass, a team of researchers observed ESO320-G030, a nearby galaxy only 120 million light years away.

Their results are in a paper titled “A spectacular galactic scale magnetohydrodynamic powered wind in ESO 320-G030.” The paper is published in the journal Astronomy and Astrophysics, and the lead author is Mark Gorski, a postdoc at Northwestern University.

One outstanding issue in the study of SMBHs concerns black hole feedback. Not all of the material that enters an SMBH’s accretion disk falls into the hole. Some is released by astrophysical jets. This is part of a process called black hole feedback, and it shapes how the black hole grows and how quickly its galaxy forms new stars.

ESO 320-G030 is interesting not only because it hosts an SMBH but also because it’s forming new stars at a rapid rate, about ten times as fast as the Milky Way. To try to understand all the processes in the galaxy’s nucleus, a team of researchers used the Atacama Large Millimetre/submillimetre Array (ALMA) to observe molecules being transported from the galaxy’s center outward.

“How galaxies regulate nuclear growth through gas accretion by supermassive black holes (SMBHs) is one of the most fundamental questions in galaxy evolution,” the authors write in their research article. “One potential way to regulate nuclear growth is through a galactic wind that removes gas from the nucleus.”

ALMA’s strength lies in its ability to see through thick gas and dust and to observe light that straddles infrared light and radio waves. It can track cold molecules by the light they emit in these wavelengths. In this research, ALMA tracked HCN (hydrogen cyanide) as it travelled through ESO 320-G030’s nucleus.

“It is unclear whether galactic winds are powered by jets, mechanical winds, radiation, or via magnetohydrodynamic (MHD) processes,” the authors write. By using ALMA to observe HCN, the researchers hoped to bring clarity.

An artist’s conception of a supermassive black hole’s jets. Credit: NASA / Dana Berry / SkyWorks Digital

ESO 320-G030 is a particular type of galaxy. It’s a luminous infrared galaxy with a very compact nucleus obscured by dust. About 30% of these types of galaxies have extremely compact nuclei with growing SMBHs or unusual starbursts. There’s clearly a lot of action in the galaxy’s nucleus, so it’s a critical target for astrophysicists and astronomers.

“Since this galaxy is very luminous in the infrared, telescopes can resolve striking details in its centre,” said Susanne Aalto, Professor of Radio Astronomy at Chalmers University of Technology. “We wanted to measure light from molecules carried by winds from the galaxy’s core, hoping to trace how the winds are launched by a growing, or soon to be growing, supermassive black hole. By using ALMA, we were able to study light from behind thick layers of dust and gas.”

There’s a debate among astronomers over the nature of black hole feedback. Galaxies have AGN-driven outflows that inject gas back into a galaxy’s nucleus, but they can’t agree on the nature of the feedback. It could be jets, mechanical winds, or radiation. Observing ESO 320-G030 with ALMA’s molecule-observing ability is a chance to wade deeply into the debate.

ALMA was able to trace the behaviour of HCN due to excitational vibration. The observations result in maps of the molecule’s movement in the galaxy’s nucleus.

This figure from the research shows an intensity-weighted velocity field of HCN in ESO 320-G030’s nucleus. The authors write, “The rough location and direction of the outflow is indicated by the dashed arrows.” The contours in the figure show that the HCN-vib emission is “extended along the outflow and that the outflow is launched from similarly rotating sides of the nucleus.” Image Credit: Gorski et al. 2024

“We can see how the winds form a spiralling structure, billowing out from the galaxy’s centre. When we measured the rotation, mass, and velocity of the material flowing outwards, we were surprised to find that we could rule out many explanations for the power of the wind, star formation for example. Instead, the flow outwards may be powered by the inflow of gas and seems to be held together by magnetic fields,” said Aalto.

As the SMBH draws material into its rotating accretion disk, the rotation creates powerful magnetic fields. The magnetic fields lift matter away from the center, creating a spiralling MHD (magnetohydrodynamic) wind. As matter is removed by the wind, the disk rotation slows. Slower rotation allows more material to fall into the hole, letting the SMBH grow more massive.

Other winds and jets in the nucleus propel material away from black holes in galaxy nuclei, but this newly discovered wind feeds material into the black hole. “In this Letter, we present compelling evidence that the outflow in ESO 320-G030 is powered by a different mechanism, an MHD wind launched prior to the ignition of an AGN,” the authors write. Since an AGN is observed when an SMBH has accreted material into its disk and the material has been heated by rotation, the wind the researchers observed is likely responsible for feeding material into the black hole’s disk, some of which falls into the hole itself.

