Category: 7. Science

“Space ice” contains tiny crystals and is not, as previously assumed, a completely disordered material like liquid water, according to a new study by scientists at UCL (University College London) and the University of Cambridge.

Ice in space is different to the crystalline (highly ordered) form of ice on Earth. For decades, scientists have assumed it is amorphous (without a structure), with colder temperatures meaning it does not have enough energy to form crystals when it freezes.

In the new study, published in Physical Review B, researchers investigated the most common form of ice in the Universe, low-density amorphous ice, which exists as the bulk material in comets, on icy moons and in clouds of dust where stars and planets form.

They found that computer simulations of this ice best matched measurements from previous experiments if the ice was not fully amorphous but contained tiny crystals (about three nanometres wide, slightly wider than a single strand of DNA) embedded within its disordered structures.

In experimental work, they also re-crystallised (i.e. warmed up) real samples of amorphous ice that had formed in different ways. They found that the final crystal structure varied depending on how the amorphous ice had originated. If the ice had been fully amorphous (fully disordered), the researchers concluded, it would not retain any imprint of its earlier form.

Lead author Dr Michael B. Davies, who did the work as part of his PhD at UCL Physics & Astronomy and the University of Cambridge, said: “We now have a good idea of what the most common form of ice in the Universe looks like at an atomic level.

“This is important as ice is involved in many cosmological processes, for instance in how planets form, how galaxies evolve, and how matter moves around the Universe.”

The findings also have implications for one speculative theory about how life on Earth began. According to this theory, known as Panspermia, the building blocks of life were carried here on an ice comet, with low-density amorphous ice the space shuttle material in which ingredients such as simple amino acids were transported.

Dr Davies said: “Our findings suggest this ice would be a less good transport material for these origin of life molecules. That is because a partly crystalline structure has less space in which these ingredients could become embedded.

“The theory could still hold true, though, as there are amorphous regions in the ice where life’s building blocks could be trapped and stored.”

Co-author Professor Christoph Salzmann, of UCL Chemistry, said: “Ice on Earth is a cosmological curiosity due to our warm temperatures. You can see its ordered nature in the symmetry of a snowflake.

“Ice in the rest of the Universe has long been considered a snapshot of liquid water – that is, a disordered arrangement fixed in place. Our findings show this is not entirely true.

“Our results also raise questions about amorphous materials in general. These materials have important uses in much advanced technology. For instance, glass fibers that transport data long distances need to be amorphous, or disordered, for their function. If they do contain tiny crystals and we can remove them, this will improve their performance.”

For the study, the researchers used two computer models of water. They froze these virtual “boxes” of water molecules by cooling to -120 degrees Centigrade at different rates. The different rates of cooling led to varying proportions of crystalline and amorphous ice.

They found that ice that was up to 20% crystalline (and 80% amorphous) appeared to closely match the structure of low-density amorphous ice as found in X-ray diffraction studies (that is, where researchers fire X-rays at the ice and analyse how these rays are deflected).

Using another approach, they created large “boxes” with many small ice crystals closely squeezed together. The simulation then disordered the regions between the ice crystals reaching very similar structures compared to the first approach with 25% crystalline ice.

In additional experimental work, the research team created real samples of low-density amorphous ice in a range of ways, from depositing water vapour on to an extremely cold surface (how ice forms on dust grains in interstellar clouds) to warming up what is known as high-density amorphous ice (ice that has been crushed at extremely cold temperatures).

The team then gently heated these amorphous ices so they had the energy to form crystals. They noticed differences in the ices’ structure depending on their origin – specifically, there was variation in the proportion of molecules stacked in a six-fold (hexagonal) arrangement.

This was indirect evidence, they said, that low-density amorphous ice contained crystals. If it was fully disordered, they concluded, the ice would not retain any memory of its earlier forms.

The research team said their findings raised many additional questions about the nature of amorphous ices – for instance, whether the size of crystals varied depending on how the amorphous ice formed, and whether a truly amorphous ice was possible.

