Universe Today

Some Supermassive Black Holes (SMBHs) consume vast quantities of gas and dust, triggering brilliant light shows that can outshine an entire galaxy. But others are much more sedate, emitting faint but steady light from their home in the heart of their galaxy.

Observations from the now-retired Spitzer Space Telescope help show why that is.

It appears that every large galaxy has an SMBH at its heart. This is true of our Milky Way galaxy and of our closest galactic neighbour, Andromeda (M31.) Like all black holes, SMBHs draw material towards them that gathers in an accretion disk. As the material in the disk rotates and heats up, it emits light before it falls into the hole.

It turns out that both of those SMBHs are among the quiet eaters in the black hole population. Others are much more ravenous, consuming large amounts of matter in clumps and shining brightly for periods of time. Astrophysicists wonder what’s behind the difference.

Recent research published in The Astrophysical Journal has determined what’s happening in these different black holes. The title is “The Accretion Mode in Sub-Eddington Supermassive Black Holes: Getting into the Central Parsecs of Andromeda.” The lead author is Christian Alig, a post-doc student at the Max Planck Institute for Extraterrestrial Physics.

Andromeda (M31) is a close neighbour in cosmic terms. It’s about 780 kiloparsecs away, or about 2.5 million light years. It’s a sub-Eddington SMBH, meaning that it hasn’t reached the theoretical maximum accretion rate. Its proximity makes it an excellent target for observing and studying large-scale galactic structure, especially the nucleus. The nucleus is where most of the action is, dominated by an SMBH and containing a dense population of stars and a network of gas and dust. This research focuses on the gas and dust.

“This paper investigates the formation, stability, and role of the network of dust/gas filaments surrounding the M31 nucleus,” the authors write in their research. “The proximity of M31, 780 kpc, allows us to visualize in great detail the morphology, size, and kinematics of the filaments in ionized gas and dust.”

The researchers worked with images from the Hubble and Spitzer Space Telescopes. Using different filters, the telescope images revealed the shape and other characteristics of the network of gas and dust. “The appearance of the central region of M31 varies dramatically in the different mid-infrared bands, from a smooth, featureless bulge dominated by the old stellar population at 3.6 ?m to the distinct spiral dust filament structure that dominates the 8 ?m image,” the authors explain.

These images from the research show how different telescopes and filters can work together to reveal structure. The top row is Spitzer images of M31 at different wavelengths. Structure emerges successively with each image. The bottom right image is the 8 ?m image minus the 4.5 ?m image, which basically removes starlight. The middle right bottom image is a Hubble image showing H-alpha and ionized nitrogen. The bottom left image is a Hubble UV image, and the middle left is the same image with starlight removed. Image Credit: Alig et al. 2024.

The researchers found a circumnuclear dust ring around the galactic nucleus that measures between 0.5 and 1 kpc from the center (1,630 to 3,260 light-years.) Filaments of dust emanate from this ring, forming a spiral inside it. “Inside the ring, the dust filaments follow circularized orbits around the center, ending in a nuclear spiral in the central hundred parsecs,” the authors explain.

These images from the research successive zoom-ins at different wavelengths. In the middle image, a dotted white line outlines the circumnuclear ring in M31. The third image “… is a pure dust map of the central kiloparsec of M31,” the authors write. In the third image, an arrow shows the filament used as a reference in simulations. Image Credit: Alig et al. 2024.

After identifying structures in the telescope images, the researchers turned to simulations. They used hydrodynamical simulations to see what initial conditions made filaments and streamers of flowing gas move nearer to the SMBH. “By predicting the orbit and velocity of the filaments, we aim to infer the role of the nuclear spiral as a feeder of the M31 BH,” they explain.

The hydrodynamical simulations cover a wide area of the nucleus, from 900 parsecs to 6 parsecs from the SMBH in M31. The starting point for the simulations is the brightest and longest dust filament the team found in the images. In the image above, it’s marked with a white arrow. “The filament curves progressively toward the center as it approaches,” the researchers write. “It is also seen in the ionized gas <H-alpha and NII> though more diffuse, in the central few hundred parsecs.”

The simulations assume that the dust filament is made of dust infalling from the circumnuclear ring, though the researchers didn’t investigate how the dust made its way into the ring in the first place. The simulation began by injecting gas into the ring. The team let the simulation fun for millions of years to see how the gas behaves. “In the end, we needed about 200 Myr of simulation time to arrive at a configuration that best reproduces the observations,” the authors explain.

This figure shows snapshots from the simulation at different intervals from 17.5 million years to 156 million years. (a) and (b) don’t deviate much from an N-body simulation, but eventually, a ring takes shape. In (b,) the freshly injected material collides with the uppermost arc. That heats up the gas, creating a hot surrounding atmosphere shown in blue/pink. The stream crosses itself repeatedly after that and experiences friction from the atmosphere. (d) through (f) shows how the gas eventually circularizes into a ring shape. Image Credit: Alig et al. 2024.

“Friction at the inner edge of an elongated ring structure that forms in (e) causes thin filaments to spiral inward, eventually forming a small disk in the inner 100 pc, visible in (f),” the authors explain.

All of the team’s simulations arrived at similar results, even though they began with different parameters like initial angles, velocities, distances, and angle of injection. “Interestingly, due to the relatively good radial symmetry of the M31 potential in the inner 1 kpc, all simulations lead to very similar results,” the researchers explain.

The observations and images of M31’s inner region are in line with what astronomers find in other quiet galaxies. Those surveys “… reveal a common pattern in the dust morphology, formed by narrow, long dust filaments ending in a spiral in the central few hundred parsecs,” the authors write. The majority of low-luminosity galaxies in a 2003 study also have nuclear spirals that span several hundred parsecs.

Interestingly, high-accreting galaxies different than M31 also show a network of dust lanes and filaments, but their morphology is less organized. It often consists of one long filament that runs right across the nucleus. This could be the critical difference between the sedate SMBH in M31 and galaxies with much brighter black holes.

M31 and its ilk are fed a slow, steady diet of gas, which means their brightness is steady. But other galaxies are fed matter in larger clumps, which makes their brightness reach brilliant peaks, outshining all the stars in their galaxy. That’s the difference between gluttonous SMBHs and well-behaved ones.

“The hydrodynamical simulations show that the role of these filaments <in M31> is to transport matter to the center; however, the net amount that they transport to the center is small—a consequence of their extensive interaction with themselves, their surrounding atmosphere, and the ISM over a timescale of several million years,” the authors conclude. “We postulate that when dust/gas filaments in the central hundred parsecs of galaxies get to settle in a nuclear spiral configuration, a low accretion mode of the central BH will result.”

So galaxies with spiral patterns of gas in their nuclei have low accretion modes and lower, steadier luminosity. Galaxies without these patterns accrete more matter irregularly, and their luminosity surges.

One of the interesting things about this research is that it didn’t rely on new observations from new, powerful telescopes like the JWST. Instead, it relied on images from NASA’s Spitzer Space Telescope, which ended its mission in January 2020. It illustrates how modern telescopes and observatories generate massive amounts of data that scientists can utilize in different ways long after the telescope’s mission has ended.

“This is a great example of scientists reexamining archival data to reveal more about galaxy dynamics by comparing it to the latest computer simulations,” said study co-author Almudena Prieto, an astrophysicist at the Institute of Astrophysics of the Canary Islands and the University Observatory Munich. “We have 20-year-old data telling us things we didn’t recognize in it when we first collected it.”

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A long time ago, in two galaxies far, far away, two massive black holes merged. This happened when the Universe was only 740 million years old. A team of astronomers used JWST to study this event, the most distant (and earliest) detection of a black hole merger ever.

Such collisions are fairly commonplace in more modern epochs of cosmic history and astronomers know that they lead to ever-more massive black holes in the centers of galaxies. The resulting supermassive black holes can contain millions of billions of solar masses. They affect the evolution of their galaxies in many ways.

Using JWST and HST, astronomers have found behemoth black holes earlier and earlier in cosmic time, within the first billion years of the Universe’s history. That raises the question: how did they get so massive so fast? Black holes accrete matter as they grow, and for the most supermassive ones, their colliding galaxies are part of that matter-harvesting history.

What JWST Shows Us about Early Black Holes Merging

The most recent JWST observations focused on a system called ZS7. It’s a galaxy merger where two very early systems come together, complete with colliding black holes. This is not something astronomers can detect with ground-based telescopes. The merger itself lies quite far away. Plus, the expansion of the Universe stretches its light into the infrared part of the electromagnetic spectrum. That makes it inaccessible from Earth’s surface. However, infrared is detectable with JWST’s Near-infrared Spectrometer (NIRSpec). It can find signatures of mergers in the early Universe, according to astronomer Hannah Übler of the University of Cambridge in the United Kingdom.

Zeroing in on the ZS7 galaxy system and the colliding black holes. Courtesy: The field in which the ZS7 galaxy merger was observed by JWST. Courtesy ESA/Webb, NASA, CSA, J. Dunlop, D. Magee, P. G. Pérez-González, H. Übler, R. Maiolino, et. al

“We found evidence for very dense gas with fast motions in the vicinity of the black hole, as well as hot and highly ionized gas illuminated by the energetic radiation typically produced by black holes in their accretion episodes,” said Übler, who is lead author on a paper about the discovery. “Thanks to the unprecedented sharpness of its imaging capabilities, Webb also allowed our team to spatially separate the two black holes.”

Those black holes are pretty massive: one contains about 50 million solar masses. The other probably has about the same mass, but it’s hard to tell because it’s embedded in a dense gas region. The stellar masses of the galaxies puts them in about the same stellar-mass population as the nearby Large Magellanic Cloud, according to astronomer Pablo G. Pérez-González of the Centro de Astrobiología (CAB), CSIC/INTA, in Spain. “We can try to imagine how the evolution of merging galaxies could be affected if each galaxy had one supermassive black hole as large or larger than the one we have in the Milky Way”.

Other Implications of Black Hole Mergers at Cosmic Dawn

The analysis of the JWST observations reinforces the idea that mergers are an important way for black holes to grow. That’s particularly true in the early Universe, according to Ühler. “Together with other Webb findings of active, massive black holes in the distant Universe, our results also show that massive black holes have been shaping the evolution of galaxies from the very beginning.”

