Webb and Hubble Capture Detailed Views of DART Impact

For the first time, the NASA/ESA/CSA James Webb Space Telescope and the NASA/ESA Hubble Space Telescope have taken simultaneous observations of the same target.  These images, Hubble on left and Webb on the right, show observations of Dimorphos several hours after NASA’s Double Asteroid Redirection Test (DART) intentionally impacted the moonlet asteroid. It was the world’s first test of the kinetic impact technique using a spacecraft to deflect an asteroid by modifying its orbit.  Both Webb and Hubble observed the asteroid before and after the collision took place.  Scientists will use the combined observations from Hubble and Webb to gain knowledge about the nature of the surface of Dimorphos, how much material was ejected by the collision, how fast it was ejected, and the distribution of particle sizes in the expanding dust cloud.  In the coming months, scientists will also use Webb’s Mid-Infrared Instrument (MIRI) and Near-Infrared Spectrograph (NIRSpec) to observe Dimorphos further. Spectroscopic data will provide researchers with insight into the asteroid’s composition. Hubble will monitor Dimorphos ten more times over the next three weeks to monitor how the ejecta cloud expands and fades over time.  Hubble observations were conducted in one filter, WFC3/UVIS F350LP (assigned the color blue), while Webb observed at F070W (0.7 microns, assigned the color red). 
Credit: NASA, ESA, CSA, and STScI

Two of the great observatories, the NASA/ESA/CSA James Webb Space Telescope and the NASA/ESA Hubble Space Telescope, have captured views of a unique experiment to smash a spacecraft into a small asteroid. NASA’s Double Asteroid Redirection Test (DART) impact observations mark the first time that Webb and Hubble were used to simultaneously observe the same celestial target.

On 26 September 2022 at 13:14 CEST, DART intentionally crashed into Dimorphos, the asteroid moonlet in the double-asteroid system of Didymos. It was the world’s first test of the kinetic impact technique using a spacecraft to deflect an asteroid by modifying the object’s orbit. DART is a test for defending Earth against potential asteroid or comet hazards.

The observations are more than just an operational milestone for each telescope—there are also key science questions relating to the makeup and history of our solar system that researchers can explore when combining the capabilities of these observatories.

Mysterious ripples in the Milky Way were caused by a passing dwarf galaxy

Illustration: NASA JPL-Caltech R. Hurt (SSC Caltech)

Using data from the Gaia space telescope, a team led by researchers at Lund University in Sweden has shown that large parts of the Milky Way's outer disk vibrate. The ripples are caused by a dwarf galaxy, now seen in the constellation Sagittarius, that shook our galaxy as it passed by hundreds of millions of years ago.

Our cosmic home, the Milky Way, contains between 100 and 400 billion stars. Astronomers believe that the galaxy was born 13.6 billion years ago, emerging from a rotating cloud of gas composed of hydrogen and helium. Over billions of years, the gas then collected in a rotating disk where the stars, such as our sun, were formed.

In a new study published in Monthly Notices of the Royal Astronomical Society, the research team presents their findings about the stars in the outer regions of the galactic disk.

Astronomers detect hot gas bubble swirling around the Milky Way’s supermassive black hole

This shows a still image of the supermassive black hole Sagittarius A*, as seen by the Event Horizon Collaboration (EHT), with an artist’s illustration indicating where the modelling of the ALMA data predicts the hot spot to be and its orbit around the black hole. 
Credit: EHT Collaboration, ESO/M. Kornmesser (Acknowledgment: M. Wielgus)

Using the Atacama Large Millimeter/submillimeter Array (ALMA), astronomers have spotted signs of a ‘hot spot’ orbiting Sagittarius A*, the black hole at the centre of our galaxy. The finding helps us better understand the enigmatic and dynamic environment of our supermassive black hole.

“We think we're looking at a hot bubble of gas zipping around Sagittarius A* on an orbit similar in size to that of the planet Mercury, but making a full loop in just around 70 minutes. This requires a mind-blowing velocity of about 30% of the speed of light!” says Maciek Wielgus of the Max Planck Institute for Radio Astronomy in Bonn, Germany, who led the study published today in Astronomy & Astrophysics.