Amorphous ice was first discovered in its low-density form in the 1930s when scientists condensed water vapour on a metal surface cooled to -110 degrees Centigrade. Its high-density state was discovered in the 1980s when ordinary ice was compressed at nearly -200 degrees Centigrade.

The research team behind the latest paper, based both at UCL and the University of Cambridge, discovered medium-density amorphous ice in 2023. This ice was found to have the same density as liquid water (and would therefore neither sink nor float in water).

Co-author Professor Angelos Michaelides, from the University of Cambridge, said: “Water is the foundation of life but we still do not fully understand it. Amorphous ices may hold the key to explaining some of water’s many anomalies.”

Dr Davies said: “Ice is potentially a high-performance material in space. It could shield spacecraft from radiation or provide fuel in the form of hydrogen and oxygen. So we need to know about its various forms and properties.”

In one sentence, what does the mission you’re working on aim to do? 

Initially focusing on Jupiter’s interior, atmosphere and aurora, [Juno] has expanded during its extended mission to be a full system explorer capable of investigating the Galilean satellites, rings, inner moons, radiation belts, and boundaries of Jupiter’s magnetosphere.

What potential discoveries are at stake if Juno is defunded or cancelled?

Juno provides a unique opportunity to investigate previously unexplored regions of the Jovian system. Its next phase includes close flybys of the moons Thebe, Amalthea, Adrastea, and Metis. In addition to scientific exploration, Juno is providing critical new information directly relevant to national security by teaching us how space systems can survive and even reverse degradation from exposure to intense radiation.

How does Juno fit into NASA’s overall mission?

In addition to helping to lay a foundation for NASA’s Europa Clipper and ESA’s Jupiter Icy Moons Explorer (JUICE) missions enroute to Jupiter, Juno is providing the basis of understanding to compare the characteristics of Jupiter with the other giant planets in the Solar System: Saturn, Uranus and Neptune. This is vital for our understanding of Solar System formation and evolution, and for understanding planetary systems throughout the galaxy.

Why should this mission matter to people?

Continuing NASA’s Juno mission is a strategic investment in planetary science, offering continued insights into the Jupiter system and informing future exploration missions. The mission’s unique capabilities, cost-effectiveness, and alignment with strategic priorities make it an invaluable asset to the scientific community and the nation’s space exploration goals.

How many people are on your team?

There are about 200 people working on Juno, mostly part time.

How many states are represented by the Juno team?

10 states.

New Yorkers may not think of Sotheby’s, the tony auction house on the Upper East Side, as a place to casually pop in to, let alone a place to see dinosaurs or Martian meteorites.

But during “Geek Week,” that’s exactly what’s on free public view. From July 8 to 15, Sotheby’s is displaying some remarkable objects of natural history, science and space exploration before they hit the auction block.

This year’s standout is a six-foot-tall, 10-foot-long juvenile Ceratosaurus, one of only four known specimens of this extremely rare Jurassic dinosaur.

The roughly 150 million-year-old fossil, which has been reconstructed with a few ceramic elements to replace missing pieces, was discovered in Wyoming in 1996, according to Cassandra Hatton, Sotheby’s vice chairman of science and natural history.

It’s expected to sell for between 4 and 6 million dollars.

The sale includes more than 100 ancient items, sourced from various collectors, including dinosaur skulls and claws, chunks of meteorites, a 4,000-year-old stone axe and astonishing, iridescent slices of mineral and crystal, all on view.

Another showstopper is a 54-pound Martian meteorite – the largest known piece of Mars on Earth. This chunk of the Red Planet is believed to have been chipped off by one of only 16 known asteroid strikes powerful enough to launch debris into space, before landing in the Sahara desert.

“That chunk had to be loose enough to break off, and then it had to get on the right trajectory to travel 140 million miles to Earth, and then it had to land in a spot where someone could find it,” Hatton said. “And then we were lucky enough that someone came by who knew enough about meteorites to recognize that it wasn’t just a big rock.”

Hatton said scientists were able to confirm the meteorite’s extraterrestrial origin by extracting gas trapped in bubbles inside the rock and comparing it to Martian atmospheric data transmitted from NASA’s Viking lander in 1976.

