Science

Athayde Tonhasca Júnior contributes another text-and-photo essay to the site, this time showing how a thorough knowledge of ecology is required to save a declining species. His ID’s and captions are indented, and you can enlarge his photos by clicking on them.

The butterfly, the plant, and the ant

All news is bad news, it seems, especially about the environment. Melting glaciers, oceans choked with plastic, relentless deforestation, extinctions. In the face of such a depressing deluge, we could do with a feel-good tale. And as inspiring tales go, it’s hard to beat the Large Blue Story.

The large blue butterfly (Phengaris arion) has always been rare in Britain, but its numbers were found to be alarmingly low by 1972 and falling steadily thereafter. In 1979, it became extinct in the British Isles. At first, collectors were blamed for the large blue’s demise, which was a reasonable explanation considering the rarity and the appeal of such a beautiful butterfly. But soon attention was directed to another possibility: the depletion of wild thyme (Thymus praecox), the main food for the butterfly’s early larval instars (developmental stages). It turned out that food losses contributed to the large blue extinction, but the plot was considerably thicker.

The large blue butterfly, Phengaris arion. The species’ taxonomy is a matter of dispute, so it is also known as Maculinea arion © PJC&Co, Wikimedia Commons:

The large blue and about 75% of the 6,000 or so related species (family Lycaenidae) are myrmecophilous, that is, they are associated with ants. These butterfly-ant relationships vary in form and intensity, but in the case of the large blue, red ants (Myrmica spp.) mean food: without them, the butterfly cannot survive.

A female large blue lays her eggs on the flower buds of wild thyme – wild marjoram (Origanum vulgare) would do, but it usually flowers too late in the season for the butterfly. The emerging caterpillars eat the wild thyme flower heads and seeds for the first few weeks of their lives, like any ordinary butterfly. Siblings are also fair game: if two eggs hatch on the same flower, one baby caterpillar will eat the other. Then the surviving one goes full Dr Jekyll and Mr Hyde.

The grown caterpillar drops to the ground and starts releasing substances that attract worker ants, including pheromones that mimic the aroma of red ant larvae. When an ant bumps into it, the caterpillar stretches and twists to assume the shape of an ant larva. So instead of attacking the juicy, soft and nutritious caterpillar, the chemically mesmerised ants take their ‘stray young’ back to their nest. There the caterpillar is cared for just like the ants’ own brood.

Once inside an ant nest, some lycaenid species adopt a cuckoo lifestyle; they induce the ants to nurse and feed them through regurgitation. Not the large blue (and some related species): they feed on ant larvae, all the while secreting sugary substances to keep the ant workers happy.

A greater large blue (P. arionides) caterpillar feeding on M. kotokui larvae © Ueda et al., 2016:

The caterpillar carries on eating ant grubs until it pupates the following spring. The emerging adult crawls to the surface and seeks refuge in the nearby vegetation, where it expands its wings and flies away in search of a mate.

A gravid female butterfly (1) is attracted to wild marjoram (2) and lays her eggs on suitable flower buds (3). A fourth-instar caterpillar drops to the ground and is ‘adopted’ by ants (4). The caterpillar spends 11 months inside the ants’ nest, feeding on their brood (5) © Casacci et al., 2019:

The above was a summary of the complex biology and ecology of the large blue: UK butterflies has the full story.

The large blue’s reliance on wild thyme and red ants has been known for a long time, but none of the conservation efforts prevented its extinction in 1979. Things started to change when a PhD student – today Professor Jeremy Thomas, OBE, made a crucial discovery. Not just any red ant would do for the large blue. It needs one specific species: M. sabuleti (M. scabrinodis is an alternative host, but butterfly survival is poor with this ant).

Myrmica sabuleti, the crucial host for the large blue © B. Schoenmakers, Wikimedia Commons.

Thomas’ findings opened a whole new perspective for large blue conservation. If M. sabuleti populations are not doing well, the butterfly cannot do well either, regardless of the quantity and condition of the host plant.

It turns out that the survival and abundance of this ant depend largely on one factor: sunshine, which warms their nests. If grasses that grow alongside wild thyme are too tall, the ant nests will become shaded, cold and wet: the colonies will fail or be too small to sustain large blue populations. One caterpillar may require 200 ant larvae to reach adulthood, and about 350 ant workers may be needed to rear a single caterpillar. The conclusion from these findings was that fencing, thought to help the butterfly by keeping thyme-munchers at bay, is actually bad for the ants.

