First results from ESO telescopes on the aftermath of DART’s asteroid impact

This series of images, taken with the MUSE instrument on ESO’s Very Large Telescope, shows the evolution of the cloud of debris that was ejected when NASA’s DART spacecraft collided with the asteroid Dimorphos.  The first image was taken on 26 September 2022, just before the impact, and the last one was taken almost one month later on 25 October. Over this period several structures developed: clumps, spirals, and a long tail of dust pushed away by the Sun’s radiation. The white arrow in each panel marks the direction of the Sun.  Dimorphos orbits a larger asteroid called Didymos. The white horizontal bar corresponds to 500 kilometers, but the asteroids are only 1 kilometer apart, so they can’t be discerned in these images.  The background streaks seen here are due to the apparent movement of the background stars during the observations while the telescope was tracking the asteroid pair. 
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Image Credit: ESO/Opitom et al.

Using ESO’s Very Large Telescope (VLT), two teams of astronomers have observed the aftermath of the collision between NASA’s Double Asteroid Redirection Test (DART) spacecraft and the asteroid Dimorphos. The controlled impact was a test of planetary defense, but also gave astronomers a unique opportunity to learn more about the asteroid’s composition from the expelled material.

On 26 September 2022 the DART spacecraft collided with the asteroid Dimorphos in a controlled test of our asteroid deflection capabilities. The impact took place 11 million kilometers away from Earth, close enough to be observed in detail with many telescopes. All four 8.2-metre telescopes of ESO’s VLT in Chile observed the aftermath of the impact, and the first results of these VLT observations have now been published in two papers.

”Asteroids are some of the most basic relics of what all the planets and moons in our Solar System were created from,” says Brian Murphy, a PhD student at the University of Edinburgh in the UK and co-author of one of the studies. Studying the cloud of material ejected after DART’s impact can therefore tell us about how our Solar System formed. “Impacts between asteroids happen naturally, but you never know it in advance,” continues Cyrielle Opitom, an astronomer also at the University of Edinburgh and lead author of one of the articles. “DART is a really great opportunity to study a controlled impact, almost as in a laboratory.”

‘Terminator zones’ on distant planets could harbor life

Some exoplanets have one side permanently facing their star while the other side is in perpetual darkness. The ring-shaped border between these permanent day and night regions is called a “terminator zone.” In a new paper in The Astrophysical Journal, physics and astronomy researchers at UC Irvine say this area has the potential to support extraterrestrial life.
Illustration Credit: Ana Lobo / University of California, Irvine

In a new study, University of California, Irvine astronomers describe how extraterrestrial life has the potential to exist on distant exoplanets inside a special area called the “terminator zone,” which is a ring on planets that have one side that always faces its star and one side that is always dark.

“These planets have a permanent day side and a permanent night side,” said Ana Lobo, a postdoctoral researcher in the UCI Department of Physics & Astronomy who led the new work, which was just published in The Astrophysical Journal. Lobo added that such planets are particularly common because they exist around stars that make up about 70 percent of the stars seen in the night sky – so-called M-dwarf stars, which are relatively dimmer than our sun.

The terminator is the dividing line between the day and night sides of the planet. Terminator zones could exist in that “just right” temperature zone between too hot and too cold.

“You want a planet that’s in the sweet spot of just the right temperature for having liquid water,” said Lobo, because liquid water, as far as scientists know, is an essential ingredient for life.

On the dark sides of terminator planets, perpetual night would yield plummeting temperatures that could cause any water to be frozen in ice. The side of the planet always facing its star could be too hot for water to remain in the open for long.

Scientists have new tool to estimate how much water might be hidden beneath a planet’s surface

Exoplanets similar to Earth, artist concept.
Image Credit: NASA

Scientists from the University of Cambridge now have a way to estimate how much water a rocky planet can store in its subterranean reservoirs. It is thought that this water, which is locked into the structure of minerals deep down, might help a planet recover from its initial fiery birth.