The sale also includes objects that went to space with astronaut Buzz Aldrin, from his collection.

Another highlight includes what Hatton describes as the finest operational Apple-1 computer in existence: one of 50 machines hand-built by Steve Wozniak and Steve Jobs in 1976.

The Apple founders had built a few prototypes and were shopping them around town, Hatton said, when a local shopkeeper happened to see their presentation at the Home Brew Computer Club, an early computer hobbyist group in Menlo Park, California. He asked for 50, which sent the techies scrambling for parts to fulfill a bigger order than they’d anticipated.

The sale also includes one of Jobs’ earliest business cards, expected to sell for $5,000 to 8,000.

For those who associate Sotheby’s with high-stakes blue-chip art sales and exclusivity, Geek Week is a reminder that the auction house doubles as a pop-up museum.

Hatton said she’s the only science specialist on staff.

“I go from scientific books and manuscripts to tech, dinosaurs, minerals, meteorites, space exploration,” Hatton said. “I do hip-hop sales sometimes too. It all connects together somehow, in my mind.”

Sotheby’s Geek Week is at 1334 York Ave. from July 8 through 15, open from 10 a.m. to 5 p.m. every day except Sunday, when it opens at 1 p.m. No RSVP is required.

A riotous expanse of gas, dust, and stars stake out the dazzling territory of a duo of star clusters in this combined image from NASA’s Hubble and Webb space telescopes.

Open clusters NGC 460 and NGC 456 reside in the Small Magellanic Cloud, a dwarf galaxy orbiting the Milky Way. Open clusters consist of anywhere from a few dozen to a few thousand young stars loosely bound together by gravity. These particular clusters are part of an extensive complex of star clusters and nebulae that are likely linked to one another. As clouds of gas collapse, stars are born. These young, hot stars expel intense stellar winds that shape the nebulae around them, carving out the clouds and triggering other collapses, which in turn give rise to more stars.

In these images, Hubble’s view captures the glowing, ionized gas as stellar radiation blows “bubbles” in the clouds of gas and dust (blue), while Webb’s infrared vision highlights the clumps and delicate filamentary structures of dust (red). In Hubble images, dust is often seen silhouetted against and blocking light, but in Webb’s view, the dust – warmed by starlight – shines with its own infrared glow. This mixture of gas and dust between the universe’s stars is known as the interstellar medium.

The nodules visible in these images are scenes of active star formation, with stars ranging from just one to 10 million years old. In contrast, our Sun is 4.5 billion years old. The region that holds these clusters, known as the N83-84-85 complex, is home to multiple, rare O-type stars, hot and extremely massive stars that burn hydrogen like our Sun. Astronomers estimate there are only around 20,000 O-type stars among the approximately 400 billion stars in the Milky Way.

The Small Magellanic Cloud is of great interest to researchers because it is less enriched in metals than the Milky Way. Astronomers call all elements heavier than hydrogen and helium – that is, with more than two protons in the atom’s nucleus – “metals.”  This state mimics conditions in the early universe, so the Small Magellanic Cloud provides a relatively nearby laboratory to explore theories about star formation and the interstellar medium at early stages of cosmic history. With these observations of NGC 460 and NGC 456, researchers intend to study how gas flows in the region converge or divide; refine the collision history between the Small Magellanic Cloud and its fellow dwarf galaxy, the Large Magellanic Cloud; examine how bursts of star formation occur in such gravitational interactions between galaxies; and better understand the interstellar medium.

Explore More

Media Contact:

Claire Andreoli
NASA’s Goddard Space Flight Center, Greenbelt, MD
claire.andreoli@nasa.gov

Scientists have discovered hundreds of giant sand bodies beneath the North Sea that appear to defy fundamental geological principles and could have important implications for energy and carbon storage.

Using high-resolution 3D seismic (sound wave) imaging, combined with data and rock samples from hundreds of wells, researchers from The University of Manchester in collaboration with industry, identified vast mounds of sand—some several kilometers wide—that appear to have sunk downward, displacing older, lighter and softer materials from beneath them.