The observations were made with ALMA in the Chilean Andes — a radio telescope co-owned by the European Southern Observatory (ESO) — during a campaign by the Event Horizon Telescope (EHT) Collaboration to image black holes. In April 2017 the EHT linked together eight existing radio telescopes worldwide, including ALMA, resulting in the recently released first ever image of Sagittarius A. To calibrate the EHT data, Wielgus and his colleagues, who are members of the EHT Collaboration, used ALMA data recorded simultaneously with the EHT observations of Sagittarius A. To the team's surprise, there were more clues to the nature of the black hole hidden in the ALMA-only measurements.

Astronomers Unveil New – and Puzzling – Features of Mysterious Fast Radio Bursts

Artist's conception of Five-hundred-meter Aperture Spherical radio Telescope (FAST) in China.
Credit: Jingchuan Yu

Fast radio bursts (FRBs) are millisecond-long cosmic explosions that each produce the energy equivalent to the sun’s annual output. More than 15 years after the deep-space pulses of electromagnetic radio waves were first discovered, their perplexing nature continues to surprise scientists – and newly published research only deepens the mystery surrounding them.

In the Sept. 21 issue of the journal Nature, unexpected new observations from a series of cosmic radio bursts by an international team of scientists – including UNLV astrophysicist Bing Zhang – challenge the prevailing understanding of the physical nature and central engine of FRBs.

The cosmic FRB observations were made in late spring 2021 using the massive Five-hundred-meter Aperture Spherical radio Telescope (FAST) in China. The team, led by Heng Xu, Kejia Lee, Subo Dong from Peking University, and Weiwei Zhu from the National Astronomical Observatories of China, along with Zhang, detected 1,863 bursts in 82 hours over 54 days from an active fast radio burst source called FRB 20201124A.

“This is the largest sample of FRB data with polarization information from one single source”, said Lee.

Astro­physics: Star-child­hood shapes stel­lar evo­lu­tion

Tarantula Nebula: In this famous star-forming region in our neighboring galaxy, the Large Magellanic Cloud, many young stars are still in their molecular clouds, pictured by James Webb Space Telescope.
Hi-Res Zoomable Image
Credits: NASA, ESA, CSA, STScI, Webb ERO Production Team

In classical models of stellar evolution, so far little importance has been attached to the early evolution of stars. Thomas Steindl from the Institute of Astro- and Particle Physics at the University of Innsbruck now shows for the first time that the biography of stars is indeed shaped by their early stage. The study was published in Nature Communications.

From babies to teenagers: stars in their "young years" are a major challenge for science. The process of star formation is particularly complex and difficult to map in theoretical models. One of the few ways to learn more about the formation, structure or age of stars is to observe their oscillations. "Comparable to the exploration of the Earth's interior with the help of seismology, we can also make statements about their internal structure and thus also about the age of stars based on their oscillations" says Konstanze Zwintz. The astronomer is regarded as a pioneer in the young field of asteroseismology and heads the research group "Stellar Evolution and Asteroseismology" at the Institute for Astro- and Particle Physics at the University of Innsbruck. The study of stellar oscillations has evolved significantly in recent years because the possibilities for precise observation through telescopes in space such as TESS, Kepler, and James Webb have improved on many levels. These advances are now also shedding new light on decades-old theories of stellar evolution.

Chrysalis, the lost moon that gave Saturn its rings

Artistic rendering of the moon Chrysalis disintegrating in Saturn’s intense gravity field. The chunks of icy rock eventually collided and shattered into smaller pieces that became distributed in the thin ring we see today.
Image credit B. Militzer and NASA

Rings appear to be common around planets in the solar system, but the dramatic rings of Saturn have long puzzled astronomers, as has the steep tilt of the rings and the planet’s rotation axis relative to its orbit around the sun.

Scientists now show that the rings and the tilt are intimately linked, and that the key is a former moon of Saturn that was torn apart some 160 million years ago to form the rings. The researchers dubbed the lost moon Chrysalis because it blossomed into the rings much as a chrysalis transforms into a butterfly.

The new proposal for how Saturn became “Lord of the Rings” in our solar system and how Saturn got its axial tilt will be published this week in the journal Science. The lead author is Jack Wisdom, a professor of planetary science at the Massachusetts Institute of Technology (MIT), with key contributions from Burkhard Militzer at the University of California, Berkeley.

Militzer, UC Berkeley professor of earth and planetary science, was part of a team that in 2019 concluded that the rings of Saturn are relatively recent, having formed a mere 100 million years ago and perhaps even more recently. The planet itself is as old as the solar system, about 4.5 billion years. The rings could be debris left over from the tidal destruction of a former icy moon of Saturn or the remains of a comet that strayed too close to the planet.