Many active galactic nuclei (AGN) in the very early Universe are associated with somewhat massive black holes. These are likely part of a general merger process in early epochs. Astronomers want to know when these mergers began. That would help them pinpoint the growth of the central supermassive black holes. Mergers of that kind are a likely route for the growth of black holes so early in cosmic time.

An artist’s impression of two merging black holes. Image: NASA/CXC/A. Hobart

That’s why astronomers are so anxious to spot them with JWST and future telescopes. They hold the key to understanding the evolution of galaxies and black holes in the infancy of the Universe. Uhler and her team members point this out in their paper, saying: “Our results seem to support a scenario of an imminent massive black hole merger in the early universe, highlighting this as an additional important channel for the early growth of black holes. Together with other recent findings in the literature, this suggests that massive black hole merging in the distant universe is common.”

Of course, these mergers don’t just generate light we can detect with JWST. They also generate very faint gravitational waves. But, there’s hope of detecting those waves with the upcoming Laser Interferometer Space Antenna (LISA). It will be in place in the 2030s and should be able to focus on the types of galaxy and black-hole mergers JWST is detecting today in infrared light.

For More Information

Webb Detects Most Distant Black Hole Merger to Date
GA-NIFS: JWST Discovers an Offset AGN 740 Million Years After the Big Bang

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The Sun has been vying for attention these last couple of weeks. First with the appearance of a fabulous complex sunspot region and then with a plethora of solar flares. On the 14th May, yet another was released, this time an X8.7 class flare from the same complex sunspot regions. It was significantly more powerful than the flare that set off the aurora displays which enchanted much of the planet but alas it was not pointing toward the Earth (

Europa has always held a fascination to me. I think it’s the concept of a world with a sub-surface ocean and the possibility of life that has inspired me and many others. In September 2022, NASAs Juno spacecraft made a flyby, coming within 355 kilometres of the surface. Since the encounter, scientists have been exploring the images and have identified regions where brine may have bubbled to the surface. Other images revealed possible, previously unidentified steep-walled depressions up to 50km wide, this could be caused by a free-floating ocean! 

Juno was launched to Jupiter on 5 August 2011. It took off from the Cape Canaveral site on board an Atlas V rocket and travelled around 3 billion kilometres. It arrived at Jupiter on 4 July 2016 and in September 2022 made its closest flyby of Europa. The frozen world is the second of the four Galilean satellites that were discovered by Galileo over 400 years ago. Visible in small telescopes, the true nature of the moon is only detectable by visiting craft like Juno. 

Artist’s impression of NASA’s Galileo space probe in orbit of Jupiter. Credit: NASA

During its close fly-by, one of the onboard cameras known as Juno-Cam took the highest resolution images of the moon since Galileo took a flyby in 2000. The images supported the long held theory that the icy crusts at the north and south poles are not where they used to be. Another instrument on board, known as the Stellar Reference Unit (SRU), revealed possible activity resembling plumes where brine may have bubbled to the surface. 

The ground track over Europa that was followed by Juno enabled imaging around the equatorial regions. The images revealed the usual, expected blocks of ice, walls, ridges and scarps but also found something else. Steep walled depressions that measured 20 to 50 kilometres across were also seen and they resembled large ovoid pits. 

One of Juno’s enormous solar panels, unfurled on Earth. NASA/JPL. SWrI

The observations of the meanderings of the north/south polar ice and the varied surface features all point towards an outer icy shell that is free-floating upon the sub surface ocean.  This can only happen if the outer shell is not connected to the rocky interior. When this happens, there are high levels of stress on the ice which then causes the fracture pattern witnessed. The images represent the first time such patterns have been seen in the southern hemisphere, the first evidence of true polar wandering. 

The images from the SRU surprisingly provided the best quality images. It was originally designed to detect faint light from stars for navigation. Instead, the team used it to capture images when Europa was illuminated by the gentle glow of sunlight reflected from Jupiter. It was quite a novel approach and allowed complex features to become far more pronounced than before. Intricate networks of ridges criss-crossing the surface were identified along with dark stains from water plumes. One feature in particular stood out, nicknamed ‘the Platypus’, it was a 37 kilometre by 67 kilometre region shaped somewhat like a platypus. 

Source : NASA’s Juno Provides High-Definition Views of Europa’s Icy Shell

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The tension between quantum mechanics and relativity has long been a central split in modern-day physics. Developing a theory of quantum gravity remains one of the great outstanding challenges of the discipline. And yet, no one has yet been able to do it. But as we collect more data, it shines more light on the potential solution, even if some of that data happens to show negative results.

That happened recently with a review of data collected at IceCube, a neutrino detector located in the Antarctic ice sheet, and compiled by researchers at the University of Texas at Arlington. They looked for signs that gravity could vary even a minuscule amount based on quantum mechanical fluctuations. And, to put it bluntly, they didn’t find any evidence of that happening.

To check for these minuscule fluctuations, they analyzed more than 300,000 detected neutrinos that IceCube had captured. IceCube is an impressive engineering feat, with thousands of sensors buried over one sq km in the ice. When one of the detectors is triggered by one of a hundred trillions of neutrinos passing through it every second, data on whether it was affected by any perturbations in the local gravity of that area can be collected.

Fraser discusses the neutrino detectors of IceCube.

Such massive data sets allowed for a very accurate reading—”over a million times more [accurate],” according to Dr. Benjamin Jones, one of over 300 physicists who worked on a paper detailing IceCube’s findings, which he described in a press release from the University of Texas at Arlington. Despite that, the researchers were still unable to find any evidence for those quantum fluctuations in the local gravitational field.

That’s not all bad news, though. Eliminating one possible explanation for quantum gravity could lead to work on others. Dr. Jones sees that prospect as he describes how his lab’s efforts are shifting to studying the mass of neutrinos themselves. Understanding more about these elusive particles certainly won’t hurt efforts to understand the overall physical model of the universe. Still, many scientists are likely disappointed by this newest failure to find a potential lead in the solution to a “theory of everything.”

For now, IceCube will keep collecting data, and scientists will continue to analyze it. But efforts to find a new theory of quantum gravity seem to be back at the theoretical drawing—which is a necessary step before they can be tested, no matter how fancy the detector itself is.

PBS Spacetime explains the idea behind quantum gravity.

Learn More:
UTA – UTA SCIENTISTS TEST FOR QUANTUM NATURE OF GRAVITY
IceCube Collaboration – Search for decoherence from quantum gravity with atmospheric neutrinos
UT – Scientists are Recommending IceCube Should be Eight Times Bigger
UT – IceCube Makes a Neutrino Map of the Milky Way

Lead Image:
IceCube Lab under the stars in the Antarctic.
Credit – IceCube/NSF

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NASA’s Juno spacecraft spies a tiny inner moon of Jupiter, Amalthea.

It’s tiny, but it’s there. By now, we’re all used to seeing amazing photos of Jupiter courtesy of NASA’s Juno mission on a routine basis. Many of these are processed by volunteer ‘citizen scientists,’ and they show the swirling cloud-tops of Jove courtesy of the spacecraft’s JunoCam in stunning detail.

Recently, JunoCam captured something special. Look closely at the side-by-side images of Jupiter from March 7th, 2024, and you’ll see a tiny speck transiting the Great Red Spot in the left lead image, that isn’t in the right. That’s the tiny inner moon Amalthea, just 84 kilometers across. The image was captured during the 59th perijove (close flyby) of the ‘King of the Planets,’ at a range of 265,000 kilometers distant (about two-thirds of the Earth-Moon distance).

Amalthea (arrowed) transits Jupiter. Credit: NASA/JPL-Caltech/SwRI/MSSS. Image processing by Gerald Eichstädt. Amalthea: An Origin Story

The elusive moon was discovered by prolific astronomer and observer E.E. Barnard on the night of September 9th, 1892. Barnard used the 91-centimeter diameter refractor telescope at the Lick observatory to spot the +14th magnitude moon, which never strays more than 30” from Jupiter (less than the apparent diameter of the planet) on its 12 hour orbit. Amalthea holds the distinction of being the last moon discovered via direct visual observation, and the first moon of Jupiter discovered since Galileo first spotted the four major Galilean moons in 1610. Today, Jupiter has 95 known moons, mostly captured asteroids. These were mainly discovered photographically and during spacecraft flybys.

One of Juno’s enormous solar panels, unfurled on Earth. NASA/JPL/SWrI

Like other small moonlets, Amalthea isn’t big enough to pull itself into a true sphere. Instead, like the Martian moons Phobos and Deimos, Amalthea is a potato-shaped, captured asteroid.

Amalthea: None More Red

The moon is also the reddest object in the solar system, and no doubt undergoes some serious tidal flexing thanks to the enormous gravitational field of nearby Jove. Amalthea is located 180,000 kilometers from Jove, just a little over 100,000 kilometers outside of Jupiter’s Roche limit radius. Any closer to Jove would tear Amalthea apart. The very innermost moon Metis just skims this limit.

Voyager 1’s color image of Amalthea from 1979. Credit: NASA/JPL

Voyagers 1 and 2 gave us the first blurry views of the moon. NASA’s only other Jupiter orbiter Galileo has provided us with the best images of Amalthea to date, with a flyby 374,000 kilometers distant on November 26, 1999. Those images reveal a misshapen world, not unlike Mars’ moon Deimos. From the surface of Amalthea, Jupiter would provide an amazing sight, spanning nearly half the sky at 42 degrees across.

The Galileo spacecraft’s best view of Amalthea. Credit: NASA/JPL Juno and the Present Status of the Mission

Juno launched from the Cape on August 5th, 2011, and arrived at Jupiter on July 5th, 2016. The mission probes the interior of Jupiter and its magnetic and radiation environment. Juno will answer key questions, including whether the planet has a solid core. Juno is the first solar-powered (as opposed to nuclear/plutonium-fueled) mission to the outer planets, meaning its nominal wide-ranging orbit was meant to avoid radiation damage to the solar panels. Engineers only allowed the spacecraft to venture in past the inner moons of Jupiter during the extended and final phase of the mission. Juno will operate until at least September 2025.

