Category: 7. Science

Abell 209 is a massive galaxy cluster located about 2.8 billion light-years away in the constellation of Cetus.

Galaxy clusters contain thousands of galaxies of all ages, shapes and sizes.

Typically, they have a mass of about one million billion times the mass of the Sun.

At one point in time galaxy clusters were believed to be the largest structures in the Universe — until they were usurped in the 1980s by the discovery of superclusters, which typically contain dozens of galaxy clusters and groups and span hundreds of millions of light-years.

However, galaxy clusters do have one thing to cling on to; superclusters are not held together by gravity, so galaxy clusters still retain the title of the biggest structures in the Universe bound by gravity.

“Abell 209’s galaxies are separated by millions of light-years, and the seemingly empty space between the galaxies is actually filled with hot, diffuse gas that can be spotted only at X-ray wavelengths,” Hubble astronomers said in a statement.

“An even more elusive occupant of this galaxy cluster is dark matter: a form of matter that does not interact with light.”

“The Universe is understood to be comprised of 5% normal matter, 25% dark matter, and 70% dark energy,” they said.

“Hubble observations like the ones used to create this image can help us answer fundamental questions about our Universe, including mysteries surrounding dark matter and dark energy.”

“These investigations leverage the immense mass of a galaxy cluster, which can bend the fabric of spacetime itself and create warped and magnified images of background galaxies and stars in a process called gravitational lensing.”

“While this image lacks the dramatic rings that gravitational lensing can sometimes create, Abell 209 still shows subtle signs of lensing at work, in the form of streaky, slightly curved galaxies within the cluster’s golden glow.”

“By measuring the distortion of these galaxies, astronomers can map the distribution of mass within the cluster, illuminating the underlying cloud of dark matter.”

“This information, which Hubble’s fine resolution and sensitive instruments help to provide, is critical for testing theories of how our Universe has evolved.”

Astroboffins have found the first evidence of a double-detonated Type Ia supernova, which could explain why we have enough bright points of reference in the skies to plot our place in the universe.

Data from the European Southern Observatory’s Very Large Telescope (VLT) on SNR 0509-67.5 – a supernova 160,000 light-years from Earth, caused when a white dwarf star hit critical mass and exploded – reveals that the elements created suggest something may have triggered the star to explode ahead of time.

Supernovae like these are very luminous and referred to as “standard candles” in astronomy. As fixed points, they are used to measure the expansion of the universe, but there are a lot more of them than current theories would predict, and new data could explain why.

“The explosions of white dwarfs play a crucial role in astronomy,” said Priyam Das, a PhD student at the University of New South Wales Canberra, Australia, who led the study on SNR 0509-67.5 published [PDF] in Nature Astronomy. “Yet, despite their importance, the long-standing puzzle of the exact mechanism triggering their explosion remains unsolved.”

Type Ia explosions are thought to be caused when two white dwarf stars orbit closely and one accretes mass from another and grows to about 1.4 times the mass of our Sun. This is the Chandrasekhar limit, named after Nobel Prize-winning physicist Subrahmanyan Chandrasekhar, or the maximum mass of a stable white dwarf star. However, spectrographic data from the VLT shows signatures indicating the white dwarf could have detonated earlier due to an elemental collision.

If a white dwarf collects enough helium, the second most abundant element in the universe, this can form a shell around the star and ignite, compressing it and causing an early eruption before the Chandrasekhar limit is reached. That could explain why we have so many points of reference.

SNR 0509-67.5, a bright spot in the universe. Source: ESO

“The classical ‘textbook’ wisdom of how Type Ia supernovae explode is that material is accreted onto a white dwarf star composed of carbon and oxygen,” Professor Friedrich Röpke at the Center for Astronomy of Ruprecht-Karls University told The Register.

“It seems very difficult to grow a white dwarf star to the Chandrasekhar mass. Since these objects are very stable, a drastic event is needed for this. One scenario that was considered to be likely working is the double detonation, where the detonation in the helium shell surrounding the carbon-oxygen white dwarf star triggers the actual detonation of that star.”

The elements we’re made of were formed in exploding stars, and Type Ia supernovae typically eject large amounts of iron. But what the VLT saw was expanding shells of more complex elements such as calcium and sulfur, suggesting the double-detonation idea is correct.

“We are for the first time able to provide direct observational support for this (before only hypothetical) scenario,” Professor Röpke explained.

“We see two shells of heavy elements that are produced by two subsequent and spatially separated detonations. Calcium is one of these elements and it can be observed well with our methods. So, it is a tracer of the double detonation structure, but similar double shell structures are also expected in other heavy elements produced in the detonations.” ®

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.

Hubble (ACS)

Webb (NIRCAM)

Hubble (ACS)Webb (NIRCAM)

Hubble and Webb view a duo of open star clusters

Image Details

Slide to switch between Hubble and Web images. Hubble’s view captures visible light and some infrared wavelengths, while Webb’s view is exclusively infrared. The nebulae’s glowing gas, ionized by the radiation of nearby stars, is distinct in Hubble’s view. Dusty areas that appear dark in the Hubble image are visible as bright structures in the Webb image, and more background galaxies are visible since infrared light from fainter and farther galaxies can pass through the obscuring clouds of gas and dust.

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.

“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.

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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.