New Evidence of Baby Planet in the Making

Artist's illustration of a small Saturn-like planet discovered in the system LkCa 15. The planet resides within dense rings of dust and gas that surround a bright yellow star. Material accumulates in a clump and arc-shape, about 60 degrees away from the planet. Note: This illustration is not to scale.
Credit: M.Weiss/Center for Astrophysics | Harvard & Smithsonian

Astronomers agree that planets are born in protoplanetary disks — rings of dust and gas that surround young, newborn stars. While hundreds of these disks have been spotted throughout the universe, observations of actual planetary birth and formation have proved difficult within these environments.

Now, astronomers at the Center for Astrophysics | Harvard & Smithsonian have developed a new way to detect these elusive newborn planets — and with it, "smoking gun" evidence of a small Neptune or Saturn-like planet lurking in a disk. The results are described today in The Astrophysical Journal Letters.

"Directly detecting young planets is very challenging and has so far only been successful in one or two cases," says Feng Long, a postdoctoral fellow at the Center for Astrophysics who led the new study. "The planets are always too faint for us to see because they’re embedded in thick layers of gas and dust."

Scientists instead must hunt for clues to infer a planet is developing beneath the dust.

Simulation helps in the search for the origin of cosmic radiation

The colorful lines show how cosmic radiation is deflected in magnetic fields. The white straight lines represent a large-scale magnetic field. In addition, small-scale magnetic fields not shown here act on the orbits of the particles (colorful lines).
Credit: RUB, Dr. Lukas Merten

The cosmic radiation seems to be all around us. That is exactly what makes it difficult to find their sources. It would be helpful if you could trace your way back through space. A new program helps with this.

An international research team has developed a computer program that can be used to simulate the transport of cosmic radiation through space. The scientists hope to be able to solve the puzzle about the sources of cosmic radiation. So far it is unknown which celestial objects emit the high-energy radiation that patterns the earth from space. In order to be able to explain experimental data, theoretical models are required; the new computer simulation can deliver this. A team of researchers from the Ruhr University Bochum (RUB) describes the software in the journal of Cosmology and Astroparticle Physics, published online on September 12, 2022.

Like a uniformly illuminated sky during the day

Since their discovery of 100 years, researchers have been trying to decipher where the cosmic radiation comes from. The problem: viewed from Earth, it looks like heaven by day with the naked eye: it is illuminated almost everywhere where you look. Because the light of the sun is scattered in the earth's atmosphere and is distributed evenly over the entire sky. Cosmic radiation is also scattered on its way to earth - through interactions with cosmic magnetic fields. Only a uniformly illuminated picture can be seen from the earth; the origin of the radiation remains hidden.

Dark Energy Camera Captures Bright, Young Stars Blazing Inside Glowing Nebula

NOIRLab, captures the star-forming nebula NGC 6357, which is located 8000 light-years away in the direction of the constellation Scorpius.
Hi-Res Zoomable Image
Credit: CTIO/NOIRLab/DOE/NSF/AURA  T.A. Rector (University of Alaska Anchorage/NSF’s NOIRLab), J. Miller (Gemini Observatory/NSF’s NOIRLab), M. Zamani & D. de Martin (NSF’s NOIRLab)

The 570-megapixel US Department of Energy-fabricated Dark Energy Camera at NOIRLab’s Cerro Tololo Inter-American Observatory in Chile is one of the most powerful tools in astronomy and astrophysics. To commemorate its first decade of discovery and exploration, NOIRLab has released a stunning image of the Lobster Nebula, a brilliant star-forming region located 8000 light-years from Earth in the direction of the constellation Scorpius. The image was unveiled at a conference highlighting DECam’s breakthrough science results.

The Dark Energy Camera (DECam) mounted on the Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory in Chile, a Program of NSF’s NOIRLab, is celebrating 10 years as one of the highest-performance, wide-field CCD imagers in the world.

To help commemorate DECam’s first decade of operation, NOIRLab has released a breathtaking image of the star-forming Lobster Nebula (NGC 6357), which is located about 8000 light-years from Earth in the direction of the constellation Scorpius. This image reveals bright, young stars surrounded by billowing clouds of dust and gas.

A thousand days of CHEOPS

Artist's impression of CHEOPS
Credit: ESA / ATG medialab

After a thousand days in orbit, the CHEOPS space telescope shows almost no signs of wear. Under these conditions, it could continue to reveal details of some of the most fascinating exoplanets for quite some time. CHEOPS is a joint mission by the European Space Agency (ESA) and Switzerland, under the aegis of the University of Bern in collaboration with the University of Geneva.