Two more missions are headed to Jupiter; ESA’s JUICE (Jupiter Icy moons Explorer) launched on April 14th 2023, and NASA’s Europa Clipper, set to launch in October 2024.

Jupiter, as seen from the surface of Amalthea. Credit: Stellarium

Watch for more amazing images courtesy of Juno, as the mission enters its final months and days.

The post New Photos Show Jupiter’s Tiny Moon Amalthea appeared first on Universe Today.

Despite the vast distance between us and Saturn’s gleaming moon Enceladus, the icy ocean moon is a prime target in our search for life. It vents water vapour and large organic molecules into space through fissures in its icy shell, which is relatively thin compared to other icy ocean moons like Jupiter’s Europa. Though still out of reach, scientific access to its ocean is not as challenging as on Europa, which has a much thicker ice shell.

The presence of large organic molecules isn’t very controversial. But they don’t necessarily signify that something alive lurks in its ancient, unseen ocean. Instead, hydrothermal processes could produce them. The complexity arises because hydrothermal processes are also linked to the emergence of life.

Understanding the abiotic processes that produce these molecules is important not just for Enceladus. It could serve as a baseline for understanding the results of a future mission to the frozen moon and any biosignatures it might detect.

New research in the journal Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences examines this issue. It’s titled “Laboratory characterization of hydrothermally processed oligopeptides in ice grains emitted by Enceladus and Europa.” The lead author is Dr. Nozair Khawaja from the Institute of Space Systems (IRS) at the University of Stuttgart.

Scientists postulate the life on Earth got started at hydrothermal events on the ocean floor. These vents provide mineral-rich fluids. At deep ocean vents under extreme pressure, these minerals can react with seawater to produce the building blocks of life.

This image shows a black smoker hydrothermal vent discovered in the Atlantic Ocean in 1979. It’s fueled from deep beneath the surface by magma that superheats the water, and the plume delivers minerals to the sea. Courtesy USGS.

“In research, we also speak of a hydrothermal field,” explains lead author Khawaja. “There is convincing evidence that conditions prevail in such fields that are important for the emergence or maintenance of simple life forms.”

Much of what we know about Enceladus comes from the Cassini mission. Scientists are still working with Cassini’s data even though it ended in 2017. Although much of the data was low resolution, it’s still valuable.

Professor Frank Postberg from the Freie Universität (FU) Berlin is one of the study’s co-authors. “In 2018 and 2019, we encountered various organic molecules, including some that are typically building blocks of biological compounds,” Postberg said. “And that means it is possible that chemical reactions are taking place there that could eventually lead to life.”

There’s a missing link between the hydrothermal vents and the molecules vented into space. Scientists aren’t certain if the vents are responsible for the molecules or in what way. Is life involved?

This image shows the detection of hydrothermally altered biosignatures on Enceladus. Image Credit: SWRI/NASA/JPL

To answer these questions, the researchers simulated an Enceladus hydrothermal vent in their laboratory.

“To this end, we simulated the parameters of a possible hydrothermal field on Enceladus in the laboratory at the FU Berlin,” said lead author Khawaja. “We then investigated what effects these conditions have on a simple chain of amino acids.” Amino acids are the basic building blocks of proteins and the basis of all Earth life. There are hundreds of them, and 22 of them are in all living cells. They’re the precursors to proteins and they show that life on Earth is all connected.

The researchers subjected amino acids to conditions thought to persist at Encledadus’ ocean floor. “Here, we present results from our newly established facility to simulate the processing of ocean material within the temperature range 80–150°C and the pressure range 80–130 bar, representing conditions suggested for the water-rock interface on Enceladus,” they write in their paper. Under those conditions, the chains of amino acids behaved characteristically.

But that’s in a lab. Can we devise a space probe that can detect these types of changes on Enceladus? The changes themselves are obscured, but do they produce byproducts or markers that are emitted into space?

Cassini’s Cosmic Dust Analyzer (CDA) detected the organic molecules in Enceladus’ plumes by watching collisions between rapidly moving particles that shatter molecules and vapourize their contents. Some particles, stripped of their electrons, become positively charged and are attracted to a negative electrode on the instrument. The less massive they are, the faster they reach the electrode.

By combining a large amount of this type of data, the CDA revealed a lot about the original molecules.

But this can’t be replicated in a lab.

“Instead, we employed an alternative measurement method called LILBID for the first time on ice particles containing hydrothermally altered material,” Khawaja explains. LILBID stands for laser-induced liquid beam ion desorption, a different type of mass spectrometry than the CDA performs. Though the method is different, it produces results similar to Cassini’s CDA instrument.

“This delivers very similar mass spectra to the Cassini instrument. We used this to measure an amino acid chain before and after the experiment. In the process, we came across characteristic signals that were caused by the reactions in our simulated hydrothermal field,” Khawaja said.

Specifically, the researchers examined the hydrothermal processing of the triglycine (GGG) peptide. GGG is a tripeptide, the most common one. Scientists often use GGG to study amino acids, peptides, and proteins, analyzing the molecular interactions and physicochemical parameters of all three.

“Differences observed between mass spectra of hydrothermally processed and unprocessed triglycine can be regarded as a spectral fingerprint to identify processed GGG in ice grains from icy moons in the solar system,” the authors wrote in their research.

These two panels from the research compare the mass spectra of hydrothermal unprocessed triglycine (left) to hydrothermally processed triglycine (right.) There are some clear differences between the two. Image Credit: Khawaja et al. 2024.

“This delivers very similar mass spectra to the Cassini instrument. We used this to measure an amino acid chain before and after the experiment. In the process, we came across characteristic signals that were caused by the reactions in our simulated hydrothermal field,” Khawaja said.

The researchers intend to repeat this experiment with other organic molecules under extended geophysical conditions in Enceladus’ ocean. “With this new laboratory setup, we will simulate a range of hydrothermal conditions, from the high pressures and temperatures associated with greater depths into the core, to the milder conditions in the ocean water near the water-rock interface,” the authors write in their paper.

The results will allow them to search through Cassini’s data for similar markers. It can also work for future missions to Enceladus and would be further proof of hydrothermal activity on the frozen ocean moon.

If scientists can confirm hydrothermal vents on Enceladus, the excitement that moon generates will only increase.

The post Linking Organic Molecules to Hydrothermal Vents on Enceladus appeared first on Universe Today.

Astronomers were surprised in 1937 when a star in a binary pair suddenly brightened by 1,000 times. The pair is called FU Orionis (FU Ori), and it’s in the constellation Orion. The sudden and extreme variability of one of the stars has resisted a complete explanation, and since then, FU Orionis has become the name for other stars that exhibit similar powerful variability.

The star in question is called Orionis North, and it’s the central star of the pair. Astronomers see its brightening behaviour in old stars but not in young stars like FU Ori. The young star is only about 2 million years old.

Astronomers working with ALMA (Atacama Large Millimetre-submillimetre Array) have discovered the reason behind Fu Ori’s variability. They’ve published their research in the Astrophysical Journal. It’s titled “Discovery of an Accretion Streamer and a Slow Wide-angle Outflow around FU Orionis,” and the lead author is Antonio Hales, deputy manager of the North American ALMA Regional Center and scientist with the NRAO.

Here’s what scientists do know about FU Ori (FUor) stars and their variability. They brighten when they attract gas gravitationally into an accretion disk. Too much mass at once can destabilize the disk, and as material falls into the star, it brightens. But what they didn’t understand was why and how this happened.

“FU Ori has been devouring material for almost 100 years to keep its eruption going. We have finally found an answer to how these young outbursting stars replenish their mass,” explained lead author Hales. “For the first time we have direct observational evidence of the material fueling the eruptions.”

ALMA is the world’s largest radio telescope. It’s an interferometer with 66 separate antennae, which can be moved across the ground to give the observatory a ‘zoom-in’ effect. This powerful observatory has driven a lot of astronomical science.

In this research, ALMA identified a long streamer of carbon monoxide that appears to be falling into FU Ori. The researchers don’t think this streamer has enough material to sustain the star’s current outburst. But it could be the remnant from a past episode. “It is possible that the interaction with a bigger stream of gas in the past caused the system to become unstable and trigger the brightness increase,” explained Hales.

This figure from the research shows 12CO and 13CO emissions as detected by ALMA. The colours denote velocity. The CO streamer of infalling gas is labelled. “The elongated feature has a connection neither to the larger-scale molecular outflow nor to the inner disk rotation and is more similar to accretion streamers recently reported around young stellar objects,” the authors explain. Image Credit: Hales et al. 2024.

The current outburst creates strong stellar winds that interact with a leftover envelope of material from the star’s formation. The wind shocks the envelope, sweeping up carbon monoxide with it. The CO is what ALMA detected.

Artist’s impression of the large-scale view of FU~Ori. The image shows the outflows produced by the interaction between strong stellar winds powered by the outburst and the remnant envelope from which the star formed. The stellar wind drives a strong shock into the envelope, and the CO gas swept up by the shock is what the new ALMA revealed. The inset image is an artist’s impression of the streamer of CO feeding mass into FU Ori. Image Credit: NSF/NRAO/S. Dagnello

ALMA’s ability to operate in different configurations and wavelengths played a role in this work. It allowed the team to detect different types of emissions and to detect the mass flowing into FU Ori. They compared the observations to models of mass flow and accretion streamers. “We compared the shape and speed of the observed structure to that expected from a trail of infalling gas, and the numbers made sense,” said Aashish Gupta, a Ph.D. candidate at European Southern Observatory (ESO). Gupta is a co-author of this work, and he developed the methods used to model the accretion streamer.

This image from the research shows the model results (green line) overlain on ALMA data. The streamer modelling closely matches the data. “The fitting results suggest that the morphology and the velocity profile of the observed streamer emission can be well represented as a trail of infalling gas,” the authors write in their published research. Image Credit: Hales et al. 2024.