To the astronomers behind the work, the ALMA data images are a breathtaking new insight into the winds in ESO 320-G030’s galactic nucleus. “What is spectacular about the outflow morphology is that the launching regions are apparent and connected to the rotating nuclear structure in the innermost ~12 pc,” they write. The patterns revealed by ALMA hint at the presence of a magnetized rotating wind.

The wind’s rotating element is key. “The rotation of outflows is a strong indication of magnetic acceleration,” the authors explain. If magnetic acceleration is driving it, then the other phenomena astronomers debate—AGN, astrophysical jets, or radiation—can’t be responsible.

This newly discovered wind is similar to the winds around young protostars that are accreting material and actively growing.

Artist’s conception of a star being born within a protective shroud of gas and dust. New research shows that magnetic winds aid the growth of both protostars and SMBHs. Credit: NASA

“It is well-established that stars, in the first stages of their evolution, grow with the help of rotating winds – accelerated by magnetic fields, just like the wind in this galaxy. Our observations show that supermassive black holes and tiny stars can grow by similar processes, but on very different scales.” said lead author Gorski in a press release.

This could be a big step in understanding how SMBHs grow, but the authors know it’s only one step. They need to observe more SMBHs and gather more data before anything is conclusive.

“Far from all questions about this process are answered. In our observations we see clear evidence of a rotating wind that helps regulate the growth of the galaxy’s central black hole. Now that we know what to look for, the next step is to find out how common a phenomenon this is. And if this is a stage which all galaxies with supermassive black holes go through, what happens to them next?” asks lead author Gorski.

The post Growing Black Holes Have Much in Common With Baby Stars appeared first on Universe Today.

Categories: Science

NASA Doesn't Know When Starliner Will Return From Orbit

Universe Today Feed - Mon, 06/24/2024 - 12:19pm

After helium leaks and thruster problems with Boeing’s Starliner capsule, NASA has been pushing back the return date from the International Space Station. On Friday, the agency announced they no longer had a planned return date. Instead, they will keep testing the capsule, trying to understand its issues, and seeing if they can make any fixes. Plenty of supplies are on the station, so there’s no urgent need to bring the two astronauts back to Earth.

NASA decided to cancel the planned departure of Wednesday, June 26 because of conflicting timelines with a series of planned spacewalks on the ISS, set for today (Monday, June 24), and Tuesday, July 2. The delay also allows mission teams time to review propulsion and system data.

Boeing’s CTS-100 Starliner taking off from Cape Canaveral, Florida, on June 5th, 2024. Credit: NASA

After years of delays and two recent scrubbed launch attempts, Starliner finally launched on June 5, 2024 with NASA astronauts Butch Wilmore and Suni Williams on board. Although two of the spacecraft’s thrusters failed during the flight, the spacecraft managed to reach the ISS and delivered 227 kg (500 lbs) of cargo. Additionally, five small leaks on the service module were also detected, and the crew and ground teams have been working through safety checks.

“We are taking our time and following our standard mission management team process,” said Steve Stich, manager of NASA’s Commercial Crew Program in a NASA blog post. “We are letting the data drive our decision making relative to managing the small helium system leaks and thruster performance we observed during rendezvous and docking. Additionally, given the duration of the mission, it is appropriate for us to complete an agency-level review, similar to what was done ahead of the NASA’s SpaceX Demo-2 return after two months on orbit, to document the agency’s formal acceptance on proceeding as planned.”

This first crewed flight of Starliner was supposed to validate the spacecraft as part of NASA’s Commercial Crew Program (CCP), with the hope of it working alongside SpaceX’s Crew Dragon to make regular deliveries of cargo and crew to the ISS. This mission is the second time the Starliner has flown to the ISS and the third flight test overall. During the first uncrewed test flight (OFT-1), which took place back in December 2019, the Starliner launched successfully but failed to make it to the ISS. After making 61 corrective actions recommended by NASA, another attempt was made (OFT-2) on May 22nd, 2022. That flight successfully docked to the ISS, staying there for four days before undocking and landing in the White Sands Missile Range in New Mexico.