The researchers developed a model that can predict the proportion of water-rich minerals inside a planet. These minerals act like a sponge, soaking up water which can later return to the surface and replenish oceans. Their results could help us understand how planets can become habitable following intense heat and radiation during their early years.

Planets orbiting M-type red dwarf stars — the most common star in the galaxy — are thought to be one of the best places to look for alien life. But these stars have particularly tempestuous adolescent years — releasing intense bursts of radiation that blast nearby planets and bake off their surface water.

Could Space Dust Help Protect the Earth from Climate Change?

Illustration Credit: Ben Bromley/University of Utah

On a cold winter day, the warmth of the Sun is welcome. Yet as humanity emits more greenhouse gases, the Earth's atmosphere traps more and more of the Sun's energy, which steadily increases the Earth's temperature. One strategy for reversing this trend is to intercept a fraction of sunlight before it reaches our planet.

For decades, scientists have considered using screens or other objects to block just enough of the Sun’s radiation — between 1 or 2 percent — to mitigate the effects of global warming. Now, a new study led by scientists at the Center for Astrophysics | Harvard & Smithsonian and the University of Utah explores the potential of using dust to shield sunlight.

The paper, published today in the journal PLOS Climate, describes different properties of dust particles, quantities of dust and the orbits that would be best suited for shading Earth. The team found that launching dust from Earth to a way station at the "Lagrange Point" between Earth and the Sun would be most effective but would require an astronomical cost and effort.

The team proposes moondust as an alternative, arguing that lunar dust launched from the Moon could be a low-cost and effective way to shade the Earth.

Simulations show aftermath of black hole collision

New simulations of two black holes colliding near the speed of light reveal the mysterious physics of what one astrophysicist calls "one of the most violent events you can imagine in the universe."

"It's a bit of a crazy thing to blast two black holes head-on very close to the speed of light," said Thomas Helfer, a postdoctoral fellow at Johns Hopkins University who produced the simulations. "The gravitational waves associated with the collision might look anticlimactic, but this is one of the most violent events you can imagine in the universe."

The work, which appears today in Physical Review Letters, is the first detailed look at the aftermath of such a cataclysmic clash, and shows how a remnant black hole would form and send gravitational waves through the cosmos.

Black hole mergers are one of the few events in the universe energetic enough to produce detectable gravitational waves, which carry energy produced by massive cosmic collisions. Like ripples in a pond, these waves flow through the universe distorting space and time. But unlike waves traveling through water, they are extremely tiny, and propagate through "spacetime," the mind-bending concept that combines the three dimensions of space with the idea of time.

NASA's Chandra Discovers Giant Black Holes on Collision Course

NASA’s Chandra X-ray Observatory helped identify two pairs of dwarf galaxies on track to merge.  Dwarf galaxies, which are at least about 20 times less massive than the Milky Way, likely formed larger galaxies through collisions in the early Universe.  These newly-discovered merging dwarf galaxies can be used as analogs for more distant ones that are too faint to observe.  The dwarf galaxies are on collision courses and are found in the galaxy clusters Abell 133 and Abell 1758S.
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Image Credit: X-ray: NASA/CXC/Univ. of Alabama/M. Micic et al.; Optical: International Gemini Observatory/NOIRLab/NSF/AURA

Astronomers have discovered the first evidence for giant black holes in dwarf galaxies on a collision course. This result from NASA’s Chandra X-ray Observatory has important ramifications for understanding how the first wave of black holes and galaxies grew in the early universe.

Collisions between the pairs of dwarf galaxies identified in a new study have pulled gas towards the giant black holes they each contain, causing the black holes to grow. Eventually the likely collision of the black holes will cause them to merge into much larger black holes. The pairs of galaxies will also merge into one.

Scientists think the universe was awash with small galaxies, known as “dwarf galaxies,” several hundred million years after the big bang. Most merged with others in the crowded, smaller volume of the early universe, setting in motion the building of larger and larger galaxies now seen around the nearby universe.