Wild thyme in full sunshine maintains healthy M. sabuleti colonies © GT1976, Wikimedia Commons:

Armed with this information, Nature Conservancy (now Natural England) and the Centre for Ecology and Hydrology launched a reintroduction programme, and its linchpin was the creation and management of adequate conditions for both the butterfly and the ant. Conservation organisations, land managers and volunteers set out to monitor large blue and M. sabuleti populations, manage grazing to keep the grass short, clear scrub and plant wild thyme. When a pilot site was considered in favourable condition in 1983, large blue specimens were brought in from Sweden. More releases followed at several suitable sites during subsequent years. Today, large blue colonies are more abundant and larger than they were in the 1950s.

The rescue of the large blue butterfly is a textbook case of species conservation, known and celebrated around the world. It inspires and shows us that science, hard work and goodwill go a long way to restore and protect our natural world.

A classic scene from several high sci-fi movies and shows is when the characters approach their new spaceship in space for the first time. It is typically attached to a massive structure – think of the Kuat Drive Yards in Star Wars or the Utopia Planitia Fleet Yards around Mars in Star Trek. These gigantic structures play a role akin to what dry docks do for modern navies – they allow for the construction of ships in a relatively controlled environment with access to tools and equipment specialized for their construction. That is the idea behind a new NASA Institute for Advanced Concepts (NIAC) grant to ThinkOrbital, a company specializing in In-space assembly, manufacturing, and construction (ISAM&C). Their idea is to build a “Construction Assembly Destination” in orbit to build spacecraft in space.

That might seem like a lofty goal, but ThinkOrbital has some pedigree in doing ISAM&C tasks that no one else has done before. In May 2024, they launched and successfully tested the first-ever weld in space. The mission flew on a Falcon 9, spot-welded together some quarter-inch pieces of aluminum, and returned it to Earth, where the welds were closely examined.

They used a method called electron beam welding, which has several advantages for use in space. First, it doesn’t require as much power as a traditional arc welder—only around 2KW, equivalent to a household iron. Second, it doesn’t create a lot of heat, which can degrade the metal being welded and cause issues like splintering, which can become dangerous in zero-gravity situations.

Video describing the ThinkOrbital welder launch and test.
Credit – ThinkOrbital YouTube Channel

Doing a simple weld is a far cry from building an entire floating dry dock, but it is a step in that direction. Vojtech Holub, ThinkOrbital’s co-founder and CIO, said in an interview with Fraser that the company had actually submitted a proposal to NIAC for a more moderate step in the development of ISAM&C technology. However, the idea for a space station four times the size of the ISS “was not deemed futuristic enough.”

That rejection inspired the company to go bigger – by suggesting an entire orbital construction platform. In the interview, Dr. Volub talks about creating an interior space of 4,000 cubic meters by launching exterior plates akin to the hexagons on a soccer ball and welding them together in space using the company’s existing welder technology. In theory, if the process can be repeated, you could even build a large enough station to make something “up to [the size of] an Imperial Star Destroyer,” according to Dr. Holub.

There are some obvious difficulties in scaling up to that level, including requiring thicker plates and how to introduce gravity to any human occupants. Still, the general idea is scalable well beyond anything currently in orbit. As part of the NIAC grant, Dr. Holub and his team will have to develop a concept of operations (or CONOPS) for the development of the station, including how many launches it would take, what kind of structural loads it would be under, and how it would be assembled once it was up there.

The Orb2 was the original concept, introduced in a paper by Vojtech Holub, that spawned the idea of ThinkOrbital.
Credit – ThinkOrbital YouTube Channel

With answers to those questions in hand, ThinkOrbital would potentially be given a Phase II NIAC grant that would allow them to start building some prototypes to de-risk the technology. But they’ve got to complete Phase I first and compete with plenty of other ideas that NIAC has selected. If they are picked for a Phase II grant, though, it could move the start-up from concept to the reality of building a massive space for constructing space infrastructure – something humanity will need when it expands more throughout the solar system.

Learn More:
NASA / ThinkOrbital – Construction Assembly Destination
Vojtech Holub – Orb2: Spherical Space Station Designed for Single Launch and On-Orbit Assembly
UT – Blue Origin Announces the “Orbital Reef,” the Space Station they Plan to Build in Orbit
UT – Gateway Foundation Gives a Detailed Update on its Voyager Station Concept

Lead Image:
Artist concept highlighting the novel approach proposed by the 2025 NIAC awarded selection of Construction Assembly Destination
Credit – NASA/Ryan Benson/ThinkOrbital

The post Space Shipyards Could Build Missions in Orbit appeared first on Universe Today.

Exoplanets have captured the imagination of public and scientists alike and, as the search continues for more, researchers have turned their attention to the evolution of metallicity in the Milky Way. With this answer comes more of an idea about where planets are likely to form in our Galaxy. They have found that stars with high-mass planets have higher metallicity than those with lower amounts of metals. They also found that stars with planets tend to be younger than stars without planets. This suggests planetary formation follows the evolution of a galaxy with a ring of planet formation moving outward over time. 