The seven Expedition 71 crew members gather with the two Crew Flight Test members for a team portrait aboard the space station. In the front from left are, Suni Williams, Oleg Kononenko, and Butch Wilmore. Second row from left are, Alexander Grebenkin, Tracy C. Dyson, and Mike Barratt. In the back are, Nikolai Chub, Jeanette Epps, and Matthew Dominick. Photo credit: NASA

Wilmore and Williams are now  working with the Expedition 71 crew, assisting with station operations as needed and completing add-on in-flight objectives for NASA’s certification of Starliner.

Stich said that despite all the issues, Starliner is performing well in orbit while docked to the space station.

“We are strategically using the extra time to clear a path for some critical station activities while completing readiness for Butch and Suni’s return on Starliner,” he said, “and gaining valuable insight into the system upgrades we will want to make for post-certification missions.”

Mission managers will evaluate future return opportunities for Starliner and NASA said they will host a media telecon with mission leadership following a readiness review. NASA added that Starliner is actually cleared for return in case of an emergency on the space station that would require the crew to leave orbit and come back to Earth.

The post NASA Doesn't Know When Starliner Will Return From Orbit appeared first on Universe Today.

Categories: Science

Quantum ‘super behaviour’ could create energy seemingly from nothing

New Scientist Feed - Mon, 06/24/2024 - 10:00am
It should be possible to combine several quantum states, each with almost no energy, to create a single quantum state containing unexpectedly energy-rich regions
Categories: Science

Advanced Optics Could Help Us Find Earth 2.0

Universe Today Feed - Mon, 06/24/2024 - 9:58am

NASA has long been interested in building bigger and better space telescopes. Its Institute for Advanced Concepts (NIAC) has funded several methods for building and deploying novel types of telescopes for various purposes. Back in 2019, one of the projects they funded was the Dual Use Exoplanet Telescope (DUET), which would use an advanced form of optics to track down a potential Earth 2.0.

So far, the largest telescope launched into space is JWST, with a 6.5m primary mirror. However, even with that big of a mirror, it is difficult to differentiate exoplanets from their stars, which may be only a few milliarcseconds away from each other. Larger telescopes on the ground have slightly higher resolutions, but they suffer from other limitations, such as atmospheric distortion and cloud cover.

A larger telescope in space would solve many of those problems, but launching one that is simply a larger version of JWST is prohibitively expensive or just plain prohibited, depending on whether it would fit in a rocket fairing. Even Starship and other next-generation launch systems couldn’t fit a 10 m assembled primary mirror.

PI Tom Ditto gives a talk at the SETI Institute about the DUET telescope.
Credit – SETI Institute YouTube Channel

So, researchers have started to turn to alternative optical techniques that could solve this problem. One commonly known optical phenomenon is diffraction. The best-known example is the famous “slit” experiment that many kids perform in physics class. Light bends when going around an edge, and engineers can take that principle, scale it up, and build something that bends the light from far-away stars.

That is the underlying principle of DUET – it uses a technique called primary objective grating (POG) to focus specific wavelengths that might be of interest – for example, that wavelength that would show oxygen in an exoplanet’s atmosphere. In particular, DUET uses a type of POG that results in a circular spectrogram. Although this idea is novel in astronomy, it has been used in other fields. Tom Ditto, the PI on the project, was originally an artist before converting into a technologist focusing on optics.

With the NIAC Phase I funding, Ditto and his team developed a bench-top experiment that proved the technology underlying DUET. It consists of a slatted first data collection stage that focuses the light from a star of interest on a secondary stage and, thereby, a collector, which captures the data that could be translated into a circular spectrograph. 

Graphic of deployment of the slits in the outer primary of the DUET telescope.
Credit – Ditto et al.

In particular, the researchers were interested in UV light, as Earth would appear like a bright candle from far away, at least compared to light in other spectra. They tested a violet laser on their bench setup and analyzed the resulting circular spectrograph. It showed great promise for detecting something with a spectrum like Earth’s from very far away.

But there are still hurdles to overcome. One of the bigger concerns was the efficiency of the grating structure used in the experiments. Its 20% efficiency would make it barely feasible to detect the kind of faint objects the telescope is designed for. The deployment mechanism for the grating, which requires the assistance of additional spacecraft separate from the telescope itself, would also be a challenge.

How would we build large telescopes in space? Fraser explains.

That’s where the experiment stands, as NASA has not elected to support the project with a Phase II grant so far. Given the history of exoplanet discovery, it’s only a matter of time before we find Earth 2.0. What technology we will use to do so is up in the air.