The researchers measured the amount of material flowing into FU Ori through the streamer. About 0.07 Jupiter Masses per Myr?1 flow into the young star. Jupiter is about 318 times more massive than Earth. This means that FU Ori’s infall streamer rate is lower than infall around other Class 0 protostars. “This would suggest that the observed streamer will require ?100 Myr to replenish disk masses, which is at least an order of magnitude greater than the typical disk lifetimes,” the authors point out.

The infall streamer and its effect on the star are complex. Not enough material comes in via the streamer to trigger the outbursts. “The streamer needs to be more massive to sustain FU Ori’s outburst accretion rates (by several orders of magnitude). The estimated streamer mass infall rate is not even sufficiently massive to sustain quiescent stellar accretion rates,” the authors explain.

Instead, the infalling material causes disk instability, which in turn delivers enough material to FU Ori to trigger outbursts. “Anisotropic infall, cloudlet capture events, the inhomogeneous delivery of material, and the building up of material around dust traps can all lead to the disk instabilities that could trigger accretion outbursts,” Hales and his co-authors write. They can’t say for sure if this is what’s happening. That would require more modelling, which is outside the scope of this work.

ALMA also spotted another streamer of slow-moving CO. This one is coming from the star rather than falling into it. Hales and his colleagues think this streamer is similar to streamers coming from other young protostellar objects and isn’t related to the brightening. “The ALMA observations reveal the presence of large-scale, wide-angle bipolar outflows for the first time around the class prototype FU Ori,” the researchers write in their paper.

Curiously, astronomers have detected these outflows from other FUor stars but never at FU Ori itself. It’s coming from Fu Ori North, the star that experiences the powerful brightening.

“Prior searches for molecular outflows around FUors, mainly using single-dish telescopes, reported outflowing material from many FUors but failed to detect flows emerging from the FUor class prototype,” the researchers write in their paper. “These nondetections instigated the belief that there were no molecular outflows around the FU Ori system. Our discovery ends the mystery by clearly demonstrating the presence of a molecular outflow from FU Ori itself.”

Understanding young stars is critical because their behaviour governs planet formation. FU Ori’s brightening could have a defining effect on the planets that form around the star.

“By understanding how these peculiar FUor stars are made, we’re confirming what we know about how different stars and planets form,” Hales explained. “We believe that all stars undergo outburst events. These outbursts are important because they affect the chemical composition of the accretion discs around nascent stars and the planets they eventually form.”

For the authors, their research demonstrates how the powerful ALMA observatory makes a unique contribution to astronomical research. “These results demonstrate the value of multiscale interferometric observations to enhance our understanding of the FU Ori outbursting system and provide new insights into the complex interplay of physical mechanisms governing the behaviour of FUor-type and the many other kinds of outbursting stars,” the authors conclude.

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Planetary scientists perk up whenever methane is mentioned. Methane is produced by living things on Earth, so it’s considered to be a potential biosignature elsewhere. In recent years, MSL Curiosity detected methane coming from the surface of Gale Crater on Mars. So far, nobody’s successfully explained where it’s coming from.

NASA scientists have some new ideas.

Ever since Curiosity landed on Mars in 2012, it’s been sensing methane. But the methane displays some odd characteristics. It only comes out at night, it fluctuates with the seasons, and sometimes, the amount of methane jumps to 40 times more than the regular level.

The ESA’s ExoMars Trace Gas Orbiter entered a science orbit around Mars in 2018, and scientists fully expected it to detect methane in the planet’s atmosphere. But it didn’t, and it has never been detected elsewhere on Mars’ surface.

If life was producing the methane, it appears to be restricted to the subsurface under Gale Crater.

There’s no convincing evidence that life exists on Mars. It may have in the past, and it’s possible that some extant life clings to a tenuous existence in subsurface brines or something. But we lack evidence, so life is basically ruled out as the methane source. Especially since the evidence shows life would have to be under Gale Crater and nowhere else.

Scientists have been trying to determine the source of methane, but so far, they haven’t come up with a specific answer. It has something to do with subsurface geological processes involving water, most likely.

This image illustrates possible ways methane might get into Mars’ atmosphere and also be removed from it: microbes (left) under the surface that release the gas into the atmosphere, weathering of rock (right), and stored methane ice called a clathrate. Ultraviolet light can work on surface materials to produce methane as well as break it apart into other molecules (formaldehyde and methanol) to produce carbon dioxide. Credit: NASA/JPL-Caltech/SAM-GSFC/Univ. of Michigan

“It’s a story with a lot of plot twists,” said Ashwin Vasavada, Curiosity’s project scientist at NASA’s Jet Propulsion Laboratory in Southern California, which leads Curiosity’s mission.

Alexander Pavlov is a planetary scientist at NASA’s Goddard Space Flight Center who leads a group of NASA scientists studying the Martian Methane Mystery. In recent research, they suggested that the methane is stored underground. They didn’t explain what produced it, but they showed that methane can be sealed underground by salt solidified in the Martian regolith.

This figure from research published in 2024 illustrates how a salt cap could form and trap methane under the Martian surface. There’s strong evidence of subsurface water on Mars, and it can migrate to the surface and evaporate. Some of the salt in the ground is transported to the surface with the water. Once the water or ice is gone, the salt is left behind in the upper few centimetres of soil. The researchers hypothesized that the salt can become cemented into the same type of duricrust that the InSight lander struggled with. Image Credit: Pavlov et al. 2024.

They suggested that the methane could be released from its subsurface reservoir by the weight of the Curiosity rover itself. The rover’s weight could break the salt seal and release methane in puffs. That’s an interesting proposition, but it doesn’t explain the seasonal and diurnal fluctuations. That makes sense since the Gale Crater is one of only two regions where a rover is working. The other is Jezero Crater, where the Perseverance Rover is working, but it doesn’t have a methane detector. (Neither will the ESA’s Rosalind Franklin rover, which is scheduled to land on Mars in 2029.)

The research group addressed those fluctuations by suggesting that seasonal and daily heating could also break the seal and release methane.

Their potential explanations stem from research Pavlov conducted in 2017. He grew bacteria called halophiles, which grow in salty conditions, in simulated Martian permafrost. The simulated soil was infused with salt, replicating conditions on much of Mars. The microbe growth was inconclusive, but the researchers noticed something else. As the salty ice sublimated, a layer of solidified salt remained, forming a crust.

“We didn’t think much of it at the moment,” Pavlov said.

But he remembered it when MSL Curiosity detected an unexplained burst of methane on Mars in 2019.

“That’s when it clicked in my mind,” Pavlov said. Then, he and a team of researchers began testing conditions that could form the hardened salt seals and then break them open.

Perchlorate is a chemical salt that’s widespread on Mars. Pavlov and his fellow researchers recreated different simulated Martian permafrosts with varying amounts of perchlorate. Inside a Mars simulation chamber, they subjected the samples to different temperatures and atmospheric pressures to see if they would form seals.

In their experiments, they used neon as a methane analog and injected it under the soil. Then, they measured the gas pressure below and above the soil. They found that the pressure was higher under the soil, meaning the gas was being trapped by the salty permafrost. Furthermore, they found that seals formed in samples containing as little as 5% or 10% perchlorate, and they formed within 3 to 13 days. Those are compelling results.

This image shows one of the Mars analog samples with a hardened crust of salt sealing the surface. The lighter colour is where the sample has been scratched. The lighter colour indicates drier soil, and once it was exposed to air outside the Mars Chamber, it quickly absorbed moisture and turned brown. Image Credit: Pavlov et al. 2018.

While 5-10% perchlorate doesn’t sound like much, it’s actually a higher concentration than in Gale Crater, where the methane has been detected. But perchlorate isn’t the only salt in Martian regolith. It also contains sulphates, another type of salt mineral. Pavlov says he and his team will test sulphates next for their ability to form a seal.

The Martian Methane Mystery is commanding a lot of attention. It’s a juicy mystery, and once it’s solved, our understanding of methane as a biosignature or false positive will be much improved. NASA’s 2022 Planetary Mission Senior Review recommended that the issue of methane production and destruction at Mars be investigated further.

The type of work that Pavlov and his colleagues are doing is important, but it’s being held back. Pavlov says that they need more consistent methane measurements. The problem is that Curiosity’s SAM (Sample Analysis at Mars) instrument, which senses the methane, is busy with other tasks. It only checks for methane a few times per year. It’s mostly occupied with drilling samples and testing them, a critical and time-consuming part of the rover’s mission.

The Tunable Laser Spectrometer is one of the tools within the Sample Analysis at Mars (SAM) laboratory on NASA’s Curiosity Mars rover. By measuring the absorption of light at specific wavelengths, it measures concentrations of methane, carbon dioxide and water vapour in Mars’ atmosphere. (Image Credit: NASA/JPL-Caltech)

“Methane experiments are resource intensive, so we have to be very strategic when we decide to do them,” said Goddard’s Charles Malespin, SAM’s principal investigator.

Curiosity’s mission wasn’t designed to measure methane fluctuations. In 2017, NASA said its SAM instrument only sampled the atmosphere 10 times in 20 months. That’s a very inconsistent sample that leaves lots of unanswered questions.

Scientists think another mission is needed to advance their understanding of Martian methane. Rather than one sensor taking irregular methane readings from one location, we need multiple testing stations on the surface that regularly monitor the atmosphere. Nothing like it is in the works.

“Some of the methane work will have to be left to future surface spacecraft that are more focused on answering these specific questions,” Vasavada said.

The post New Answers for Mars’ Methane Mystery appeared first on Universe Today.

Mention the Milky Way and most people will visualise a great big spiral galaxy billions of years old. It’s thought to be a galaxy that took shape billions of years after the Big Bang. Studies by astronomers have revealed that there are the echo’s of an earlier time around us. A team of astronomers from MIT have found three ancient stars orbiting the Milky Way’s halo. The team think these stars formed when the Universe was around a billion years old and that they were once part of a smaller galaxy that was consumed by the Milky Way. 

The Milky Way is our home galaxy within which our entire Solar System and an estimated 400 billion other stars. It measures 100,000 light years from sided to side and is home to almost everything else we can see in the sky with our naked eyes. On a clear dark night we can see the combined light from all the stars in the galaxy forming a wonderful band of hazy light arching across the sky from horizon to horizon. If you could view the Galaxy from the outside its broad shape would resemble two fried eggs stuck back to back.

