SwRI investigations reveal more evidence that Mimas is a stealth ocean world

Resized Image using AI by SFLORG
Image Credit: Courtesy of NASA/JPL/SSI/SwRI

When a Southwest Research Institute scientist discovered surprising evidence that Saturn’s smallest, innermost moon could generate the right amount of heat to support a liquid internal ocean, colleagues began studying Mimas’ surface to understand how its interior may have evolved. Numerical simulations of the moon’s Herschel impact basin, the most striking feature on its heavily cratered surface, determined that the basin’s structure and the lack of tectonics on Mimas are compatible with a thinning ice shell and geologically young ocean.

“In the waning days of NASA’s Cassini mission to Saturn, the spacecraft identified a curious libration, or oscillation, in Mimas’ rotation, which often points to a geologically active body able to support an internal ocean,” said SwRI’s Dr. Alyssa Rhoden, a specialist in the geophysics of icy satellites, particularly those containing oceans, and the evolution of giant planet satellite systems. She is the second author of a new Geophysical Research Letters paper on the subject. “Mimas seemed like an unlikely candidate, with its icy, heavily cratered surface marked by one giant impact crater that makes the small moon look much like the Death Star from Star Wars. If Mimas has an ocean, it represents a new class of small, ‘stealth’ ocean worlds with surfaces that do not betray the ocean’s existence.”

Volcano-like rupture could have caused magnetar slowdown

An artist's impression of a magnetar eruption. 
Illustration Credit: NASA's Goddard Space Flight Center

On Oct. 5, 2020, the rapidly rotating corpse of a long-dead star about 30,000 light years from Earth changed speeds. In a cosmic instant, its spinning slowed. And a few days later, it abruptly started emitting radio waves.

Thanks to timely measurements from specialized orbiting telescopes, Rice University astrophysicist Matthew Baring and colleagues were able to test a new theory about a possible cause for the rare slowdown, or “anti-glitch,” of SGR 1935+2154, a highly magnetic type of neutron star known as a magnetar.

In a study published this month in Nature Astronomy, Baring and co-authors used X-ray data from the European Space Agency’s X-ray Multi-Mirror Mission ( XMM-Newton) and NASA’s Neutron Star Interior Composition Explorer ( NICER) to analyze the magnetar’s rotation. They showed the sudden slowdown could have been caused by a volcano-like rupture on the surface of the star that spewed a “wind” of massive particles into space. The research identified how such a wind could alter the star’s magnetic fields, seeding conditions that would be likely to switch on the radio emissions that were subsequently measured by China’s Five-hundred-meter Aperture Spherical Telescope ( FAST).

Astronomers use novel technique to find starspots

Sunspots
Image Credit: HMI / SFLORG/ Via ESO Helioviewer

Astronomers have developed a powerful technique for identifying starspots, according to research presented this month at the 241st meeting of the American Astronomical Society, and published in the journal Monthly Notices of the Royal Astronomical Society

Our sun is at times dotted with sunspots, cool dark regions on the stellar surface generated by strong magnetic fields, which suppress churning motions and impede the free escape of light. "On other stars, these phenomena are called starspots," said Lyra Cao, lead author of the study and a graduate student in astronomy at The Ohio State University. 

“Our study is the first to precisely characterize the spottiness of stars and use it to directly test theories of stellar magnetism,” said Cao. “This technique is so precise and broadly applicable that it can become a powerful new tool in the study of stellar physics.”

Use of the technique will soon allow Cao and her colleagues to release a catalog of starspot and magnetic field measurements for more than 700,000 stars – increasing the number of these measurements available to scientists by three orders of magnitude.

Asteroid findings from specks of space dust could save the planet

Itokawa seen in close-up
Image Credit: JAXA

Curtin University-led research into the durability and age of an ancient asteroid made of rocky rubble and dust, revealed significant findings that could contribute to potentially saving the planet if one ever hurtled toward Earth.

The international team studied three tiny dust particles collected from the surface of ancient 500-metre-long rubble pile asteroid, Itokawa, returned to Earth by the Japanese Space Agency’s Hayabusa 1 probe.

The study’s results showed asteroid Itokawa, which is 2 million kilometers from Earth and around the size of Sydney Harbour Bridge, was hard to destroy and resistant to collision.