Meteorite crater discovered in French winery

The “Trou du Météore": The crater at the “Domaine du Météore" winery really was caused by a meteorite impact.
Photo Credit: Frank Brenker, Goethe University Frankfurt

With the aim of creating an appealing brand, the name of the “Domaine du Météore" winery near the town of Béziers in Southern France points to a local peculiarity: one of its vineyards lies in a round, 200-meter-wide depression that resembles an impact crater. By means of rock and soil analyses, scientists led by cosmochemist Professor Frank Brenker from Goethe University Frankfurt have now established that the crater was indeed once formed by the impact of an iron-nickel meteorite. In doing so, they have disproved a scientific opinion almost 60 years old, because of which the crater was never examined more closely from a geological perspective.

Countless meteorites have struck Earth in the past and shaped the history of our planet. It is assumed, for example, that meteorites brought with them a large part of its water. The extinction of the dinosaurs might also have been triggered by the impact of a very large meteorite. 

Meteorite craters that are still visible today are rare because most traces of the celestial bodies have long since disappeared again. This is due to erosion and shifting processes in the Earth's crust, known as plate tectonics. The “Earth Impact Database" lists just 190 such craters worldwide. In the whole of Western Europe, only three were previously known: Rochechouart in Aquitaine, France, the Nördlinger Ries between the Swabian Alb and the Franconian Jura, and the Steinheim Basin near Heidenheim in Baden-Württemberg (both in Germany). Thanks to millions of years of erosion, however, for laypersons the three impact craters are hardly recognizable as such.

On the track of the big bang: The most sensitive detector for measuring radioactivity is now in dresden

Prof. Kai Zuber (right) and Steffen Turkat
Photo Credit: Courtesy of Technische Universität Dresden

The "Felsenkeller" underground laboratory in Dresden now hosts the most sensitive setup for measuring radioactivity in Germany and one of the most sensitive setups in the world. With the new detector, researchers at the Technische Universität Dresden and the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) will in future be working at the highest international level on some of the most exciting questions in astrophysics, such as dark matter, stars or the Big Bang.

What is dark matter? What are neutrinos all about? How do stars work and what was actually going on in the universe in the first minutes after the Big Bang? To answer these questions, you need very sensitive detectors and a lot of skill. Only a few laboratories in the world have been able to perform such sensitive measurements so far. Recently, however, an ultra-sensitive detector has been set up in Germany, which will enable researchers to find answers to these questions in the future.

After long development work, researchers from the Institute for Nuclear and Particle Physics (Technische Universität Dresden) and the Institute for Radiation Physics (HZDR) have now put the setup into operation in the underground laboratory "Felsenkeller" Dresden. From now on, they will be able to analyze samples of substances and materials with radioactivity in the range of 100 microbequerels, in other words, samples with 100 million times less radioactivity than is present in the human body. This puts the measurement setup in the Felsenkeller laboratory among the world's most sensitive measuring instruments for radioactivity.

Unknown class of water-rich asteroids identified

Dwarf planet Ceres.
Image Credit: NASA / JPL-Caltech / UCLA / MPS / DLR / IDA / Justin Cowart

Small planets originate from the edge of our Solar System

New astronomical measurements in the infrared range have led to the identification of a heretofore unknown class of asteroids. An international research team including geoscientists from Heidelberg University has succeeded in characterizing these small planets using infrared spectroscopy. They are located in the asteroid belt between Mars and Jupiter and are – similar to the dwarf planet Ceres – rich in water. According to computer models, complex dynamic processes shifted these asteroids from the outer regions of our Solar System into today’s asteroid belt shortly after their creation.