Since its launch from Europe's Spaceport in French Guiana, on December 18th, 2019, the CHEOPS telescope in Earth’s orbit has demonstrated its functionality and precision beyond expectations. During this time, it has revealed the characteristics of numerous fascinating planets beyond our Solar System (exoplanets) and has become a key instrument for astronomers in Europe and worldwide.

Could more of Earth’s surface host life?

There are varying degrees of orbital eccentricity around a central star.
Credit: NASA/JPL-Caltech

Of all known planets, Earth is as friendly to life as any planet could possibly be — or is it? If Jupiter’s orbit changes, a new study shows Earth could be more hospitable than it is today.

When a planet has a perfectly circular orbit around its star, the distance between the star and the planet never changes. Most planets, however, have "eccentric" orbits around their stars, meaning the orbit is oval-shaped. When the planet gets closer to its star, it receives more heat, affecting the climate.

Using detailed models based on data from the solar system as it is known today, UC Riverside researchers created an alternative solar system. In this theoretical system, they found that if gigantic Jupiter’s orbit were to become more eccentric, it would in turn induce big changes in the shape of Earth’s orbit.

“If Jupiter’s position remained the same, but the shape of its orbit changed, it could actually increase this planet’s habitability,” said Pam Vervoort, UCR Earth and planetary scientist and lead study author.

Between zero and 100 degrees Celsius, the Earth’s surface is habitable for multiple known life forms. If Jupiter pushed Earth’s orbit to become more eccentric, parts of the Earth would sometimes get closer to the sun. Parts of the Earth’s surface that are now sub-freezing would get warmer, increasing temperatures in the habitable range.

Two new rocky worlds around an ultra-cool star

The telescopes of the SPECULOOS Southern Observatory gaze out into the stunning night sky over the Atacama Desert, Chile.
Credit: ESO/ P. Horålek

An international research team, with the participation of the University of Bern and the National Centre of Competence in Research (NCCR) PlanetS, discovered two "super-Earth" exoplanets. One is located at just the right distance from its star to potentially hold liquid water on its surface.

Most of the planets that have been discovered around other stars – also known as exoplanets – are bad candidates for life as we know it. They are either scorching hot or freezing cold, and the majority consist of nothing but gas. Relatively small terrestrial planets, like our Earth, are difficult to detect. Only a handful are known that receive just the right amount of radiation from their star to allow liquid water on their surface. The reported discovery of a promising candidate for such a world, made by a team of researchers with the participation of the University of Bern and the National Centre of Competence in Research (NCCR) PlanetS, is therefore a significant one. The team published their results in the journal Astronomy & Astrophysics. (As of this posting not yet released)

X-shaped radio galaxies might form more simply than expected

When astronomers use radio telescopes to gaze into the night sky, they typically see elliptical-shaped galaxies, with twin jets blasting from either side of their central supermassive black hole. But every once in a while, — less than 10% of the time — astronomers might spot something special and rare: An X-shaped radio galaxy, with four jets extending far into space.

Although these mysterious X-shaped radio galaxies have confounded astrophysicists for two decades, a new Northwestern University study sheds new insight into how they form — and its surprisingly simple. The study also found that X-shaped radio galaxies might be more common than previously thought.

The study was published in the Astrophysical Journal Letters. It marks the first large-scale galaxy accretion simulation that tracks the galactic gas far from the supermassive black hole all the way toward it.

Simple conditions lead to messy result

Using new simulations, the Northwestern astrophysicists implemented simple conditions to model the feeding of a supermassive black hole and the organic formation of its jets and accretion disk. When the researchers ran the simulation, the simple conditions organically and unexpectedly led to the formation of an X-shaped radio galaxy.

An extrasolar world covered in water?

Artistic rendition of the exoplanet TOI-1452 b, a small planet that may be entirely covered in a deep ocean.
Credit: Benoit Gougeon, Université de Montréal.

An international team of researchers led by Charles Cadieux, a Ph.D. student at the Université de Montréal and member of the Institute for Research on Exoplanets (iREx), has announced the discovery of TOI-1452 b, an exoplanet orbiting one of two small stars in a binary system located in the Draco constellation about 100 light-years from Earth.