The search for exoplanets has largely been one of surveying nearby stars.  That generally means we are exploring stars in our region of the Galaxy. As technology develops, our ability to detect them improves and to date, nearly 6,000 planets have been discovered around other stars. A number of different techniques have been used to find them such as the transit method – which detects the dimming of a star’s light due to the presence of the passage of a planet, or the radial velocity method which measures the wobble of a star due to the gravitational tug of a planet. 

This artist’s impression depicts the exomoon candidate Kepler-1625b-i, the planet it is orbiting and the star in the centre of the star system. Kepler-1625b-i is the first exomoon candidate and, if confirmed, the first moon to be found outside the Solar System. Like many exoplanets, Kepler-1625b-i was discovered using the transit method. Exomoons are difficult to find because they are smaller than their companion planets, so their transit signal is weak, and their position in the system changes with each transit because of their orbit. This requires extensive modelling and data analysis.

One key aspect of planetary development in the Galaxy is the presence of metals (elements heavier than hydrogen and helium.) known as metallicity. These elements are formed during the life cycle of a star, especially during supernova explosions. They are scattered through space and form part of the interstellar medium. Understanding the abundance and distribution of metals provides an insight into the age, history and formation rates of stars and planets. 

The Milky Way. This image is constructed from data from the ESA’s Gaia mission that’s mapping over one billion of the galaxy’s stars. Image Credit: ESA/Gaia/DPAC

A team of researchers led by Joana Teixeira from the University of Porto in Portugal have been exploring something known as the Galactic Birth Radii (rBirth) This term relates to the distance from galactic centre that stars and therefore planets are forming. Using photometric, spectroscopic and astrometric data, the team were able to estimate the ages of two groups of stars, those with planets and those without. This enabled them to rBirth for exoplanets based upon the original star positions (having calculated them from their age and levels of metals present within.)

The results of the analysis showed that stars hosting planets had a higher [Fe/H], are younger and were born closer to the centre of the galaxy than those without (Fe/H refers to the amount of iron relative to the amount of hydrogen in a star or galaxy, where the Sun is [Fe/H]=0.3.) The team went further to state that from one data set (from the Stellar Parameters of Stars with Exoplanets Catalog,) the results suggest that stars hosting high mass planets have a different iron to hydrogen radio and age distribution than stars with at least one low mass planet and those with only low mass planets. 

The ESA/NASA Solar Orbiter has given us our highest resolution images of the Sun ever. They show us sunspots, plasma, and magnetic fields, and more. Image Credit: ESA

The research reveals that high mass planets or in other words terrestrial planets tend to form around stars with higher [Fe/H] and younger stars compared to low mass. Similarly, those with a mixture of high and low mass planets also formed around higher [Fe/H], young stars. 

It’s an interesting study worthy of further investigations. Understanding that Earth-like planets tend to form around star systems that formed around the inner regions of the Galaxy. Here the supply of metals is more abundant and, even though the stellar systems can migrate to outer regions of the Milky Way it gives a better focus on the hunt for planetary systems beyond our own. 

Source : Where in the Milky Way Do Exoplanets Preferentially Form?

The post Planet Formation Favors the Metal-Rich Inner Milky Way appeared first on Universe Today.

The rate of warming in the oceans has more than quadrupled since 1985, suggesting global warming in general has undergone a marked acceleration

Artificial Intelligence (AI) has the potential to transform aging research and help people live healthier, longer lives.

Astronomers and engineers have developed a specialized system for their radio telescope to rapidly detect mysterious fast radio bursts and other space phenomena.

Astronomers have found two planets around two separate stars that are succumbing to their stars’ intense heat. Both are disintegrating before our telescopic eyes, leaving trails of debris similar to a comet’s. Both are ultra-short-period planets (USPs) that orbit their stars rapidly.

These planets are a rare sub-class of USPs that are not massive enough to hold onto their material. Astronomers know of only three other disintegrating planets.

USPs are known for their extremely rapid orbits, some completing an orbit in only a few hours. Since they’re extremely close to their stars, they’re subjected to intense heat, stellar radiation, and gravity. Many USPs are tidally locked to their star, turning the star-facing side into an inferno. USPs seldom exceed two Earth radii, and astronomers think that about 1 in 200 Sun-like stars has one. They were only discovered recently and are pushing the boundaries of our understanding of planetary systems.

There are plenty of unanswered questions about USPs. Their formation mechanism is unclear, though they likely migrated to their positions rather than formed there. They’re difficult to observe because of their proximity to their stars, making questions about their structures difficult to answer.