The story of the discovery takes us back to 2022 during a new Observational Stellar Archaeology course at MIoT when students were learning how they can analyse ancient stars. They then applied them to stars that have not yet been analysed. They worked with data from the 6.5m Magellan-Clay telescope at Las Campanas Observatory and were searching for stars that had formed soon after the Big Bang. At this time in the evolution of the Universe, there was mostly hydrogen and helium with trace amounts of strontium and barium. The team therefore searched for stars with spectra indicating these elements. 

Precision manufacturing is at the heart of the Giant Magellan Telescope. The surface of each mirror must be polished to within a fraction of the wavelength of light. Image: Giant Magellan Telescope Organization

They honed in on just three stars that had been observed in 2013 and 2014 but they had not been previously analysed so were a great study for the students. On completion of their analysis (which took several hundred hours at a computer), the team identified that the stars had very low levels of strontium and barium as predicted if they were ancient stars. The stars they studied were estimated at having formed between 12 and 13 billion years ago. What wasn’t clear was the origin of the stars.  How did they come to be in the Milky Way given that it was relatively new and young. 

The team decided to analyse the orbital characteristics of the stars to see how they moved. The stars were all in different locations through the Milky Way’s halo and all thought to be about 30,000 light years from Earth. Comparing the motion with data from the Gaia astrometric satellite they discovered the stars were going in the opposite direction to the majority of other stars in the Milky Way. We call this retrograde motion and it suggests the stars came from somewhere else, not having formed with the Milky Way. The chemical signatures of the stars coupled with their motion give strong credibility to the liklihood these ancient stars are not native to the Milk Way.

Now they have developed there approach to identify ancient stars, the students are keen to expand their search to see if any others can be located. However with 400 billion stars in the Milky Way, a slightly more efficient method needs to be found. 

Source : MIT researchers discover the universe’s oldest stars in our own galactic backyard

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If you watch astronauts in space then you will know how they seem to float around their spaceship. Spaceships in orbit around the Earth are in free-fall, constantly falling toward surface fo the Earth with the surface constantly falling away from it. Any occupant is also in free-fall but living like this causes muscle tone to degrade slowly. One solution is to generate artificial gravity through acceleration in particular a rotating motion. A new paper makes the case for a rotating space station and goes so far that it is achievable now. 

Acceleration is a change in either direction or speed. In a lift you can feel a deceleration as you feel heavier when the lift slows at the bottom of its descent. It would certainly be possible to generate an artificial force of gravity in a box travelling through space if it constantly accelerates. This would produce a sense of a floor and pin the occupants to the rear wall. This is however, a fairly inefficient way to produce gravity as significant amounts of fuel would be required to continually accelerate the box. 

A recent paper published in Science Direct by lead author Jack J.W.A. van Loon shows how a spaceship that continuously rotates will produce an artificial gravity on the inner skin of the outer shell. The benefits to such an approach are significant; improved crew health and wellbeing, safety improvements, cost reductions and the simplification of numerous flight operations.  

There are many ways that astronauts attempt to limit the impacts on health from micro-gravity. Treadmills with straps to pull the astronauts down onto the running platform are just one of the ways they attempt to keep bones and muscles in tip top condition. If they don’t then bone and muscle density declines. Research has sown that for every month in space, an astronauts’ weight bearing bones become 1% less dense. Muscles wean too and this causes problems on their return to Earth and ‘normal gravity’ so it is a vitally important part of their routine. 

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

The team go on to explore a number of options such as a short arm centrifuge. These would certainly generate artificial gravity but the short arm would mean the gravity gradient from foot to head of occupants would be too great and have a negative health impact. An alternate solution, and more efficient feasible solution is to build a large rotating spacecraft. Such a craft would have benefits for long term missions such as trips to Mars but also benefit those in orbit around Earth for months on end. Savings would be impressive as significant investments are made combatting the effect of microgravity.

The team discuss what would be needed to simulate and Earth-like 1g environment on a spacecraft. A donut shaped spacecraft with a 25 m radius would need to be spun 6 times per minute to generate a 1g environment. Larger spacecraft could be revolved at a slower rate. Doing so not only benefits the astronauts but nearly every aspect of life in space would be enhanced and safer; liquids would behave in a normal way, flames too would behave in a more familiar way, toilets can of a more normal design as can self care systems. The benefits are significant so I don’t think it will be long before we see astronauts walking around in revolving spacecraft enjoying the luxury of normal gravity again. 

Source : Benefits of a rotating – Partial gravity – Spacecraft

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When stars exhaust their hydrogen fuel at the end of their main sequence phase, they undergo core collapse and shed their outer layers in a supernova. Whereas particularly massive stars will collapse and become black holes, stars comparable to our Sun become stellar remnants known as “white dwarfs.” These “dead stars” are extremely compact and dense, having mass comparable to a star but concentrated in a volume about the size of a planet. Despite being prevalent in our galaxy, the chemical makeup of these stellar remnants has puzzled astronomers for years.

For instance, white dwarfs consume nearby objects like comets and planetesimals, causing them to become “polluted” by trace metals and other elements. While this process is not yet well understood, it could be the key to unraveling the metal content and composition (aka. metallicity) of white dwarf stars, potentially leading to discoveries about their dynamics. In a recent paper, a team from the University of Colorado Boulder theorized that the reason white dwarf stars consume neighboring planetesimals could have to do with their formation.

The research team consisted of Tatsuya Akiba, a Ph.D. candidate at UC Boulder with the Joint Institute for Laboratory Astrophysics (JILA) at UC Boulder. He was joined by Selah McIntyre, an undergraduate student in the Department of Chemistry, and Ann-Marie Madigan, a JILA Fellow and a professor in the Department of Astrophysical and Planetary Sciences. Their research was reported in a paper titled “Tidal Disruption of Planetesimals from an Eccentric Debris Disk Following a White Dwarf Natal Kick,” which recently appeared in The Astrophysical Journal.

Planetesimal orbits around a white dwarf. Initially, every planetesimal has a circular, prograde orbit. The kick forms an eccentric debris disk with prograde (blue) and retrograde orbits (orange). Credit: Steven Burrows/Madigan group

Despite their prevalence in our galaxy, the chemical makeup of white dwarfs has puzzled astronomers for years. The presence of heavy metal elements like silicon, magnesium, and calcium on the surfaces of many of these stellar remnants defies what astronomers consider conventional stellar behavior. “We know that if these heavy metals are present on the surface of the white dwarf, the white dwarf is dense enough that these heavy metals should very quickly sink toward the core,” said Akiba in a recent JILA press release. “So, you shouldn’t see any metals on the surface of a white dwarf unless the white dwarf is actively eating something.”

Madigan’s research group at JILA focuses on the gravitational dynamics of white dwarfs and how these affect surrounding material. For their study, the team created computer models that simulated a white dwarf experiencing a rare phenomenon known to occur during its formation. This consisted of an asymmetric mass loss caused by a “natal kick” that altered its motion and the dynamics of the surrounding material. As Professor Madigan explained:

“Simulations help us understand the dynamics of different astrophysical objects. So, in this simulation, we throw a bunch of asteroids and comets around the white dwarf, which is significantly bigger, and see how the simulation evolves and which of these asteroids and comets the white dwarf eats. Other studies have suggested that asteroids and comets, the small bodies, might not be the only source of metal pollution on the white dwarf’s surface. So, the white dwarfs might eat something bigger, like a planet.”

In 80% of their test runs, the team observed that the orbits of comets and planetesimals within 30 to 240 AU (the distance between the Sun and Neptune and well into the Kuiper Belt) of the star became elongated and aligned. They also found that in about 40% of their simulations, the consumed planetesimals came from retrograde orbits. Lastly, they extended their simulations to 100 million years after formation and found that these planetesimals still had elongated orbits and moved as one coherent unit.

Artist’s illustration of crystals forming within a white dwarf. Credit: University of Warwick/Mark Garlick

These new findings also shed light on the origin, chemistry, and future evolution of stars, including our Solar System. In about 5 billion years, our Sun will exit its main sequence phase and grow to become a Red Giant. Roughly 2 billion years later, it will blow off its outer layers in a supernova, leaving behind a white dwarf remnant. Looking ahead, the researchers hope to take their simulations to greater scales to examine how white dwarfs interact with larger planets. These simulations could reveal what will become of the outer planets in our Solar System once our Sun is in its “dead” phase. Said Madigan:

“This is something I think is unique about our theory: we can explain why the accretion events are so long-lasting. While other mechanisms may explain an original accretion event, our simulations with the kick show why it still happens hundreds of millions of years later. The vast majority of planets in the universe will end up orbiting a white dwarf. It could be that 50% of these systems get eaten by their star, including our own solar system. Now, we have a mechanism to explain why this would happen.”

Further Reading: JILA, AJL

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We have discovered over 5,000 planets around other star systems. Amongst the veritable cosmic menagerie of exoplanets, it seems there is a real shortage of Neptune-sized planets close to their star. A new paper just published discusses a Saturn-sized planet close to its host star which should be experiencing mass loss, but isn’t. Studying this world offers a new insight into exoplanet formation across the Universe. 

Exoplanets really are fascinating. Ever-since their discovery the race has been on to discover and catalogue them. It gives us a great opportunity to explore a far more statistically significant set of data to understand planetary system formation rather than just studying are own system.

The absence of Neptune-mass exoplanets closer to the host stars in exoplanetary systems has been a bit of a mystery. Their lack has been attributed to one of two things; photoevaporation – mass is lost through ionisation of gas by radiation which then disperses away form the ionising source or high-eccentricity migration – where the planets move through the planetary system as we have seen with some of the giant planets in our Solar System. 

NASA’s Voyager 2 spacecraft captured these views of Uranus (on the left) and Neptune (on the right) during its flybys of the planets in the 1980s.

To distinguish between these two possibilities a team of astronomers led by Morgan Saidel from the California Institute of Technology investigated the origins of TOI-1259 A b which is a Saturn mass exoplanet. It is in a 3.48 day orbit around a K type star at a distance putting it on the edge of the so called Neptune desert. A region around a star wherein there are no Neptune sized planets. 