The exoplanet is slightly greater in size and mass than Earth and is located at a distance from its star where its temperature would be neither too hot nor too cold for liquid water to exist on its surface. The astronomers believe it could be an “ocean planet,” a planet completely covered by a thick layer of water, similar to some of Jupiter’s and Saturn’s moons.

In an article published in The Astronomical Journal, Cadieux and his team describe the observations that elucidated the nature and characteristics of this unique exoplanet.

“I’m extremely proud of this discovery because it shows the high caliber of our researchers and instrumentation,” said René Doyon, Université de Montréal Professor and Director of iREx and of the Observatoire du Mont-Mégantic (OMM). “It is thanks to the OMM, a special instrument designed in our labs called SPIRou, and an innovative analytic method developed by our research team that we were able to detect this one-of-a-kind exoplanet.”

Surprising details leap out in sharp new James Webb Space Telescope images of Jupiter

Image 1 This July 27 image of Jupiter taken by the Near-Infrared Camera on the new James Webb Space Telescope is artificially colored to emphasize stunning details of the planet: auroral emission from ionized hydrogen at both the north and south poles (red); high-altitude hazes (green) that swirl around the poles; and light reflected from the deeper main cloud (blue). The Great Red Spot, the equatorial region and compact cloud regions appear white or reddish-white; regions with little cloud cover appear as dark ribbons north of the equatorial region.
Resized Image using AI by SFLORG
Additional Below
Image credit: NASA, European Space Agency, Jupiter Early Release Science team. Image processing: Judy Schmidt

The latest images of Jupiter from the James Webb Space Telescope (JWST) are stunners.

Captured on July 27, the infrared images — artificially colored to make specific features stand out — show fine filigree along the edges of the colored bands and around the Great Red Spot and also provide an unprecedented view of the auroras over the north and south poles.

One wide-field image presents a unique lineup of the planet, its faint rings and two of Jupiter’s smaller satellites — Amalthea and Adrastea — against a background of galaxies.

“We’ve never seen Jupiter like this. It’s all quite incredible,” said planetary astronomer Imke de Pater, professor emerita of the University of California, Berkeley, who led the scientific observations of the planet with Thierry Fouchet, a professor at the Paris Observatory. “We hadn’t really expected it to be this good, to be honest. It’s really remarkable that we can see details on Jupiter together with its rings, tiny satellites and even galaxies in one image.”

De Pater, Fouchet and their team released the images today (Aug. 22) as part of the telescope’s Early Release Science program.

Breaking in a New Planet

Brandon Johnson, an expert in impact crater dynamics, surrounded by some of his favorite research subjects: Mercury, Mars and the moon.
Credit: Purdue University | Rebecca McElhoe

The harder you hit something – a ball, a walnut, a geode – the more likely it is to break open. Or, if not break open, at least lose a little bit of its structural integrity, the way baseball players pummel new gloves to make them softer and more flexible. Cracks, massive or tiny, form and bear a silent, permanent witness to the impact.

Studying how those impacts affect planetary bodies, asteroids, moons and other rocks in space helps planetary scientists including Brandon Johnson, associate professor, and Sean Wiggins, postdoctoral researcher, in the College of Science’s Department of Earth, Atmospheric, and Planetary Sciences at Purdue University, understand extraplanetary geology, especially where to look for precious matter including water, ice and even, potentially, microbial life. A YouTube video is available online.

Every solid body in the solar system is constantly pummeled by impacts, both large and small. Even on Earth, every single spot has been affected by at least three big impacts. Using the moon as a test subject, Johnson, Wiggins and their team set out to quantify the relationship between impacts and a planet’s porosity.

New Technology Sharpens Images of Black Holes

The emission from M87 has now been resolved into a bright, thin ring (orange colormap), arising from the infinite sequence of additional images of the emission region, and the more diffuse primary image, produced by the photons that come directly toward Earth (in blue contours). When viewed at the imaging resolution of the Event Horizon Telescope, the two components blur together. However, by separately searching for the thin ring, it is possible to sharpen the view of M87, isolating the fingerprint of strong gravity.
Credit: Broderick et al. 2022, ApJ, 935, 61

When scientists unveiled humanity’s historic first image of a black hole in 2019 — depicting a dark core encircled by a fiery aura of material falling toward it — they believed even richer imagery and insights were waiting to be teased out of the data.

Simulations predict that, obscured by that bright orange glow, there should exist a thin, bright ring of light created by photons flung around the back of the black hole by its intense gravity.