The result is stratigraphic inversion—a reversal of the usual geological order in which younger rocks are typically deposited on top of older ones—on a previously unseen scale.

While stratigraphic inversion has previously been observed at small scales, the structures discovered by the Manchester team, now named “sinkites,” are the largest example of the phenomenon documented so far.

The finding, published in the journal Communications Earth & Environment, challenges scientists understanding of the subsurface and could have implications for carbon storage.

“This discovery reveals a geological process we haven’t seen before on this scale,” said lead author Professor Mads Huuse from The University of Manchester. “What we’ve found are structures where dense sand has sunk into lighter sediments that floated to the top of the sand, effectively flipping the conventional layers we’d expect to see and creating huge mounds beneath the sea.”

It is believed the sinkites formed millions of years ago during the Late Miocene to Pliocene periods, when earthquakes or sudden shifts in underground pressure may have caused the sand to liquefy and sink downward through natural fractures in the seabed. This displaced the underlying, more porous but rigid, ooze rafts—composed largely of microscopic marine fossils—bound by shrinkage cracks, sending them floating upwards. The researchers have dubbed these lighter, uplifted features “floatites.”

The finding could help scientists better predict where oil and gas might be trapped and where it’s safe to store carbon dioxide underground.

“This research shows how fluids and sediments can move around in the Earth’s crust in unexpected ways. Understanding how these sinkites formed could significantly change how we assess underground reservoirs, sealing, and fluid migration—all of which are vital for carbon capture and storage,” said Huuse. 

Now the team are busy documenting other examples of this process and assessing how exactly it impacts our understanding of subsurface reservoirs and sealing intervals.

Researchers have found clouds of cold gas embedded deep within larger, superheated gas clouds – or Fermi bubbles – at the Milky Way’s center. The finding challenges current models of Fermi bubble formation and reveals that the bubbles are much younger than previously estimated.

“The Fermi bubbles are enormous structures of hot gas that extend above and below the disk of the Milky Way, reaching about 25,000 light years in each direction from the galaxy’s center – spanning a total height of 50,000 light years,” says Rongmon Bordoloi, associate professor of physics at North Carolina State University and corresponding author of the research.

“Fermi bubbles are a relatively recent discovery – they were first identified by telescopes that ‘see’ gamma rays in 2010 – there are different theories about how it happened, but we do know that it was an extremely sudden and violent event, like a volcanic eruption but on a massive scale.”

Bordoloi and the research team used the U.S. National Science Foundation Green Bank Telescope (NSF GBT) to observe the Fermi bubbles and get high resolution data about the composition of the gas within and the speed at which it is moving. These measurements were twice as sensitive as previous radio telescope surveys of the Fermi bubbles and allowed them to observe finer detail within the bubbles.

Most of the gas inside the Fermi bubbles is around 1 million degrees Kelvin. However, the research team also found something surprising: dense clouds of neutral hydrogen gas, each one measuring several thousand solar masses, dotted within the bubbles 12,000 light years above the center of the Milky Way.

“These clouds of neutral hydrogen are cold, relative to the rest of the Fermi bubble,” says Andrew Fox, ESA-AURA Astronomer at the Space Telescope Science Institute and coauthor of the paper.

“They’re around 10,000 degrees Kelvin, so cooler than their surroundings by at least a factor of 100. Finding those clouds within the Fermi bubble is like finding ice cubes in a volcano.”

Their existence is surprising because the hot (over 1 million degrees Kelvin), high-velocity environment of the nuclear outflow should have rapidly destroyed any cooler gas.

“Computer models of cool gas interacting with hot outflowing gas in extreme environments like the Fermi bubbles show that cool clouds should be rapidly destroyed, usually within a few million years, a timescale that aligns with independent estimates of the Fermi bubbles’ age,” Bordoloi says. “It wouldn’t be possible for the clouds to be present at all if the Fermi bubbles were 10 million years old or older.

“What makes this discovery even more remarkable is its synergy with ultraviolet observations from the Hubble Space Telescope (HST),” Bordoloi says. “The clouds lie along a sightline previously observed with HST, which detected highly ionized multiphase gas, ranging in temperatures from a million to 100,000 Kelvin – which is what you’d expect to see if a cold gas is getting evaporated.”