With an equatorial diameter of approximately 900 kilometers, the dwarf planet Ceres is the largest object in the asteroid belt between Mars and Jupiter. Many other small planets orbit in this region as well. “These are the remains of the building materials from which the planets of our Solar System were created four and a half billion years ago. In these small bodies and their fragments, the meteorites, we find numerous relics that point directly to the process of planet formation,” explains Prof. Dr Mario Trieloff from the Institute of Earth Sciences of Heidelberg University. The current study shows that the small astronomical bodies originate from all regions of the early Solar System. By means of small bodies from the outer Solar System, water could have reached the still growing Earth in the form of asteroids, because the building blocks of the planets in the inner Solar System tended to be arid, according to Prof. Trieloff, who heads up the Geo- and Cosmochemistry research group.

Scientists find first observational evidence linking black holes to dark energy

Artist’s impression of a supermassive black hole. Cosmological coupling allows black holes to grow in mass without consuming gas or stars.
Image Credit: UH Manoa

Searching through existing data spanning 9 billion years, a University of Michigan physicist and colleagues have uncovered the first evidence of “cosmological coupling”—a newly predicted phenomenon in Einstein’s theory of gravity, possible only when black holes are placed inside an evolving universe.

Gregory Tarlé, U-M professor of physics, and researchers from the University of Hawaii and other institutions across nine countries studied supermassive black holes at the heart of ancient and dormant galaxies to develop a description of them that agrees with observations from the past decade. Their findings are published in two journal articles, one in The Astrophysical Journal and the other in The Astrophysical Journal Letters.

The first study found that these black holes gain mass over billions of years in a way that can’t easily be explained by standard galaxy and black hole processes, such as mergers or accretion of gas. According to the second paper, the growth in mass of these black holes matches predictions for black holes that not only cosmologically couple, but also enclose vacuum energy—material that results from squeezing matter as much as possible without breaking Einstein’s equations, thus avoiding a singularity.

Four classes of planetary systems

Artist impression of the four classes of planetary system architecture. A new architecture framework allows researchers to study an entire planetary system at the systems level. If the small planets within a system are close to the star and massive planets further away, such systems have ‘Ordered’ architecture. Conversely, if the mass of the planets in a system tends to decrease with distance to the star these systems are ‘Anti-Ordered’. If all planets in a system have similar masses, then the architecture of this system is ‘Similar’. ‘Mixed’ planetary systems are those in which the planetary masses show large variations. Research suggests that planetary systems which have the same architecture class have common formation pathways.
Illustration Credit: © NCCR PlanetS / Tobias Stierli

Astronomers have long been aware that planetary systems are not necessarily structured like our solar system. Researchers from the Universities of Bern and Geneva, as well as from the National Centre of Competence in Research PlanetS, have now shown for the first time that there are in fact four types of planetary systems. This classification will allow scientists to study planetary systems as a whole and to compare them with other systems. The results can be found in the journal Astronomy and Astrophysics.

In our solar system, everything seems to be in order: The smaller rocky planets, such as Venus, Earth or Mars, orbit relatively close to our star. The large gas and ice giants, such as Jupiter, Saturn or Neptune, on the other hand, move in wide orbits around the sun. In two studies published in the scientific journal Astronomy & Astrophysics, researchers from the Universities of Bern and Geneva and the National Centre of Competence in Research (NCCR) PlanetS show that our planetary system is quite unique in this respect. 

Spokes move along Saturn's rings

Spokes move along Saturn's rings
Seven Hubble Space Telescope images, each taken about four minutes apart, are stitched together to show "spoke" features rotating around Saturn. The puzzling, transient features have defied easy characterization. Their rotation rate does not quite match up with the rotation of the rings or of the planet's magnetic field. The spokes are known to appear during the period leading up to and following the planet's equinox. With the northern hemisphere autumnal equinox approaching on May 6, 2025, scientists are hoping new observations by Hubble will help them to put the clues together and solve the spoke mystery—what are they, and why do they form? Hubble observations will be compared with those made by NASA's Cassini spacecraft in the period surrounding Saturn's last equinox, in 2009. With the Cassini mission completed, Hubble's annual observations of Saturn as part of its Outer Planet Atmospheres Legacy (OPAL) program will be crucial to studying and better understanding this dynamic world.
Credits: SCIENCE: NASA, ESA, Amy Simon (NASA-GSFC) ANIMATION: Alyssa Pagan (STScI)

New images of Saturn from NASA's Hubble Space Telescope herald the start of the planet's "spoke season" surrounding its equinox, when enigmatic features appear across its rings. The cause of the spokes, as well as their seasonal variability, has yet to be fully explained by planetary scientists.