Fortunately, two separate teams of researchers have spotted the two disintegrating USPs. As they spill their contents out into space in tails, they’re giving astronomers an opportunity to see what’s inside them.

The new observations are in two new papers available at the pre-press site arxiv.org. One is “A Disintegrating Rocky Planet with Prominent Comet-like Tails Around a Bright Star.” The lead author is Marc Hon, a postdoctoral researcher at the MIT TESS Science Office. This paper is referred to hereafter as the MIT study.

“We report the discovery of BD+054868Ab, a transiting exoplanet orbiting a bright K-dwarf with a period of 1.27 days,” the authors write. The TESS spacecraft found the planet, and its observations “reveal variable transit depths and asymmetric transit profiles,” the paper states. Those are characteristics of dust coming from the doomed planet and forming tails: one on the leading edge and one on the trailing edge. Dust particle size in each tail is different, with the leading trail containing larger dust and the trailing tail containing finer grains.

This figure from the team’s modelling illustrates some of their findings. “A view from above the planetary orbit, looking down at the x ? y plane in which the planet is orbiting counterclockwise. The trails indicate the accumulated trajectories of the dust grains over time. There are two distinct trails that correspond to the leading and trailing dust tails,” the authors explain. The planet is not to scale in this image, but the host star is. Image Credit: Hon et al. 2025.

“The rate at which the planet is evaporating is utterly cataclysmic, and we are incredibly lucky to be witnessing the final hours of this dying planet’,'”

Marc Hon, MIT TESS Science Office

“The disintegrating planet orbiting BD+05 4868 A has the most prominent dust tails to date, “said lead author Hon. “The dust tails emanating from the rapidly evaporating planet are gigantic. Its length of approximately 9 million km encircles over half the planet’s orbit around the star every 30 and a half hours,” he added.

The MIT study shows that the planet is losing mass at the rate of 10 Earth masses of material per billion years. Since the object is probably only roughly the size of Earth’s Moon, it will be totally destroyed in only a few million years. “The rate at which the planet is evaporating is utterly cataclysmic, and we are incredibly lucky to be witnessing the final hours of this dying planet,” said Hon.

The host star is probably a little older than the Sun and has a companion red dwarf separated by about 130 AU. The authors think that the planet is a great candidate for follow-up studies with the JWST. Not only is the star bright, but the transits are deep. Because of the leading and trailing tails, the transits can last up to 15 hours.

The Las Cumbres Observatory captured this image of the two stars. The main sequence star is on the right, and its red dwarf companion is on the left. Image Credit: LCO/Hon et al. 2025.

“The brightness of the host star, combined with the planet’s relatively deep transits (0.8?2.0%), presents BD+054868Ab as a prime target for compositional studies of rocky exoplanets and investigations into the nature of catastrophically evaporating planets,” they explain.

“What’s also highly exciting about BD+05 4868 Ab is that it has the brightest host star out of the other disintegrating planets —about 100 times brighter than K2-22—establishing it as a benchmark for future disintegrating studies of such systems,” said Avi Shporer, a Research Scientist at the MIT Kavli Institute for Astrophysics and Space Research and a co-author of the MIT paper. “Prior to our study, the three other known disintegrating planets were around faint stars, making them challenging to study,” he added.

The second paper is “A Disintegrating Rocky World Shrouded in Dust and Gas: Mid-IR Observations of K2-22b using JWST.” The lead author is Nick Tusay, a PhD student at Penn State working in the Center for Exoplanets and Habitable Worlds. This paper is hereafter referred to as the Penn State study.

“The effluents that sublimate off the surface and condense out in space are probably representative of the formerly interior layers convectively transported to the molten surface,” the authors write. In this work, astronomers were able to observe its debris with the JWST’s MIRI and also with other telescopes. The observations show that the material coming from the USP is not likely to be iron-dominated core material. Instead, they’re “consistent with some form of magnesium silicate minerals, likely from mantle material,” the authors explain.

“These planets are literally spilling their guts into space for us, and with JWST we finally have the means to study their composition and see what planets orbiting other stars are really made of,” said lead author Tusay.

We can’t see what’s inside the planets in our Solar System, though seismic waves and other observations give scientists a pretty good idea about Earth’s interior. By examining the entrails coming from K2-22b, astronomers are learning not only about the planet but, by extension, about other rocky planets. The irony is that they’re so far away.

“K2-22b has an asymmetric transit profile, as the planet’s dusty cloud of effluents comes into view in front of the star, showing evidence of extended tails like a comet.”

“It’s a remarkable and fortuitous opportunity to
understand terrestrial planet interiors.”