Now, a team of researchers has combined theoretical predictions and sophisticated imaging algorithms to “remaster” the original imagery of the supermassive black hole at the center of the galaxy M87*, first captured by the Event Horizon Telescope (EHT) in 2019. Their findings, published today in The Astrophysical Journal, are consistent with theoretical predictions and offer new ways to explore these mysterious objects, which are believed to reside at the hearts of most galaxies.

"The approach we took involved leveraging our theoretical understanding of how these black holes look to build a customized model for the EHT data," says Dominic Pesce, a study co-author based at the Center for Astrophysics | Harvard & Smithsonian and member of the EHT collaboration. "Our model decomposes the reconstructed image into the two pieces that we care most about, so that we can study both pieces individually rather than blended together."

Scientists Take Another Theoretical Step to Uncovering the Mystery of Dark Matter, Black Holes

A star (orange) that gets close to a supermassive black hole (black) can be tidally disrupted by the black hole’s strong gravitational pull. According to a new study, if ultra-light bosons exist (purple), they can affect the spin of the black hole, which in turn affects the rate at which tidal disruption events occur.
 Credit: Peizhi Du

Much of the matter in the universe remains unknown and undefined, yet theoretical physicists continue to gain clues to the properties of dark matter and black holes. A study by a team of scientists including three from Stony Brook University proposes a novel method to search for new particles not currently contained in the standard model of particle physics. Their method, published in Nature Communications, could shed light on the nature of dark matter.

The three Stony Brook authors include Rouven Essig, PhD, Professor in the C. N. Yang Institute for Theoretical Physics (YITP); Rosalba Perna, PhD, Professor in the Department of Physics and Astronomy, and Peizhi Du, PhD, postdoctoral researcher at the YITP.

Stars that pass close to the supermassive black holes located in the center of galaxies can be disrupted by tidal forces, leading to flares that are observed as bright transient events in sky surveys. The rate for these events to occur depends on the black hole spins, which in turn can be affected by ultra-light bosons (hypothetical particles with minute masses) due to superradiance. The research team performed a detailed analysis of these effects, and they discovered that searches for stellar tidal-disruptions have the potential to uncover the existence of ultra-light bosons.

A gold inflatable Martian House designed to withstand life on Mars has landed in Bristol

The exterior of the Martian House
Credit: Luke O’Donovan

A two-story house designed for future life on Mars has landed on M Shed Square in Bristol, UK as part of an ongoing public art project, Building a Martian House.

The brainchild of local artists and Watershed Pervasive Media Studio residents Ella Good and Nicki Kent, the project has been designed over several years and brought together space scientists, world renowned architects, engineers, designers, school children and the public, to explore how considering future life on Mars, a planet with low power, zero emissions and zero waste, can inspire us to think creatively about how we can live more sustainably on earth and reassess our relationship with consumerism.

A team led by Hugh Broughton Architects, world experts in creating buildings for extreme environments including the Halley VI British Antarctic Research Station, working in partnership with design studio Pearce+, developed the design of the house.

The design team worked alongside space science and engineering experts Professor Lucy Berthoud, Dr Robert Myhill and Professor James Norman from the University of Bristol. A cohort of construction companies led by Southern Construction Framework generously donated their time and expertise to bring the project to life and funding has been provided by the Edward Marshall Trust.

Supernova remnant is source of extreme cosmic particles

Astronomers have long sought the launch sites for some of the highest energy protons in our galaxy. Now, a study using 12 years of data from NASA’s Fermi Gamma-ray Space Telescope confirms that a remnant of a supernova, or star explosion, is just such a place, solving a decade-long cosmic mystery.

Previously, Fermi has shown that the shock waves of exploded stars boost particles to speeds comparable to that of light. Called cosmic rays, these particles mostly take the form of protons, but can include atomic nuclei and electrons. Because they all carry an electric charge, their paths become scrambled as they whisk through our galaxy’s magnetic field, which masks their origins. But when these particles collide with interstellar gas near the supernova remnant, they produce a telltale glow in gamma rays—the highest-energy light there is.

“Theorists think the highest-energy cosmic ray protons in the Milky Way reach a million billion electron volts, or PeV (for peta-electron-volt) energies,” says Ke Fang, an assistant professor of physics at the University of Wisconsin–Madison’s Wisconsin IceCube Particle Astrophysics Center. “The precise nature of their sources, which we call PeVatrons, has been difficult to pin down.”