Learn more:
Ditto et al. – DUET The Dual Use Exoplanet Telescope
UT – Building Space Telescopes… In Space
UT – Future Space Telescopes Could be 100 Meters Across, Constructed in Space, and Then Bent Into a Precise Shape
UT – Using Smart Materials To Deploy A Dark Age Explorer

Lead Image:
Graphic of the DUET Space Telescope Fully Deployed.
Credit – Ditto et al.

The post Advanced Optics Could Help Us Find Earth 2.0 appeared first on Universe Today.

Categories: Science

New study confirms forever chemicals are absorbed through human skin

Matter and energy from Science Daily Feed - Mon, 06/24/2024 - 9:55am
A study of 17 commonly used synthetic 'forever chemicals' has shown that these toxic substances can readily be absorbed through human skin.
Categories: Science

A hidden treasure in the Milky Way -- Astronomers uncover ultrabright x-ray source

Space and time from Science Daily Feed - Mon, 06/24/2024 - 9:55am
Astronomers uncovered that a well-known X-ray binary, whose exact nature has been a mystery to scientists until now, is actually a hidden ultraluminous X-ray source.
Categories: Science

Star clusters observed within a galaxy in the early Universe

Space and time from Science Daily Feed - Mon, 06/24/2024 - 9:54am
The history of how stars and galaxies came to be and evolved into the present day remains among the most challenging astrophysical questions to solve yet, but new research brings us closer to understanding it. New insights about young galaxies during the Epoch of Reionization have been revealed. Observations with the James Webb Space Telescope (JWST) of the galaxy Cosmic Gems arc (SPT0615-JD) have confirmed that the light of the galaxy was emitted 460 million years after the big bang. What makes this galaxy unique is that it is magnified through an effect called gravitational lensing, which has not been observed in other galaxies formed during that age.
Categories: Science

Innovative 3D printing method streamlines multi-materials manufacturing

Matter and energy from Science Daily Feed - Mon, 06/24/2024 - 9:54am
Researchers have developed a way to create complex devices with multiple materials -- including plastics, metals and semiconductors -- all with a single machine. The research outlines a novel 3D printing and laser process to manufacture multi-material, multi-layered sensors, circuit boards and even textiles with electronic components.
Categories: Science

Why antibiotic resistance could make the last pandemic look minor

New Scientist Feed - Mon, 06/24/2024 - 9:00am
People don't realise just how bad our antibiotic resistance problem is, says Jeanne Marrazzo, the top infectious disease specialist in the US
Categories: Science

Satellites are Going to Track Garbage Drifting Across the Oceans

Universe Today Feed - Mon, 06/24/2024 - 8:51am

We are all too aware of the pollution on planet Earth. There are increased amounts of plastic and garbage on the world’s beaches and debris littering the oceans. Until now, it was thought that satellites weren’t capable of tracking marine debris but a supercomputer algorithm challenges that. 300,000 images were taken every three days at a resolution of 10 metres and were able to identify large concentrations of debris. 

Upper estimates of plastic in our oceans peak at around 200 million tons! Every day it is believed another 8 million pieces of plastic make their way into the marine environment. Now, a study led by a team at the Institut de Ciencies del Mar at the University of Cadiz believe it may be possible to study and track the surface debris in the oceans. Using supercomputers and advanced algorithms, the team have shown that satellites can indeed be used. 

Using data from the European Copernicus Sentinel-2 satellite, a total of 300,000 images of the Mediterranean Sea were analysed. The images were taken every 3 days at a resolution of 10 metres. Typically of course, there is not much debris in the sea which is that big but accumulations of debris have grown to that size. The aggregations are known as ‘windrows’ and have built up as ocean currents and winds bring debris together to form large structures. 

The output from the study reveals the most polluted areas of the Mediterranean and the main entry points from the mainland. It will help us to improve our understanding of the processes and mechanisms that transport debris across the ocean and even help us to perhaps predict movement. The results also show that the amount of debris in the Mediterranean covers around 95 square kilometres.

Eastern Mediterranean Sea Area June 1993

Unfortunately the research does not help resolve the issue of pollution but it does help us understand the scale. The team propose future satellites should be equipped with detectors to monitor the debris. It would increase the ability to detect plastic in the open ocean by a factor of 20 and help to model the impact of marine pollution on first, tourism and the marine ecosystem. 

One element of the studies conclusion is that population density, geography and rainfall patterns play an important part in the accumulation of marine litter. Dry arid lands like deserts that play host to cities seem to contribute much less to marine litter while those that are much more temperate with higher rainfall seem to contribute more. 