Professor Jason Wright, Astronomy and Astrophysic, Penn State

“It’s remarkable that directly measuring the interior of planets in the Solar System is so challenging—we have only limited sampling of the Earth’s mantle, and no access to that of Mercury, Venus, or Mars—but here we have found planets hundreds of light years away that are sending their interiors into space and backlighting them for us to study with our spectrographs,” said Jason Wright, Professor of Astronomy and Astrophysics, co-author of the Penn State study, and Tusay’s PhD supervisor. “It’s a remarkable and fortuitous opportunity to understand terrestrial planet interiors,” he added.

While TESS discovered the disintegrating planet in the previous paper, Kepler found this one during its extended K2 mission. This one orbits its M-dwarf star in only 9.1 hours. Evidence of its tail is in the variability of its light curve. “The dramatic variability in lightcurve transit depth (0–1.3%) combined with the asymmetric transit shape suggests we are observing a transient cloud of dust sublimating off the surface of an otherwise unseen planet,” the MIT paper states.

As this figure from the research shows, each of K2-22b’s transits lasts about 46 minutes. Each blue point represents 8 minutes. Image Credit: Tusay et al. 2025.

According to the authors, this could be the first time we’ve seen outgassing from a vaporizing planet. “The shorter MIRI wavelength features … may constitute the first direct observations of gas features from an evaporating planet,” the paper states.

“Unexpectedly, the models that best fit these measurements seem to be ice-derived species (NO and CO2),” the authors write. Though the spectrum is broadly consistent with a rocky body, the presence of NO and CO2 is a bit of a curveball. These materials are more similar to icy bodies like comets rather than rocky planets.

“It was actually sort of a ‘who-ordered-that?’ moment,” Tusay said about finding the icy features. For this reason, the researchers are eager to point the JWST at the planet again to obtain more and better data. Multiple pathways can generate these results, and only better data can help astronomers determine what’s going on.

According to the authors, the wavelength features in the spectrum “may constitute the first direct observations of gas features from an evaporating planet.” Rather unexpectedly, the results indicate ice-derived chemical species. Image Credit: Tusay et al. 2025.

Though we’re in the early days of observing planets like this one, scientists still have some expectations. These results defy those expectations since many expected to find only the iron-core remnants of these USPs.

“We didn’t know what to expect,” said Wright, who also co-authored an earlier study on how to use JWST to probe these exoplanetary tails. “We were hopeful they might still have their mantles, or potentially even crust material that was being evaporated. JWST’s mid-infrared spectrograph MIRI was the perfect tool to check, because crustal, silicate mantle, and iron core materials would all transmit light in different ways that JWST could distinguish spectroscopically,” Wright added.

Next, both teams of scientists hope to point the JWST at BD+05 4868 Ab from the MIT study. Its star is far brighter than the other stars known to host disintegrating USPs. A bright light source makes it much easier for the JWST to get stronger results.

“What’s also highly exciting about BD+05 4868 Ab is that it has the brightest host star out of the other disintegrating planets —about 100 times brighter than K2-22—establishing it as a benchmark for future disintegrating studies of such systems,” said Avi Shporer, a Research Scientist at the MIT Kavli Institute for Astrophysics and Space Research and a co-author of the MIT project. “Prior to our study, the three other known disintegrating planets were around faint stars, making them challenging to study,” he added.

When the JWST was launched, it wasn’t aimed at observing disintegrating exoplanets. But this research shows off a new way of using the powerful telescope. Surprises like this are a part of every new telescope or observing effort, and researchers often look forward to them.

“The data quality we should get from BD+05 4868 A will be exquisite,” said Shporer. “These studies have proven the validity of this approach to understanding exoplanetary interiors and opened the door to a whole new line of research with JWST.”

The post Exoplanets Seen Falling Apart appeared first on Universe Today.

The new AI model from China's DeepSeek performs on a level with leading US models without requiring as much computing power – but despite a huge drop in their stock, it's not game over for US tech companies

The new AI model from China's DeepSeek performs on a level with leading US models without requiring as much computing power – but despite a huge drop in their stock, it's not game over for US tech companies

In the same way that terrestrial life evolved from ocean swimmers to land walkers, soft robots are progressing, too, thanks to recent research in battery development and design.

In the same way that terrestrial life evolved from ocean swimmers to land walkers, soft robots are progressing, too, thanks to recent research in battery development and design.

While floating solar -- the emerging practice of putting solar panels on bodies of water -- is promising in its efficiency and its potential to spare agricultural and conservation lands, a new experiment finds environmental trade-offs.

develop a model that can help municipalities choose optimal locations as they expand their cycling lane networks in response to growing demand.

The dwarf planet is a bizarre, cryovolcanic world. However, the organic deposits discovered on its surface so far are unlikely to originate from its interior. The organic material found in a few areas on the surface of dwarf planet Ceres is probably of exogenic origin. Impacting asteroids from the outer asteroid belt may have brought it with them.