Lead author Professor Fred Jourdan, Director of the Western Australian Argon Isotope Facility, part of the John de Laeter Centre and the School of Earth and Planetary Sciences at Curtin, said the team also found Itokawa is almost as old as the solar system itself.

“Unlike monolithic asteroids, Itokawa is not a single lump of rock, but belongs to the rubble pile family which means it’s entirely made of loose boulders and rocks, with almost half of it being empty space,” Professor Jourdan said.

A new model for dark matter

This NASA Hubble Space Telescope image shows the distribution of dark matter in the center of the giant galaxy cluster Abell 1689, containing about 1,000 galaxies and trillions of stars. Dark matter is an invisible form of matter that accounts for most of the universe’s mass. Hubble cannot see the dark matter directly. Astronomers inferred its location by analyzing the effect of gravitational lensing, where light from galaxies behind Abell 1689 is distorted by intervening matter within the cluster. Researchers used the observed positions of 135 lensed images of 42 background galaxies to calculate the location and amount of dark matter in the cluster. They superimposed a map of these inferred dark matter concentrations, tinted blue, on an image of the cluster taken by Hubble’s Advanced Camera for Surveys. If the cluster’s gravity came only from the visible galaxies, the lensing distortions would be much weaker. The map reveals that the densest concentration of dark matter is in the cluster’s core. Abell 1689 resides 2.2 billion light-years from Earth. The image was taken in June 2002.
Image credit: NASA, ESA, D. Coe (NASA Jet Propulsion Laboratory/California Institute of Technology, and Space Telescope Science Institute), N. Benitez (Institute of Astrophysics of Andalusia, Spain), T. Broadhurst (University of the Basque Country, Spain), and H. Ford (Johns Hopkins University)

Dark matter remains one of the greatest mysteries of modern physics. It is clear that it must exist, because without dark matter, for example, the motion of galaxies cannot be explained. But it has never been possible to detect dark matter in an experiment.

Currently, there are many proposals for new experiments: They aim to detect dark matter directly via its scattering from the constituents of the atomic nuclei of a detection medium, i.e., protons and neutrons.

A team of researchers—Robert McGehee and Aaron Pierce of the University of Michigan and Gilly Elor of Johannes Gutenberg University of Mainz in Germany—has now proposed a new candidate for dark matter: HYPER, or “HighlY Interactive ParticlE Relics.”

Tumultuous migration on the edge of the Hot Neptune Desert

Did hot Neptunes ever exist? While astronomers observe gas giants and small rocky planets close to their stars, the SPICE DUNE project is investigating the ‘‘desert’’ of Neptune-sized planets.
Illustration Credit: © Elsa Bersier - CFPArts / ESBDi Genève

A UNIGE team reveals the eventful migration history of planets bordering the Hot Neptune Desert, these extrasolar planets that orbit very close to their star.

 All kinds of exoplanets orbit very close to their star. Some look like the Earth, others like Jupiter. Very few, however, are similar to Neptune. Why this anomaly in the distribution of exoplanets? Researchers from the University of Geneva (UNIGE) and the National Centre of Competence in Research (NCCR) PlanetS have observed a sample of planets located at the edge of this Hot Neptune Desert to understand its creation. Using a technique combining the two main methods of studying exoplanets (radial velocities and transits), they were able to establish that a part of these exoplanets has migrated in a turbulent way near their star, which pushed them out of the orbital plane where they were formed. These results are published in the specialized journal Astronomy & Astrophysics.

Astronomers use ‘little hurricanes’ to weigh and date planets around young stars

The protoplanetary disc surrounding the young star HL Tauri. These new ALMA observations reveal substructures within the disc that have never been seen before and even show the possible positions of planets forming in the dark patches within the system. 
Image Credit: ALMA (ESO/NAOJ/NRAO)

Researchers from the University of Cambridge and the Institute for Advanced Study have developed a technique, which uses observations of these ‘hurricanes’ by the Atacama Large Millimeter/submillimeter Array (ALMA) to place some limits on the mass and age of planets in a young star system.