In the case of TOI-1259 A b, it is thought that its low density means it is especially vulnerable to photoevaporation. Transit methods were used, observing with the Hale Telescope at Palomar Observatory in the 1083nm helium line to probe the upper levels of the atmosphere. The near-infrared spectrograph on Keck II was also used and showed that there was indeed atmosphere escaping but at a rate lower than expected. The rate of gas loss through photoevaporation (1010.325 g s?1)is too low to significantly have altered the planets mass even if it had formed in its current location.

The hexagonal primary mirror of the Keck II telescope. (Credit: SiOwl. A Wikimedia Commons image under a Creative Commons Attribution 3.0 Unported liscense).

Instead, the team believe that the presence of a white dwarf companion (TOI-1259 B) may have caused the planet to migrate inwards after formation. Analysing the orbital parameters of the planet and the binary star system reveal that high-eccentricity migration is a far more likely explanation. 

Planetary migrations of this sort may leave a trace through accretion of elements in the planetary atmosphere. Quantities of H2O, CO, CO2 , SO2 and CH4 should be at detectable levels in the atmosphere of TOI-1259 A b.  If they are observed through transmission spectroscopic studies, will reveal where in protoplanetary disk the planet formed in. Further studies will be required to finally answer this question. 

Source : Atmospheric Mass Loss from TOI-1259 A b, a Gas Giant Planet With a White Dwarf Companion

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Gravitational wave astronomy has been one of the hottest new types of astronomy ever since the LIGO consortium officially detected the first gravitational wave (GW) back in 2016. Astronomers were excited about the number of new questions that could be answered using this sensing technique that had never been considered before. But a lot of the nuance of the GWs that LIGO and other detectors have found in the 90 gravitational wave candidates they have found since 2016 is lost. 

Researchers have a hard time determining which galaxy a gravitational wave comes from. But now, a new paper from researchers in the Netherlands has a strategy and developed some simulations that could help narrow down the search for the birthplace of GWs. To do so, they use another darling of astronomers everywhere—gravitational lensing.

Importantly, GWs are thought to be caused by merging black holes. These catastrophic events literally distort space-time to the point where their merger causes ripples in gravity itself. However, those signals are extraordinarily faint when they reach us—and they are often coming from billions of light-years away. 

Detectors like LIGO are explicitly designed to search for those signals, but it’s still tough to get a strong signal-to-noise ratio. Therefore, they’re also not particularly good at detailing where a particular GW signal comes from. They can generally say, “It came from that patch of sky over there,” but since “that patch of sky” could contain billions of galaxies, that doesn’t do much to narrow it down.

Fraser discusses the crazy physics that happen when black holes run into each other.

But astronomers lose a lot of context regarding what a GW can tell them about its originating galaxy if they don’t know what galaxy it came from. That’s where gravitational lensing comes in.

Gravitational lenses are a physical phenomenon whereby the signal (in most cases light) coming from a very faraway object is warped by the mass of an object that lies between the further object and us here on Earth. They’re responsible for creating “Einstein Rings,” some of the most spectacular astronomical images.

Light is not the only thing that can be affected by mass, though—gravitational waves can, too. Therefore, it is at least possible that gravitational waves themselves could be warped by the mass of an object between it and Earth. If astronomers are able to detect that warping, they can also tell which specific galaxy in an area of the sky the GW sign is coming from. 

Once astronomers can track down the precise galaxy, creating a gravitational wave, the sky is (not) the limit. They can narrow down all sorts of characteristics not only of the wave-generating galaxy itself but also of the galaxy in front of it, creating the lens. But how exactly should astronomers go about doing this work?

Fraser celebrates the workhorses of the GW detector stable – LIGO and VIRGO – coming back online after upgrades.

That is the focus of the new paper from Ewoud Wempe, a PhD student at the University of Groningen, and their co-authors. The paper details several simulations that attempt to narrow down the origin of a lensed gravitational wave. In particular, they use a technique similar to the triangulation that cell phones use to determine where exactly they are in relation to GPS satellites. 

Using this technique can prove fruitful in the future, as the authors believe there are as many as 215,000 potential GW lensed candidates that would be detectable in data sets from the next generation of GW detectors. While those are still coming online, the theoretical and modeling worlds remain hard at work trying to figure out what kind of data would be expected for different physical realities of this newest type of astronomical observation.

Learn More:
Wempe et al. – On the detection and precise localization of merging black holes events through strong gravitational lensing
UT – After Decades of Observations, Astronomers have Finally Sensed the Pervasive Background Hum of Merging Supermassive Black Holes
UT – A Neutron Star Merged with a Surprisingly Light Black Hole
UT – When Black Holes Merge, They’ll Ring Like a Bell

Lead Image:
Example of a gravitational lens.
Credit – Hubble Telescope / NASA / ESA

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The TRAPPIST-1 solar system generated a swell of interest when it was observed several years ago. In 2016, astronomers using the Transiting Planets and Planetesimals Small Telescope (TRAPPIST) at La Silla Observatory in Chile detected two rocky planets orbiting the red dwarf star, which took the name TRAPPIST-1. Then, in 2017, a deeper analysis found another five rocky planets.

It was a remarkable discovery, especially because up to four of them could be the right distance from the star to have liquid water.

The TRAPPIST-1 system still gets a lot of scientific attention. Potential Earth-like planets in a star’s habitable zone are like magnets for planetary scientists.

Finding seven of them in one system is a unique scientific opportunity to examine all kinds of interlinked questions about exoplanet habitability. TRAPPIST-1 is a red dwarf, and one of the most prominent questions about exoplanet habitability concerns red dwarfs (M dwarfs.) Do these stars and their powerful flares drive the atmospheres away from their planets?

New research in the Planetary Science Journal examines atmospheric escape on the TRAPPIST-1 planets. Its title is “The Implications of Thermal Hydrodynamic Atmospheric Escape on the TRAPPIST-1 Planets.” Megan Gialluca, a graduate student in the Department of Astronomy and Astrobiology Program at the University of Washington, is the lead author.

Most stars in the Milky Way are M dwarfs. As the TRAPPIST-1 makes clear, they can host many terrestrial planets. Large, Jupiter-size planets are comparatively rare around these types of stars.

artist concepts of the seven planets of TRAPPIST-1 with their orbital periods, distances from their star, radii and masses as compared to those of Earth. Credit: NASA/JPL

It’s a distinct possibility that most terrestrial planets are in orbit around M dwarfs.

But M dwarf flaring is a known issue. Though M dwarfs are far less massive than our Sun, their flares are way more energetic than anything that comes from the Sun. Some M dwarf flares can double the star’s brightness in only minutes.

Another problem is tidal locking. Since M dwarfs emit less energy, their habitable zones are much closer than the zones around a main sequence star like our Sun. That means potentially habitable planets are much more likely to be tidally locked to their stars.

That creates a whole host of obstacles to habitability. One side of the planet would bear the brunt of the flaring and be warmed, while the other side would be perpetually dark and cold. If there’s an atmosphere, there could be extremely powerful winds.

“As M dwarfs are the most common stars in our local stellar neighbourhood, whether their planetary systems can harbour life is a key question in astrobiology that may be amenable to observational tests in the near term,” the authors write. “Terrestrial planetary targets of interest for atmospheric characterization with M dwarf hosts may be accessible with the JWST,” they explain. They also point out that future large ground-based telescopes like the European Extremely Large Telescope and the Giant Magellan Telescope could help, too, but they’re years away from being operational.

This is an artist’s impression of the TRAPPIST-1 system, showing all seven planets. Image Credit: NASA

Red dwarfs and their planets are easier to observe than other stars and their planets. Red dwarfs are small and dim, meaning their light doesn’t drown out planets as much as other main-sequence stars do. But despite their lower luminosity and small size, they present challenges to habitability.

M dwarfs have a longer pre-main-sequence phase than other stars and are at their brightest during this time. Once they’re on the main sequence, they have heightened stellar activity compared to stars like our Sun. These factors can both drive atmospheres away from nearby planets. Even without flaring, the closest planet to TRAPPIST-1 (T-1 hereafter) receives four times more radiation than Earth.

“In addition to luminosity evolution, heightened stellar activity also increases the stellar XUV of M dwarf stars, which enhances atmospheric loss,” the authors write. This can also make it difficult to understand the spectra from planetary atmospheres by creating false positives of biosignatures. Exoplanets around M dwarfs are expected to have thick atmospheres dominated by abiotic oxygen.

Despite the challenges, the T-1 system is a great opportunity to study M dwarfs, atmospheric escape, and rocky planet habitability. “TRAPPIST-1 is a high-priority target for JWST General and Guaranteed Time Observations,” the authors write. The JWST has observed parts of the T-1 system, and that data is part of this work.

In this work, the researchers simulated early atmospheres for each of the TRAPPIST-1 (T-1 hereafter) planets, including different initial water amounts expressed in Terrestrial Oceans (TO.) They also modelled different amounts of stellar radiation over time. Their simulations used the most recent data for the T-1 planets and used a variety of different planetary evolution tracks.

In this research, the authors took into account the predicted present-day water content for each of the outer planets and then worked backwards to understand their initial water content. This figure shows “The likelihood of each initial water content (in TO) needed to reproduce the predicted present-day water contents for each of the outer planets,” the authors write. The four outer planets would’ve started out with enormous amounts of water compared to Earth. Image Credit: Gialluca et al. 2024.

The results are not good, especially for the planets closest to the red dwarf.

“We find the interior planets T1-b, c, and d are likely desiccated for all but the largest initial water contents (>60, 50, and 30 TO, respectively) and are at the greatest risk of complete atmospheric loss due to their proximity to the host star,” the researchers explain. However, depending on their initial TO, they could retain significant oxygen. That oxygen could be a false positive for biosignatures.

The outer planets fare a little better. They could retain some of their water unless their initial water was low at about 1 TO. “We find T1-e, f, g, and h lose, at most, approximately 8.0, 4.8, 3.4, and 0.8 TO, respectively,” they write. These outer planets probably have more oxygen than the inner planets, too. Since T1-e, f, and g are in the star’s habitable zone, it’s an intriguing result.