Exoplanet exploration has taken off in recent years, with over 5500 being discovered so far. Some have even been in the habitable zones of their stars. Imaging one such potentially habitable exoplanet is the dream of many exoplanet hunters, however, technology has limited their ability to do that. In particular, one specific piece of technology needs to be improved before we can directly image an exoplanet in the habitable zone of another star – a starshade. Christine Gregg, a researcher at NASA Ames Research Center, hopes to contribute to the effort of developing one and has received a NASA Institute for Advanced Concepts (NIAC) grant as part of the 2025 cohort to work on a star shade that is based on a special type of metamaterial.

To understand the goal of Dr. Gregg and her team, it’s best first to understand what starshades do and what’s holding them back from being deployed. A starshade is designed to float in tandem with a space telescope and block out the light from a specific star, allowing the telescope to capture light directly from the much-less bright planet that is orbiting the star. That light can contain information about its size, orbital period, and even its atmospheric composition that would otherwise be lost in the overwhelming brightness of the planet’s star.

The shape of a starshade, which traditionally looks like a flower petal, might seem counterintuitive at first – if you’re trying to block a star’s light, why not just make the shape circular? But starlight coming from far away can diffract around a simple circle structure. The petals are explicitly designed to stop that from happening and completely block out even diffracted light around the shape’s edges.

Fraser interviews another Starshade expert – Dr. Markus Janson from Stockholm University

But it’s not the shape that makes it hard to deploy—it’s its size. Starshades are typically designed to be hundreds of meters across. Therefore, they are impossible to fit inside a traditional rocket fairing fully assembled. What’s more, they have to move along with the telescope—if the telescope the starshade is meant to accompany is pointed at another star and redirected, the starshade has to move with it.

The wrinkle is that the starshade is likely tens of thousands of kilometers from the telescope it is designed to assist. So, a slight change of a few degrees of inclination for the telescope would mean hundreds of thousands of kilometers of travel for its associated starshade. That kind of movement requires a lot of fuel, which is also costly due to the weight requirements of launching these objects so far away. 

No wonder a starshade has yet to be successfully deployed in space. Combining gigantic sizes that don’t fit inside rocket fairings and massive amounts of fuel to relocate every time the telescope needs to look at a different star are significant strikes against the concept. However, if humanity wants to directly image an exoplanet in the habitable zone of another star, there is still no better way to do so.

NASA animation of the deployment of a starshade

Enter Dr Gregg’s idea—she proposes using metamaterials for her starshade, which is robotically constructed in orbit. Metamaterials have several advantages over existing proposed starshades (one of which, by Nobel Prize winner John Mather, is another NIAC recipient this year). 

First, metamaterials are lighter. As with all things launched into space, being lighter means less cost – or, in this case, the ability to bring more fuel, allowing the starshade to operate longer than alternatives. 

Second, the specific kinds of metamaterials she proposes to use are much less likely to break. As she mentioned to Fraser in an interview, “The more stiffness a material has, the less damping it has. It’s just sort of a natural trade-off”. So, if a starshade is made from traditional materials, it would either be stiff and rigid but prone to vibrational strain when moving between positions or being deployed, or it would be very flexible but would have difficulty holding its shape when it’s supposed to.

This video shows phononic materials in action.
Credit – aiM Program at Duke University YouTube Channel

The metamaterial Dr. Gregg and her colleagues have proposed uses a type of material that both holds its structure well but also suppresses vibration by a unique use of a material called a phononic crystal. These were initially engineered to dissipate sound waves. This means that when used as a material in a starshade, it could dampen any feedback on the structure from things like micrometeoroid impacts, solar radiation, or even the process of deployment and assembly.

Using robots to deploy the starshade is another focal point of Dr. Gregg’s work, as she discusses with Fraser. Still, for this Phase I NIAC project, she is focusing on developing the model for starshade itself and selecting the appropriate material. As with all NIAC projects, she can apply for more funding in a Phase II round upon completion of her Phase I. If she receives it, humanity will be one step closer to seeing a giant floating petal in space – but one with very particular mechanical and structural properties.

Learn More:
NASA / C. Gregg – Dynamically Stable Large Space Structures via Architected Metamaterials
UT – In Order to Reveal Planets Around Another star, a Starshade Needs to Fly 40,000 km Away from a Telescope, Aligned Within Only 1 Meter
UT – Starshade Prepares To Image New Earths
UT – To Take the Best Direct Images of Exoplanets With Space Telescopes, we’re Going to Want Starshades

Lead Image:
Artist concept highlighting the novel approach proposed by the 2025 NIAC awarded selection of the Dynamically Stable Large Space Structures via Architected Metamaterials concept. NASA/Christine Gregg

The post Dynamically Stable Large Space Structures via Architected Metamaterials appeared first on Universe Today.