Pancake-like clouds of gases, dust and ice surrounding young stars – known as protoplanetary discs - are where the process of planet formation begins. Through a process known as core accretion, gravity causes particles in the disc to stick to each other, eventually forming larger solid bodies such as asteroids or planets. As young planets form, they start to carve gaps in the protoplanetary disc, like grooves on a vinyl record.

Even a relatively small planet – as small as one-tenth the mass of Jupiter according to some recent calculations – may be capable of creating such gaps. As these ‘super-Neptune’ planets can orbit their star at a distance greater than Pluto orbits the Sun, traditional methods of exoplanet detection cannot be used.

In addition to the grooves, observations from ALMA have shown other distinct structures in protoplanetary discs, such as banana- or peanut-shaped arcs and clumps. It had been thought that at least some of these structures were also driven by planets.

James Webb Telescope Reveals Milky Way-like Galaxies in Young Universe

The power of JWST to map galaxies at high resolution and at longer infrared wavelengths than Hubble allows it look through dust and unveil the underlying structure and mass of distant galaxies. This can be seen in these two images of the galaxy EGS23205, seen as it was about 11 billion years ago. In the HST image (left, taken in the near-infrared filter), the galaxy is little more than a disk-shaped smudge obscured by dust and impacted by the glare of young stars, but in the corresponding JWST mid-infrared image (taken this past summer), it’s a beautiful spiral galaxy with a clear stellar bar.
Image Credit: NASA/CEERS/University of Texas at Austin

New images from NASA’s James Webb Space Telescope (JWST) reveal for the first-time galaxies with stellar bars — elongated features of stars stretching from the centers of galaxies into their outer disks — at a time when the universe was a mere 25% of its present age. The finding of so-called barred galaxies, similar to our Milky Way, this early in the universe will require astrophysicists to refine their theories of galaxy evolution.

Prior to JWST, images from the Hubble Space Telescope had never detected bars at such young epochs. In a Hubble image, one galaxy, EGS-23205, is little more than a disk-shaped smudge, but in the corresponding JWST image taken this past summer, it’s a beautiful spiral galaxy with a clear stellar bar.

“I took one look at these data, and I said, ‘We are dropping everything else!’” said Shardha Jogee, professor of astronomy at The University of Texas at Austin. “The bars hardly visible in Hubble data just popped out in the JWST image, showing the tremendous power of JWST to see the underlying structure in galaxies,” she said, describing data from the Cosmic Evolution Early Release Science Survey (CEERS), led by UT Austin professor, Steven Finkelstein.

Russian Scientists Learned to Create Analogues of Space Ice

Astronomers from Ural Federal University have grown ice in a vacuum installation.
Photo Credit: Aldebaran S

Employees of the Ural Federal University's Youth Research Laboratory of Astrochemical Research grew the first samples of interstellar ice analogs and for the first time obtained test infrared spectra of these ices (the quality of the spectra is not inferior to those obtained in foreign laboratories). Obtaining analogues of interstellar ice in the laboratories is important because it will help to analyze data from telescopes, in particular James Webb (JWST), and to determine the chemical composition of interstellar ice and its structure in space.

"Until a year ago, experiments to obtain spectra of interstellar ice analogs were conducted only abroad. Now we can conduct them in Russia as well. The quality of the obtained spectra is not inferior to those obtained in foreign laboratories. It is also important to note that one of the key elements of our experimental setup, the turbomolecular pump, is made in Russia," Anton Vasyunin, Head of the Scientific Laboratory for Astrochemical Research at UrFU, commented on the results.

Interstellar ice forms in the cold formation regions of stars and planets from atoms and molecules that freeze at low temperatures from gas on the surface of microscopic cosmic dust particles. Studies of interstellar ice are necessary to understand the chemical evolution of the galaxy and to find answers to fundamental questions, in particular about the origin of life in the universe.

Alien Planet Found Spiraling to its Doom around an Aging Star

An artist's concept of the Kepler-1658 system. Kepler-1658b, orbiting with a period of just 3.8 days, was the first exoplanet candidate discovered by Kepler. 
Illustration Credit: Gabriel Perez Diaz/Instituto de Astrofísica de Canarias

For the first time, astronomers have spotted an exoplanet whose orbit is decaying around an evolved, or older, host star. The stricken world appears destined to spiral closer and closer to its maturing star until collision and ultimate obliteration.