T-1c is of particular interest because, in their simulations, it retains the most atmospheric oxygen regardless of whether the initial TO was high or low.

This artist’s illustration shows what the hot rocky exoplanet TRAPPIST-1 c could look like. Image Credit: By NASA, ESA, CSA, Joseph Olmsted (STScI) – https://webbtelescope.org/contents/media/images/2023/125/01H2TJJF981PWQK9YT0VGH2HPV, Public Domain, https://commons.wikimedia.org/w/index.php?curid=133303919

The potential habitability of T-1 planets is an important question in exoplanet science. The type of star, the number of rocky planets, and the ease of observation all place it at the top of the list of observational targets. We’ll never really understand exoplanet habitability if we can’t understand this system. The only way to understand it better is to observe it more thoroughly.

“These conclusions motivate follow-up observations to search for the presence of water vapour or oxygen on T1-c and future observations of the outer planets in the TRAPPIST-1 system, which may possess substantial water,” the authors write in their conclusion.

The post TRAPPIST-1 Outer Planets Likely Have Water appeared first on Universe Today.

I can remember when Perseverance was launched, travelled out into the Solar System and landed on Mars in February 2021.  In all the time since it arrived, having clocked up 1000 days of exploration, it has collected 23 samples from different geological areas within the Jezero Crater. The area was once home to an ancient lake and if there is anywhere on Mars to find evidence of ancient (fossilised) life, it is here. 

The date was 30 July 2020 when a gigantic Atlas V-541 rocket roared off the launchpad from Cape Canaveral in Florida. On board was the Perseverance rover, on its way to Mars. It arrived around 7 months later, entered the Martian atmosphere and successfully landed using a complex sequence of parachutes, retrorockets and for the first time, a sky crane to lower it from a hovering platform. Its chief purpose on Mars was to explore the geology, climate and atmospheric conditions as a precursor to human exploration. 

A United Launch Alliance Atlas V rocket with NASA’s Mars 2020 Perseverance rover onboard launches from Space Launch Complex 41 at Cape Canaveral Air Force Station, Thursday, July 30, 2020, from NASA’s Kennedy Space Center in Florida. The Perseverance rover is part of NASA’s Mars Exploration Program, a long-term effort of robotic exploration of the Red Planet. Photo Credit: (NASA/Joel Kowsky)

The landing site, the Jezero Crater, was chosen because previous orbital studies revealed clear evidence of an ancient lake that once filled the crater. It is thought that water is a key ingredient to the evolution of life so if there had been a body of water, then there is a greater chance of life evolving. Studying the rocks here is like taking a flick through the history books as it preserves signs of ancient life and also ancient environmental conditions. 

The crater had been formed, like the majority of other craters in the Solar System from some form of impact event. In the case of Jezero it was an asteroid impact around 4 billion years ago. On its arrival at the crater the floor was soon discovered to be made of igneous rock, formed from a huge underground chamber of magma and bought to the surface through volcanic activity. Since then, other types of rock from sand and mud were found providing evidence of the presence of water in Mars’ distant past. 

Jezero Crater on Mars. Credit: NASA/JPL-Caltech/ASU

By the time Perseverance had hit the 1000 day anniversary of its exploration of the red planet it had collected the rock samples, safely packaged them up ready for collection and by and large, completed its exploration of the ancient lake bed. One sample in particular which has been called ‘Lefroy Bay’ has been found to contain fine grained silica. This material is commonly found on Earth and known to preserve fossils. Another of the samples contains phosphate which, on Earth is most definitely associated with biological processes. Both of these contain carbon which can be used to study the environmental conditions from when the rock formed. 

Jezero crater is a big place, 45 kilometres across so deciding on where to collect the samples was challenging. When a target site had been identified, Perseverance would first use its abrasion tool to wear away the surface and then use the onboard instruments such as PIXL, the Planetary Instrument for X-ray Lithochemistry. The instruments on board have the ability to detect both microscopic, fossil-like structures and also to identify chemical changes left behind by ancient microbes. Alas to date, whilst Perseverance has achieved an amazing amount, the detection of signs of life have alluded the rover. 

Source : NASA’s Perseverance Rover Deciphers Ancient History of Martian Lake

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Back in the year 2000, Epsilon Eridani b was discovered. It is a Jupiter-like exoplanet 10.5 light years away but it has taken decades of observations to learn more about the planet. One thing that remains a mystery is it’s orbit which, until recently has been unknown. There has never been a direct image of the planet either, so now, it’s the turn of JWST to see what it can do. 

The concept of exoplanets has been around for a few decades now but the first confirmed discovery occurred in 1992. Astronomers at the Arecibo Observatory discovered a number of Earth-mass planets orbiting around the pulsar PSR B1257+12. Since then, over 5,000 planets have been discovered around other star systems. Astronomers use a number of Studying them once they have been confirmed requires more direct study.

The Arecibo Radio Telescope Credit: UCF

One such exoplanet is known as Epsilon Eridani b which also goes by the name AEgir. Exoplanets are named after their host star (in this case Epsilon Eridani) and the letter ‘b’ designates that it was the first exoplanet discovered around that star. The next to be discovered would be ‘c’ and so on although in the case of Epsilon Eridani it is the only planet. It is thought to orbit around the star at a distance of 3.5 astronomical units (where 1 AU is the average distance between the Sun and Earth) and takes about 7.6 years to complete one orbit.  

One area of exoplanet study that has been lacking over recent years is the study of the surface and atmospheric conditions, in particular a study into their potential habitability. Cold exoplanets seem to have received the least study due to their faint appearance in the mid-infrared wavelength. Due to the properties of these cold planets, direct imaging techniques are required and must employ high contrast processes.  To date, no instrument has been capable of delivering. 

The crux of the challenge is that the cold exoplanets have no intrinsic energy source and only re-use the radiation from the host star. Their luminosity is based upon their size and distance from host star but usually the radiation is at the same wavelength as the emission from the star. To address this challenge, a paper has been published in ‘Astronomy & Astrophysics’ journal by a team led by C. Tschudi from the Institute for Particle Physics and Astrophysics in Switzerland.

The paper provides an insight into high contrast observations of Epsilon Eridani taken in 20198 and 2020 using the VLT (Very Large Telescope). Using the SPHERE instrument (Spectro-Polarimetric High-contrast Exoplanet Research) as part of the ongoing RefPlanets programme, the team were able to use polarising technology to search for signals from the planet. 

In mid-August 2010 ESO Photo Ambassador Yuri Beletsky snapped this amazing photo at ESO’s Paranal Observatory. A group of astronomers were observing the centre of the Milky Way using the laser guide star facility at Yepun, one of the four Unit Telescopes of the Very Large Telescope (VLT). Yepun’s laser beam crosses the majestic southern sky and creates an artificial star at an altitude of 90 km high in the Earth’s mesosphere. The Laser Guide Star (LGS) is part of the VLT’s adaptive optics system and is used as a reference to correct the blurring effect of the atmosphere on images. The colour of the laser is precisely tuned to energise a layer of sodium atoms found in one of the upper layers of the atmosphere — one can recognise the familiar colour of sodium street lamps in the colour of the laser. This layer of sodium atoms is thought to be a leftover from meteorites entering the Earth’s atmosphere. When excited by the light from the laser, the atoms start glowing, forming a small bright spot that can be used as an artificial reference star for the adaptive optics. Using this technique, astronomers can obtain sharper observations. For example, when looking towards the centre of our Milky Way, researchers can better monitor the galactic core, where a central supermassive black hole, surrounded by closely orbiting stars, is swallowing gas and dust. The photo, which was chosen as Astronomy Picture of the Day for 6 September 2010 and Wikimedia Picture of the Year 2010, was taken with a wide-angle lens and covers about 180 degrees of the sky.   This image is available as a mounted image in the ESOshop.   #L

Unfortunately the team were unable to successfully detect Epsilon Eridani b despite a total exposure time of 38.5 hours spread over 12 nights. This was however, useful at understanding the limitations of the instrumentation. What next then? Well it looks like we have to wait for a next generation of infrared sensitive instruments to peer deeper into the system. The James Webb telescope is a fine example of such a device and, once it turns its sights onto Epsilon Eridani maybe the mysteries will finally be resolved.

Source : SPHERE RefPlanets: Search for ? Eridani b and warm dust

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Primordial Black Holes (PBHs) have recently received much attention in the physics community. One of the primary reasons is the potential link to dark matter. In effect, if PBHs can be proven to exist, there’s a very good chance that they are what dark matter, the invisible thing that makes up 85% of the universe’s mass, is made of. If proven, that would surely be a Nobel-level discovery in astrophysics. 

But to prove it, someone has to find them first. So far, PBHs exist only in theory. But we’re getting closer to proving they do exist, and a new paper from Marcos Flores of the Sorbonne and Alexander Kusenko of UCLA traces some ideas on how we might be able to finally find PBHs and thereby prove or disprove their connection to dark matter.

Drs. Flores and Kusenko focus on understanding PBH formation theories and then extrapolate how those formations might be detectable, even with modern equipment. A typical black hole, which we know exists, forms when supermassive stars collapse under their own weight.

Fraser discusses PBHs.

PBHs were formed before any stars of such size were available to collapse, so they must be formed using a different mechanism. The paper details a theorized PBH formation process that involves a detailed mathematical look at particle asymmetry and how that fits in with other models of particle physics. But how can astronomers see those formations?

One way is by watching a loss of angular momentum. Astronomers can observe “halos” of particles early on in the universe. In many cases, they are spinning rapidly. However, if their spin slows dramatically, it may indicate that a PBH was forming in the vicinity, sapping some of the energy from that angular momentum by pulling the particles towards themselves.

Another way is by watching a new favorite mechanism of astronomers everywhere – gravitational waves. It’s not completely clear whether the formation of PBHs can cause gravitational waves. Still, the paper discusses some frameworks that can potentially lead to a theory of whether they do. 

Fraser discusses how hard it is to find PBHs with Dr. Celeste Keith.