Star formation in the early Universe was a vigorous process that created gigantic stars. Called Population 3 stars, these giants were massive, extremely luminous stars, that lived short lives, many of which were ended when they exploded as primordial supernovae.

But even these early stars faced growth limitations.

Stellar feedback plays a role in modern star formation. As young stars grow, they emit powerful radiation that can disperse nearby gas they need to keep growing. This is called protostellar radiative feedback, and it takes place in addition to the restrictive effect their magnetic fields have on their growth.

However, new research shows that the growth of Pop 3 stars was limited by their magnetic fields.

The research is titled “Magnetic fields limit the mass of Population III stars even before the onset of protostellar radiation feedback.” The lead author is Piyush Sharda, an astrophysicist at the Leiden Observatory in the Netherlands. It’s available on the pre-print server arxiv.org.

Scientists observe stars forming in the modern Universe to understand how the process plays out. This is difficult because stars take so much time to form, while we’ve only been watching young stars from a great distance for a few decades. Stars are massive, energetic, complex objects that don’t give up their secrets easily.

There are many unanswered questions about star formation, but a general picture has emerged. It starts with a cloud of cold molecular hydrogen that collapses into dense cores. These cories become protostars, also called young stellar objects (YSOs). Accretion disks form around the young stars, and this is where radiative feedback comes in.

This artist’s concept shows a young stellar object and the whirling accretion disk surrounding it. NASA/JPL-Caltech

As young stars accrete mass, they heat up. They radiate this heat outward into their own accretion disks. As the material in the disk heats, it slows or even stops the accretion process. So radiative feedback limits their growth.

YSOs also rotate more rapidly than more mature stars. The rotation creates powerful magnetic fields, and these fields drive jets from the YSO’s poles. These jets steal away some of the accretion energy, limiting the stars’ growth. The jets can also disperse some of the surrounding gas, further limiting their growth.

However, the picture may look different for Pop 3 stars. To begin with, their existence is hypothetical at this point in time, though theory supports it. If they’re real, astrophysicists want to know how they formed and what their growth limits were. If they’re real, Pop 3 stars played a critical role in the Universe by forging the first metals and spreading them out into space.

According to the authors of the new research, simulations haven’t been thorough enough to explain the masses of Population 3 stars.

“The masses of Population III stars are largely unconstrained since no simulations exist that take all relevant primordial star formation physics into account,” the authors write. “We evolve the simulations until 5000 years post the formation of the first star.”

In the team’s more thorough simulations, which include magnetic fields and other factors, these early stars are limited to about 65 solar masses. “In 5000 yrs, the mass of the most massive star is 65 solar masses in the RMHD <radiation magnetohydrodynamics> simulation, compared to 120 solar masses in simulations without magnetic fields,” they write.

This figure from the research shows a panel from each type of simulation: HD (hydrodynamic), MHD (magneto-hydrodynamic), RHD (radiation-hydrodynamics including ionizing and dissociating radiation feedback), RMHD (radiation-magnetohydrodynamics). They show each simulation at 5,000 years after the first star forms. White dots show the positions of Population 3 stars. Image Credit: Sharda et al. 2025

The results show that both simulation runs that included magnetic fields are fragmented, leading to the formation of Pop 3 star clusters. That means that the evolution of the most massive Pop 3 stars in both runs is influenced by the presence of companion stars.

The difference comes down to gravity and magnetic fields working against each other. As young stars accrete mass, their gravitational power increases. This should draw more material into the star. But magnetic fields counteract the gravity. This all happens before radiative feedback is active.

The results also show that in both simulations that include magnetic fields, the amount of mass that reaches the envelope initially increases, then declines. However, the results were different in the simulations without magnetic fields. In those simulations, mass transfer from the envelope to the accretion disk is fast at first, creating a decline in the mass in the envelope and a build-up of mass in the disk. “This mass is consequently accreted by the star at a high rate,” the authors write.

This figure from the research illustrates some of the simulation results. It shows the mass enclosed within a disk of radius 500 au and height 50 au (from the midplane) around the most massive star. “The mass reservoir that can be accreted onto the central star in the MHD and RMHD runs eventually decreases as magnetic fields suppress gravitational collapse,” the authors explain.

“We learn that magnetic fields limit the amount of gas infalling onto the envelope at later stages by acting against gravity, leading to mass depletion within the accretion disk,” the authors explain. “The maximum stellar mass of Population III stars is thus already limited by magnetic fields, even before accretion rates drop to allow significant protostellar radiative feedback.”