The discovery offers new insights into the long-winded process of planetary orbital decay by providing the first look at a system at this late stage of evolution. Death-by-star is a fate thought to await many worlds and could be the Earth's ultimate adios billions of years from now as our Sun grows older.

"We've previously detected evidence for exoplanets inspiraling toward their stars, but we have never before seen such a planet around an evolved star," says Shreyas Vissapragada, a 51 Pegasi b Fellow at the Center for Astrophysics | Harvard & Smithsonian and lead author of a new study describing the results. "Theory predicts that evolved stars are very effective at sapping energy from their planets' orbits, and now we can test those theories with observations."

Samples From Asteroid Ryugu Help Us Learn About Earth's Origins

The elemental composition of the Earth comes from its fiery past, through accretion of various solar system objects. New samples collected by the Hayabusa2 space mission provide insight into the origins of moderately volatile elements such as zinc and copper. Tokyo Tech researchers have linked the material from the Cb-type asteroid, Ryugu, to the elemental composition of the Earth. Their results suggest that Ryugu-type material played a significant role in the genetic heritage of the Earth's elemental composition.

Understanding the origins of Earth's elemental composition offers a glimpse into the history of our planet. One way to learn about this is to investigate the meteorites that would have similar composition with materials that contributed to the accretion of planet Earth in its early development. Meteorites are divided into multiple classes based on their composition. The most primitive and common of these classes includes chondrites, which further includes carbonaceous chondrites (CCs). Of these, Ivuna-type (CI) CCs have an elemental composition that is nearly identical with that of the solar photosphere, which therefore can be used as a key reference for understanding how early solar system processes shaped planets and their building blocks. The Hayabusa2 spacecraft's mission was to collect samples from the Cb-type asteroid (162173), Ryugu. As the elemental composition of returned Ryugu samples is unaffected by further terrestrial processes, the two successful sampling events on Ryugu offer a plethora of unprecedented information.

Astronomers discover clues about stellar ‘glitching’

Stars that experience structural "glitches" during their lifetimes may be more common than first thought.

Astronomers have found a way to peer into the physics of some of the brightest stars in the sky.

Using data from NASA’s Kepler space telescope, an international team of researchers has found new evidence that red giants, dying stars that have exhausted their supply of hydrogen and are in the final stages of stellar evolution, often experience large-scale structural variations, or what are known as “glitches” deep inside their inner core.

The stellar glitches popularized in the media have to do with a star’s rotation, but lead author Mathieu Vrard studies a different kind of defect. The glitches in this study can affect a star’s oscillations, or the frequencies and paths that sound waves travel when passing through a star.

Red clump stars, helium-core burning objects, are often used in astrophysical studies as probes of distance to measure aspects like galaxy density, and to learn more about the physical processes behind stellar chemical evolution. So, it’s vital that scientists understand why these discontinuities happen, said Vrard, a postdoctoral research associate in astronomy at the Ohio State University.

“By analyzing these variations, we can use them to obtain not only the global parameters of the star, but also information on the precise structure of those objects,” he said.

Comet Impacts Could Bring Ingredients for Life to Europa’s Ocean

An artist's concept of a comet or asteroid impact on Jupiter's moon Europa.
Illustration Credit: NASA/JPL-Caltech

Comet strikes on Jupiter’s moon Europa could help transport critical ingredients for life found on the moon’s surface to its hidden ocean of liquid water — even if the impacts don’t punch completely through the moon’s icy shell.

The discovery comes from a study led by researchers at The University of Texas at Austin, where researchers developed a computer model to observe what happens after a comet or asteroid strikes the ice shell, which is estimated to be tens of kilometers thick.

The model shows that if an impact can make it at least halfway through the moon’s ice shell, the heated meltwater it generates will sink through the rest of the ice, bringing oxidants — a class of chemicals required for life — from the surface to the ocean, where they could help sustain any potential life in the sheltered waters.

The researchers compared the steady sinking of the massive melt chamber to a foundering ship.

Scientists get first-ever sound recording of dust devils on Mars

Roger Wiens, a planetary scientist and Mars rover expert at Purdue University, with a topographical model of Mars and a photo of Curiosity.
Photo Credit: John Underwood / Purdue University

When the rover Perseverance landed on Mars, it was equipped with the first working microphone on the planet’s surface. Scientists have used it to make the first-ever audio recording of an extraterrestrial whirlwind.