Supersymmetry provides one of those frameworks. In some cases, the early universe operating under the principles of supersymmetry could form a PBH that would form a gravitational wave that the next generation of gravitational wave detectors could potentially detect. In particular, it would involve what the paper calls a “poltergeist mechanism” resulting from space-time perturbations in certain theories. 

A final way to detect these PBHs is to watch for gravitational lenses. Some experiments like the Optical Gravitational Lensing Experiment (OGLE) and the Hyper Suprime-Cam (HSC) of the Subaru telescope have noticed gravitational microlensing where there is no known massive object to cause such lensing. PBHs, which would be effectively invisible to those telescopes, could offer one explanation, though other explanations must be ruled out first.

Other theories offer other opportunities for PBH detection, including watching the interaction of “Q-balls” or theoretical large “blobs” of matter. If enough of these are collected together, they could potentially form a PBH. 

Ultimately, there are more questions than answers surrounding these mysterious objects. If they do exist, they could answer plenty of them. However, more data is needed to prove that beyond any reasonable doubt. Experimentalists are already pushing forward as quickly as they can to develop new and better detectors that can help in the hunt for PBHs. If they do exist, it’s only a matter of time before we find them.

Learn More:
Flores & Kusenko – New ideas on the formation and astrophysical detection of primordial black holes
UT – The Universe Could Be Filled With Ultralight Black Holes That Can’t Die
UT – If We Could Find Them, Primordial Black Holes Would Explain a Lot About the Universe
UT – Neutron Stars Could be Capturing Primordial Black Holes

Lead Image:
Illustration of colliding black holes.
Credit – Caltech / R. Hurt (IPAC)

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We already know that water has existed on the surface of Mars but for how long? Curiosity has been searching for evidence for the long term presence of water on Mars and now, a team of researchers think they have found it. The rover has been exploring the Gale Crater and found it contains high concentrations of Manganese. The mineral doesn’t form easily on Mars so the team think it may have formed as deposits in an ancient lake. It is interesting too that life on Earth helps the formation of Manganese so its presence on Mars is a mystery.

The Mars Curiosity Rover was launched in November 2011. It arrived on 6 August 2012 in the Gale Crater region of Mars. It’s purpose was to explore the geology of the area, climatic conditions and the potential for habitability for future explorers.  We have seen stunning images from the surface of Mars thanks to Curiosity and our understanding of Mars both past and present has been improved as a result of its work. 

New simulations are helping inform the Curiosity rover’s ongoing sampling campaign. Credit:NASA/JPL-Caltech/MSSS

A paper published in the Journal of Geophysical Research : Planets has reported on findings using the ChemCam instrument on board Curiosity. The paper’s lead author Patrick Gasda from the Los Alamos National Laboratory’s Space Science and Application group announced the findings of high levels of manganese in rocks from the base of the crater. It is thought that the Gale Crater is an ancient lake so this poses interesting questions as to its origin. 

On Earth, biological processes are fundamental to the formation of materials like manganese oxide with photosynthesis producing atmospheric oxygen. There are also microbes that act as a catalyst to the oxidisation of manganese. The problem is that there is no such sign other life on Mars so the process that led to the formation of oxygen in the ancient Martian atmosphere is unclear. If we cannot understand the formation of oxygen, then we struggle to understand how manganese oxide might form. Perhaps something relating to large bodies of surface water could be responsible. 

The ChemCam instrument on Curiosity uses a laser to generate small amounts of plasma on the surface of Martian rocks. Light is then collected to enable the composition of the rock to be identified. The team studied sand, silts and muds, the former being more porous than the latter. The majority of the manganese found in the sands is thought to have been the result of ground water percolation. On Earth the manganese is oxidised by atmospheric oxygen in a process that is accelerated by microbes. 

We still don’t have all the answers but but the study has revealed yet again, to an environment that was once suitable for life. That environment seems similar to many places on Earth that also display rich manganese deposits. 

Source : New findings point to an Earth-like environment on ancient Marsh

The post These Rocks Formed in an Ancient Lake on Mars appeared first on Universe Today.

“A dream come true.”
“I never expected this!”
“The most amazing light show I’ve ever seen in my life!”
“Once in a lifetime!”
“No doubt, this weekend will be remembered as ‘that weekend.’”

That’s how people described their views of the Aurora borealis this weekend, which put on a breathtaking celestial show around the world, and at lower latitudes than usual. This allowed hundreds of millions of people to see the northern lights for the first time in their lives. People as far south as Arizona and Florida in the US and France, Germany and Poland in Europe got the views of their life as a series of intense solar storms – the most powerful in more than 20 years – impacted Earth’s atmosphere starting Friday and through the weekend.

As we reported on Friday, a giant Earth-facing sunspot group named AR3664 hurled at least six coronal mass ejections our way, triggering a dazzling display of breathtaking celestial shows over several nights. NOAA’s Space Weather Prediction Center issued a geomagnetic storm watch in anticipation of G4 or G5 events; G5 is the highest rating on NOAA’s space weather scale. This means not only was there a spectacular sky show, but some electrical grid systems could have experienced blackouts; however, there was no widespread reports of any problems or damage to electrical grids.

“Watches at this level are very rare,” the SWPC said in an advisory on Saturday.

Let’s take a look at the incredible views of our readers and friends, many shared on Universe Today’s Flickr page. Our lead image comes from Julien Looten, who took this photo at the cliffs of Étretat in northern France. Looten said, “These auroras began to be visible around 10:30 PM, even before nightfall… From then on, they were visible to the naked eye until dawn… Without interruption…”

A spectacular light show over North Cascades National Park, Washington state, USA. Credit: Patrick Vallely. Used by permission. A 360° panorama of the May 10/11, 2024 great aurora display, as seen in southern Alberta, Canada. This is a stitch of 20 segments, each 13-second exposures, with “very odd vertical blue and magenta rays.” Credit: Alan Dyer/AmazingSky.com A unique orange and red aurora seen over Vancouver Island, British Columbia, Canada. Credit: Karla Thompson.

No doubt this weekend will be remembered as 'that weekend'. Here's my rushed, ordinary photos of an extraordinary event.
Taken locally in Cheshire during the 'spike' at 03:00 Saturday. Zero colour enhancement in post processing. The greens were JUST visible with the naked eye: pic.twitter.com/Z9uQA4fFaW

— Andy Saunders – Apollo Remastered (@AndySaunders_1) May 12, 2024 Ohio’s Aurora 05-10-2024, captured in front of John Chumack’s observatory domes at JBSPO in Yellow Springs, Ohio. Canon 6DDSLR 16mm F2.8 lens, ISO 1250, 10 second exposure. Credit: John Chumack, galacticimages.com. Used by permission.

"Once in a Lifetime" – The Needles, Isle of Wight, UK
Credit @chadpowellphoto pic.twitter.com/NAoi6k9h9E

— Chad Powell (@chadpowellphoto) May 12, 2024 “Bonkers” aurora display in Tucson, Arizona, USA. Credit: Robert Sparks. Used by permission.

8 hrs, 2 camera batteries, 500 photos & a full memory card later, we're home after our epic aurora hunt. Just a magical, magnificent night. Aurora filling the sky at one point, green curtains/ red/pink rays & beams, reflected in the reservoir we were parked next to up nr Shap… pic.twitter.com/0iApnjZ05H

— Stuart Atkinson (@mars_stu) May 11, 2024 Aurora over Raisting Earth Station near near Raisting, Bavaria, Germany. “We experienced three waves of incredibly strong Aurora, especially for our rather Southern latitude. During the second wave we saw individual pulsating filaments dancing over our heads. What a breathtaking experience!” Credit: Simeon Schmauß, used by permission. The aurora as seen in the Rocky Mountains west of Denver on May10-11, 2024, taken with an iPhone. Credit: Carolyn Collins Petersen. This timelapse from May 10-11 shows a fish-eye view of the sky in the Rocky Mountains of Colorado. Credit: Mark C. Petersen/Loch Ness Productions

I asked a complete stranger to take my photo during the stunning aurora show. I did the same for her.
Seeing the aurora from our location was incredible. We will treasure the memory of our shared experience.
10.05.24 Bedfordshire UK #aurora #auroraUK #StormHour #ThePhotoHour pic.twitter.com/vWwAjSQK2I

— Dawn (@DawnSunrise1) May 12, 2024 This colorful auroral display was visible from Bishopmill, Scotland, UK on May 10, 2024. “It was capped by several beautiful coronae, the holy grail for many aurora photographers. At times, the colours were clearly visible to the unaided eye.” Credit: Alan Tough. Used by permission. A beautiful aurora, with the International Space Station passing by, right at the zenith. Seen south of Peterborough (Keene), Ontario, with tripod mounted Canon EOS 60D and Bower 8mm prime lens with ISO 800 and 10 seconds. “It doesn’t get much better than this, the best display here in 15 years at least!” Credit: Rick Stankiewicz, Peterborough Astronomical Association (PAA).

The sky opened over Bear Lake, Utah pic.twitter.com/zW3nSRafZa

— Riding with Robots (@ridingrobots) May 11, 2024 Aurora on May 10/11 2024, taken from Ottawa, Canada with an iPhone 14 Pro Max. Credit: Andrew Symes. Used by permission. Aurora Borealis on May 10, 2024 From British Columbia, Canada. Credit: Debra Ceravolo. Used by permission. “The moment when the Great Aurora of 2024 went from looking average to exploding and filling the entire sky. Until that moment, it looked cool, but nothing I hadn’t seen from this location before. The curious part was it was in the western sky instead of the north when I normally see it. But in this moment, the entirity of the visible sky lit up in the most amazing light show I’ve ever seen in my life. Credit: Dark Arts Astrophotography. Used by permission. Unique view of the KP9 aurora on May 11, 2024 at Owen Sound, Ontario, Canada. Credit: Northern Lights Graffiti. Used by permission

The amount of insane beauty that’s on my memory cards right now is almost overwhelming. Aurora chasing may be my new addiction.

I also will likely release a shot or two in print, so if you want a memento from this event make sure you’re on my email list! pic.twitter.com/OjrthGlqJB

— Andrew McCarthy (@AJamesMcCarthy) May 12, 2024 Aurora and the Moon seen over central Minnesota, USA. Credit: Nancy Atkinson

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