Though Population 3 stars are only hypothetical, our theories of physical cosmology rely on their existence. If they didn’t exist, then there’s something fundamental about the Universe that is beyond our grasp. However, our cosmological theories do a good job of explaining what we see around us in the Universe today. If we’re putting money on it, place your bets on Pop 3 stars being real.

“Radiation feedback has long been proposed as the primary mechanism that halts the growth of Pop III stars and sets the upper mass cutoff of the Pop III IMF (initial mass function),” the authors write in their conclusion. They show that magnetic fields can limit stellar growth before feedback mechanisms come into play.

“This work lays the first step in building a full physics-informed mass function of Population III stars,” the authors conclude.

The post Why The First Stars Couldn’t Grow Forever appeared first on Universe Today.

I’m feeling grotty today, probably because of dysthymia compounded by lack of sleep. I hope to be okay tomorrow, but in the meantime we have show and tell. The show and tell today involves the Alpine Ibex (Capra ibex), the subject of a nice seven-minute video.  It concentrates on their remarkable ability to climb on ledges that look unclimbable, something the many goat species can do as well.  The videos mentions that young goats must “overcome their fear,” but I wonder if they really feel fear.

Note the morphological traits that have evolved in concert with this behavior, including body shape. Surely the ability to climb (a behavioral trait) preceded the evolution of things like those split hooves with soft pads, supporting Ernst Mayr’s claim that many key adaptations begin not as changes in morphology, but changes in behavior that give a premium to later morphological evolution. I just opened a book that was perhaps the most influential volume of my career, Mayr’s 1963 Animal Species and Evolution. I found this sentence on p. 604:

“A shift into a new niche or adaptive zone is, almost without exception, initiated by a change in behavior.”

Mayr was a smart guy, and was probably right. The important question, though, is, though, “do those changes in behavior have a genetic basis“? It’s hard to see, for example, how a goat with a greater propensity to climb, but not one based on genetic differences from other individuals, could possibly kick off a bout of evolutionary change, for there would be no increase of climbing behavior unless it came with an adaptive advantage that could be passed on via genes.  If the first climbers did have genetic differences from non-climbers, and climbing resulted in more of your genes being passed on, you would get an increase in the behavior over time since it conferred a reproductive advantage. (This didn’t start with some individuals climbing sheer cliffs, of course!). After that, any mutations changing the hoof or body shape would be subject to natural selection.  In this case, simple behavioral variation not based on genes wouldn’t, I think, kick off behaviors and morphologies like those shown below.

I can think of one exception: the famous case of cultural evolution of milk-drinking in British birds, first noted by Fisher and Hinde in 1949 (they studied blue and great tits). This was apparently a case of cultural evolution, which started with one or a few individuals prying the tops off milk bottles left on doorsteps and drinking the cream. This spread rapidly throughout the UK, so rapidly that it must have been a spread via imitation—that is, cultural evolution, not genetic evolution. Of course that would be followed by natural selection leading to things like prying the caps off better (beak changes?), locating milk bottles more readily, and digesting the milk. I don’t think anybody has studied any subsequent evolution in the birds (for one thing, milk isn’t delivered on doorsteps any more!); but this is one case in which a potential change in an “adaptive zone”—however you describe it—began with a simple behavioral change not based on genetic differences.

Sorry, I was just thinking on paper. Watch the video, which is amazing and instructive:

Lithium-air batteries have the potential to outstrip conventional lithium-ion batteries by storing significantly more energy at the same weight. However, their high-performance values have thus far remained theoretical, and their lifespan remains too short. A team has now proposed addition of a soluble catalyst to the electrolyte. It acts as a redox mediator that facilitates charge transport and counteracts passivation of the electrodes.

The world of quantum physics is experiencing a second revolution, which will drive an exponential leap in the progress of computing, the internet, telecommunications, cybersecurity and biomedicine. Quantum technologies are attracting more and more students who want to learn about concepts from the subatomic world -- such as quantum entanglement or quantum superposition -- to explore the innovative potential of quantum science. In fact, understanding the non-intuitive nature of quantum technology concepts and recognizing their relevance to technological progress is one of the challenges of 2025, declared the International Year of Quantum Science and Technology by UNESCO.

The world of quantum physics is experiencing a second revolution, which will drive an exponential leap in the progress of computing, the internet, telecommunications, cybersecurity and biomedicine. Quantum technologies are attracting more and more students who want to learn about concepts from the subatomic world -- such as quantum entanglement or quantum superposition -- to explore the innovative potential of quantum science. In fact, understanding the non-intuitive nature of quantum technology concepts and recognizing their relevance to technological progress is one of the challenges of 2025, declared the International Year of Quantum Science and Technology by UNESCO.