The study was published in Nature Communications by planetary scientist Naomi Murdoch and a team of researchers at the National Higher French Institute of Aeronautics and Space and NASA. Roger Wiens, professor of earth, atmospheric and planetary sciences in Purdue University’s College of Science, leads the instrument team that made the discovery. He is the principal investigator of Perseverance’s SuperCam, a suite of tools that comprise the rover’s “head” that includes advanced remote-sensing instruments with a wide range of spectrometers, cameras and the microphone.

“We can learn a lot more using sound than we can with some of the other tools,” Wiens said. “They take readings at regular intervals. The microphone lets us sample, not quite at the speed of sound, but nearly 100,000 times a second. It helps us get a stronger sense of what Mars is like.”

UH lab produces building blocks to DNA and RNA in deep space

Conceptualization of the role of methanediamine in the galactic cosmic ray mediated synthesis of DNA and RNA bases in deep space.
Illustration Credit: University of Hawaiʻi

The synthetic production of a critical building block called methanediamine for the first time by researchers in University of Hawaiʻi at Mānoa’s Department of Chemistry could lead to key insights into the origins of life. The researchers have discovered a method to produce it in a lab under conditions that mimic icy interstellar nanoparticles in cold molecular clouds in space.

Nitrogen is the most abundant element in Earth’s atmosphere. It is also incorporated into nearly one-third of some 300 molecules identified in the interstellar medium, which is the material that exists in the space between the stars in a galaxy.

Most nitrogen-containing molecules in deep space carry exclusively the nitrile moiety (organic compound that has a carbon, nitrogen functional group), while amines (a member of a family of nitrogen-containing organic compounds that is derived from ammonia) and imines (compounds containing a carbon-nitrogen double bond) are relatively rare. According to experts, an understanding of the origin of these less common molecule parts in deep space is central to the hypothesis for the origin of life because all nucleobases (nitrogen-containing compounds) found in contemporary RNA and DNA contain amines and imines.

SwRI Study Describes First Ultraviolet Imaging of Sun's Middle Corona

Video Credit: Courtesy of SwRI/NOAA A

A team of researchers from Southwest Research Institute (SwRI), NASA and the Max Planck Institute for Solar System Research (MPS) have discovered web-like plasma structures in the Sun’s middle corona. The researchers describe their innovative new observation method, imaging the middled corona in ultraviolet (UV) wavelength, in a new study published in Nature Astronomy. The findings could lead to a better understanding of the solar wind’s origins and its interactions with the rest of the solar system.

Since 1995, the U.S. National Oceanic and Atmospheric Administration has observed the Sun’s corona with the Large Angle and Spectrometric Coronagraph (LASCO) stationed aboard the NASA and European Space Agency Solar and Heliospheric Observatory (SOHO) spacecraft to monitor space weather that could affect the Earth. But LASCO has a gap in observations that obscures our view of the middle solar corona, where the solar wind originates.

Cities on asteroids? It could work—in theory

In what they deem a “wildly theoretical” paper, Rochester researchers imagine covering an asteroid in a flexible, mesh bag made of ultralight and high-strength carbon nanofibers as the key to creating human cities in space.
Illustration Credit: University of Rochester | Michael Osadciw

Rochester scientists use physics and engineering principles to show how asteroids could be future viable space habitats.

This past year, Jeff Bezos launched himself into space, while Elon Musk funded a space flight for a non-astronaut crew. Space collaborations between government and private entities, including Musk’s SpaceX and Bezos’s Blue Origin have become increasingly common. But with the recent emergence of the so-called “New Space” movement, aerospace companies are working to develop low-cost access to space for everyone, not only billionaires.

For a future beyond Earth, however, humans need places to accommodate homes, buildings, and other structures for millions of people to live and work.

Right now, space cities exist only in science fiction. But are space cities feasible in reality? And, if so, how?

According to new research from University of Rochester scientists, our future may lie in asteroids.