It is also interesting to note that the majority of litter that originates from land masses seems to be confined to 15 kilometres form the coast and subsequently returns after a few days of months. The team conclude that satellite based monitoring is an essential element in our battle against litter in the ocean. The technology can also be used for the detection of other floating objects such as the loss of ships, oil spills and even search and rescue elements. 

Source : Satellites to monitor marine debris from space

The post Satellites are Going to Track Garbage Drifting Across the Oceans appeared first on Universe Today.

Categories: Science

Origami computer uses folded paper for calculations

New Scientist Feed - Mon, 06/24/2024 - 7:00am
By representing data as folds in paper, the principles of origami can theoretically be used to compute anything imaginable
Categories: Science

Mercury may have a layer of diamond beneath its grey surface

New Scientist Feed - Mon, 06/24/2024 - 7:00am
When the planet Mercury formed 4 billion years ago, conditions may have been just right to form a thick layer of diamonds below its surface
Categories: Science

Will Space Tourists Be Getting Heart Attacks in Space?

Universe Today Feed - Mon, 06/24/2024 - 6:50am

Astronauts are considered by many to be an elite bunch of people; healthy, fit and capable in many disciplines. Went they travel into space they can face health issues related to weightlessness from reduction in bone density to issues with their eyesight. These are people at the peak of physical fitness but what will happen to the rest of us when space tourism really kicks off. It is likely that anyone with underlying health issues could worsen in space. A new study suggests those with cardiovascular issues may suffer heart failure in space!

Space travel and automatic intelligence (AI) are two fabulously interesting topics. Combine them and you have a fascinating story. Dr Lex Van Loon from the Australian National University has been using AI and mathematical models to explore human physiology and the impact of space exploration. In a recent study he created digitally identical AI twins, one with an underlying heart condition. 

The interest driving the study is the advancement toward space tourism and the opening up of space to those less physically fit than astronauts. As space travel becomes more available to the mass population we will start to see a shift in demographic of space travellers to older, more wealthy individuals but they are more likely to have health issues. We will eventually see people with a whole multitude of conditions wanting to holiday in space, but what are the likely impacts. 

ESA astronaut Alexander Gerst gets a workout on the Advanced Resistive Exercise Device (ARED). Credit: NASA

Microgravity causes a redistribution of fluids around the body and can cause conditions like ‘puffy face bird leg syndrome.’ The name aptly describes the effect, the face swells up and the legs thin. It results in an increase in venous pressure in the upper body, this is fine for healthy people but heart failure sufferers are at a much higher risk. Given that there are over 100 million people around the world that suffer heart failure it is essential this is explored. 

Looking at the wide spectrum of heard failure, conditions can be grouped into two categories; a weak hart that cannot pump effectively and a heart that cannot relax and fill properly. All possible conditions need to be studied with specific ways to treat and mitigate the risk during space travel. 

This is a study that is difficult to collect real data in space so we have to turn to computer modelling to simulate the effects. The team led by Dr Loon showed that a microgravity environment leads to an increase in cardiac output (the quantity of blood pumped by the heart in a given period of time.) This is not a problem for most people but with heart failure patients it is accompanied by a rise in pressure in the left atrial region of the heart, to dangerous levels. If left unchecked, it can lead to a condition where fluid accumulates in the lungs known as a pulmonary edema, making it difficult to breathe!

With the increase in corporate interest in space travel, space tourism is slowly becoming a reality. People can already pay for trips into space but as costs come down, the number of people heading out into space will increase. Eventually, trips into space will be as common as trips to other countries. It is imperative we understand the impact on our health and what we can do to make space as widely accessible as possible without putting our health at risk. 

Source : Heart failure in space: scientists calculate potential health threats facing future space tourists in microgravity

The post Will Space Tourists Be Getting Heart Attacks in Space? appeared first on Universe Today.

Categories: Science

Speaking Event Today in Lenox, MA

Science blog of a physics theorist Feed - Mon, 06/24/2024 - 6:03am

For those of you currently in western Massachusetts or eastern upstate New York, some news: I’ll be speaking about my book today, Monday, June 24th, 5:30 pm, in Lenox, MA. At this free event, held at the local institution known simply as “The Bookstore“, I’ll read from the text and discuss its central message. After that, I’ll answer questions from the audience and sign books.


In other news — for those of you waiting (im)patiently for the audiobook, I am glad to report that there is finally some forward movement on that front. I’m still not sure how long it will take for the audio version to become available, but progress should be steady and rapid from here.

Categories: Science

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