Like Earth, Saturn is tilted on its axis and therefore has four seasons, though because of Saturn's much larger orbit, each season lasts approximately seven Earth years. Equinox occurs when the rings are tilted edge-on to the Sun. The spokes disappear when it is near summer or winter solstice on Saturn. (When the Sun appears to reach either its highest or lowest latitude in the northern or southern hemisphere of a planet.) As the autumnal equinox of Saturn's northern hemisphere on May 6, 2025, draws near, the spokes are expected to become increasingly prominent and observable.

Breakthrough laboratory confirmation of key theory behind the formation of planets, stars and supermassive black holes

Pillars of Creation: By combining images of the iconic Pillars of Creation from two cameras aboard NASA’s James Webb Space Telescope, the universe has been framed in its glory. The pillars are the vast clouds of dust and gas in the foreground that swirl around and form celestial bodies. 
Hi-Res Zoomable Image
Photo Credit: JWST/NASA

The first laboratory realization of the longstanding but never-before confirmed theory of the puzzling formation of planets, stars and supermassive black holes by swirling surrounding matter has been produced at the Princeton Plasma Physics Laboratory (PPPL). This breakthrough confirmation caps more than 20 years of experiments at PPPL, which is based at Princeton University.

The puzzle arises because matter orbiting around a central object does not simply fall into it, due to what is called the conservation of angular momentum that keeps planets and the rings of Saturn from tumbling from their orbits. That’s because the outward centrifugal force balances out the inward pull of gravity on the orbiting matter. However, the clouds of dust and plasma called accretion disks that swirl around and collapse into celestial bodies do so in defiance of the conservation of angular momentum.    

The solution to this puzzle, a theory known as the Standard Magnetorotational Instability (SMRI), was first proposed in 1991 by University of Virginia theorists Steven Balbus and John Hawley. They built on the fact that in a fluid that conducts electricity, whether the fluid be plasma or liquid metal, magnetic fields behave like springs connecting different sections of the fluid. This allows ubiquitous Alfvén waves, named after Nobel Prize winner Hannes Alfvén, to create a turbulent back-and-forth force between the inertia of the swirling fluid and the springiness of the magnetic field, causing angular momentum to be transferred between different sections of the disk.

The moon is too hot and too cold; now it could be just right for humans, thanks to newly available science

Issam Mudawar’s research on heat transfer could enable space habitats to be built in extreme environments like the moon.
Photo Credit: Purdue University / John Underwood

With temperatures on the moon ranging from minus 410 to a scorching 250 degrees Fahrenheit, it’s an understatement to say that humans will need habitats with heat and air conditioning to survive there long term.

But heating and cooling systems won’t be effective enough to support habitats for lunar exploration or even longer trips to Mars without an understanding of what reduced gravity does to boiling and condensation. Engineers haven’t been able to crack this science – until now.

“Every refrigerator, every air conditioning system we have on Earth involves boiling and condensation. Those same mechanisms are also prevalent in numerous other applications, including steam power plants, nuclear reactors and both chemical and pharmaceutical industries,” said Issam Mudawar, Purdue University’s Betty Ruth and Milton B. Hollander Family Professor of Mechanical Engineering. “We have developed over a hundred years’ worth of understanding of how these systems work in Earth’s gravity, but we haven’t known how they work in weightlessness.”

A team of engineers at Purdue led by Mudawar, who is collaborating with NASA’s Glenn Research Center in Cleveland, has spent 11 years developing a facility to investigate these phenomena.

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.