In what they deem a “wildly theoretical” paper published in the journal Frontiers in Astronomy and Space Sciences, the researchers, including Adam Frank, the Helen F. and Fred H. Gowen Professor of Physics and Astronomy, and Peter Miklavčič, a PhD candidate in mechanical engineering and the paper’s first author, outline a plan for creating large cities on asteroids.

Mysteriously bright flash is a black hole jet pointing straight toward Earth, astronomers say

Caption:Astronomers identified an extremely bright black hole jet, halfway across the universe, pointing straight toward Earth.
Illustration Credit: Dheeraj Pasham, Matteo Lucchini, and Margaret Trippe.

Earlier this year, astronomers were keeping tabs on data from the Zwicky Transient Facility, an all-sky survey based at the Palomar Observatory in California, when they detected an extraordinary flash in a part of the sky where no such light had been observed the night before. From a rough calculation, the flash appeared to give off more light than 1,000 trillion suns.

The team, led by researchers at NASA, Caltech, and elsewhere, posted their discovery to an astronomy newsletter, where the signal drew the attention of astronomers around the world, including scientists at MIT. Over the next few days, multiple telescopes focused on the signal to gather more data across multiple wavelengths in the X-ray, ultraviolet, optical, and radio bands, to see what could possibly produce such an enormous amount of light.

Now, the MIT astronomers along with their collaborators have determined a likely source for the signal. In a study appearing in Nature Astronomy, the scientists report that the signal, named AT 2022cmc, likely comes from a relativistic jet of matter streaking out from a supermassive black hole at close to the speed of light. They believe the jet is the product of a black hole that suddenly began devouring a nearby star, releasing a huge amount of energy in the process.

Most distant detection of a black hole swallowing a star

This artist’s impression illustrates how it might look when a star approaches too close to a black hole, where the star is squeezed by the intense gravitational pull of the black hole. Some of the star’s material gets pulled in and swirls around the black hole forming the disc that can be seen in this image. In rare cases, such as this one, jets of matter and radiation are shot out from the poles of the black hole. In the case of the AT2022cmc event, evidence of the jets was detected by various telescopes including the VLT, which determined this was the most distant example of such an event. 
Illustration Credit: ESO/M.Kornmesser

Earlier this year, the European Southern Observatory’s Very Large Telescope (ESO’s VLT) was alerted after an unusual source of visible light had been detected by a survey telescope. The VLT, together with other telescopes, was swiftly repositioned towards the source: a supermassive black hole in a distant galaxy that had devoured a star, expelling the leftovers in a jet. The VLT determined it to be the furthest example of such an event to have ever been observed. Because the jet is pointing almost towards us, this is also the first time it has been discovered with visible light, providing a new way of detecting these extreme events.

Stars that wander too close to a black hole are ripped apart by the incredible tidal forces of the black hole in what is known as a tidal disruption event (TDE). Approximately 1% of these cause jets of plasma and radiation to be ejected from the poles of the rotating black hole. In 1971, the black hole pioneer John Wheeler[1] introduced the concept of jetted-TDEs as “a tube of toothpaste gripped tight about its middle,” causing the system to “squirt matter out of both ends.”

Small asteroids are probably young

Simulation of the SCI impact. a) – c) Snapshots of the simulation at different times. At t = 1200s, the development of the crater is over. d) SCI crater on the asteroid Ryugu. The key characteristics of the observed crater, including the displacement of the boulders, are recreated in the simulation.
Credit: Courtesy of Martin Jutzi

The impact experiment conducted on the asteroid Ryugu by the Japanese Hayabusa2 mission which took place two years ago resulted in an unexpectedly large crater. With the use of simulations, a team led by the University of Bern and the National Center of Competence in Research (NCCR) PlanetS has recently succeeded in gaining new insights from the experiment regarding the formation and development of asteroids. These insights are also important for the DART mission of NASA.

The Hayabusa2 spacecraft was developed in order to study the history of the asteroid Ryugu, and collected samples and returned them to earth for laboratory analysis. The project participants are Dr. Martin Jutzi and Dr. Sabina Raducan, both from the Physical Institute of the University of Bern, Department for Space Research and Planetology (WP), and are members of the National Center of Competence in Research (NCCR) PlanetS. Under their leadership, in a study which has recently been published in Nature Communications, the team has presented new findings on the formation and development of asteroids.