The team was also able to calculate the speed at which the gases are moving, which further confirmed the age.

“These gases are moving around a million miles per hour, which also marks the Fermi bubbles as a recent development,” Bordoloi says. “These clouds weren’t here when dinosaurs roamed Earth. In cosmic time scales, a million years is the blink of an eye.”

“We believe that these cold clouds were swept up from the Milky Way’s center and carried aloft by the very hot wind that formed the Fermi bubbles,” says Jay Lockman, an astronomer at the Green Bank Observatory and coauthor of the paper. “Just as you can’t see the motion of the wind on Earth unless there are clouds to track it, we can’t see the hot wind from the Milky Way but can detect radio emission from the cold clouds it carries along.”

This discovery challenges current understanding of how cold clouds can survive the extreme energetic environment of the Galactic Center, placing strong empirical constraints on how outflows interact with their surroundings. The findings provide a crucial benchmark for simulations of galactic feedback and evolution, reshaping our view of how energy and matter cycle through galaxies.

The work appears in Astrophysical Journal Letters and is supported by the National Science Foundation under grant number AST-2206853.

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University of Sydney researchers have harnessed human-made lightning to develop a more efficient method of generating ammonia.

The current method to generate ammonia, the Haber-Bosch process, comes at great climate cost, leaving a huge carbon footprint. It also needs to happen on a large scale and close to sources of cheap natural gas to make it cost effective.

Lead researcher Professor PJ Cullen from the University of Sydney’s School of Chemical and Biomolecular Engineering and the Net Zero Institute, said industry’s appetite for ammonia is only growing.

“For the past decade, the global scientific community, including our lab, wants to uncover a more sustainable way to produce ammonia that doesn’t rely on fossil fuels,” he said.

“Currently, generating ammonia requires centralised production and long-distance transportation of the product. We need a low-cost, decentralised and scalable green ammonia.”

The research is the culmination of six years’ work.

“In this research we’ve successfully developed a method that allows air to be converted to ammonia in its gaseous form using electricity,” he said.

Professor Cullen’s team’s new method to generate ammonia works by harnessing the power of plasma, by electrifying or exciting the air.

But the star is a membrane-based electrolyser, a seemingly non-descript silver box, where the conversion to gaseous ammonia happens.

During the Haber-Bosch process, ammonia is made by combining nitrogen and hydrogen gases under high temperatures and pressure in the presence of catalyst.

The plasma-based method Professor Cullen’s team developed uses electricity to excite nitrogen and oxygen molecules in the air. The team then passes these molecules to the membrane-based electrolyser to convert them to ammonia.

Professor Cullen said the findings signal a new phase in making green ammonia possible and his team is now working on making the method more energy efficient and competitive compared to the Haber-Bosch process.

“This new approach is a two-step process, namely combining plasma and electrolysis. We have already made the plasma component viable in terms of energy efficiency and scalability,” he said.

“To create a more complete solution to a sustainable ammonia productive, we need to push the energy efficiency of the electrolyser component.”

Earth is expected to spin more quickly in the coming weeks, making some of our days unusually short. On July 9, July 22 and Aug. 5, the position of the moon is expected to affect Earth’s rotation so that each day is between 1.3 and 1.51 milliseconds shorter than normal.

A day on Earth is the length of time needed for our planet to fully rotate on its axis — approximately 86,400 seconds, or 24 hours. But Earth’s rotation is affected by a number of things, including the positions of the sun and moon, changes to Earth’s magnetic field, and the balance of mass on the planet.

NASA’s Lucy mission is key to helping us understand the early history of our solar system as it studies asteroids like the Donaldjohanson.

What is it?

Named after the paleoanthropologist who co-discovered the Lucy skeleton, NASA’s Lucy space probe is key to helping scientists understand the early history of our solar system. Launched on Oct. 16, 2021, Lucy is the first space mission designed specifically to study Trojan asteroids, which are ancient remnants from the early solar system that share orbits with the sun and Jupiter.