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Scientists study 3,000 supernovas and discover that dark energy may be evolving

A catalog of almost 3,000 white dwarfs that exploded as type Ia supernovas after overfeeding on companion stars indicates that dark energy, the mysterious force accelerating the expansion of the universe, is changing over time.

The discovery, in conjunction with data from the Dark Energy Survey (DES), backs results revealed from the Dark Energy Spectroscopic Instrument (DESI) published in 2024 that suggested dark energy's influence is weakening.

That means that the team's research doesn't just involve the most comprehensive catalog of type Ia supernovas; it presents the clearest picture yet of the evolution of the universe and the influence of dark energy.

"We've rebuilt 3 decades of astronomical observations into a single, consistent framework," team member Ryan Camilleri of the University of Queensland said in a statement."We combined our data with other cosmic measurements, including relic light from the Big Bang and maps of how galaxies are distributed through space.

"Instead of confirming the standard model of cosmology, which assumes dark energy is fixed and unchanging, we have more evidence that dark energy may change over time."

How do exploding white dwarfs tell us about dark energy?

White dwarfs are the smoldering stellar remnants that are left over when stars with around the mass of the sun exhaust the fuel for nuclear fusion in their cores. This ends the outward pressure that supports a star against its own gravity, meaning the star's core collapses as the outer layers are shed. The core becomes a white dwarf, and for single stars, that is the end. But around 50% of sun-sized stars have a binary companion, and this can lead to renewed activity and a change in the star's fate.

If the white dwarf and its companion are close enough together, the dead star begins stripping away the outer layers of its companion. As this material builds on the white dwarf, it pushes the stellar remnant's mass over the so-called Chandrasekhar limit, allowing it to go supernova.

These cosmic explosions are called type Ia supernovas, and their light output is so uniform that these events are referred to as standard candles. They are of vital importance because measuring how their light has been redshifted as it travels means type Ia supernovas can be used to measure cosmic distances.

"Over the years we've learned a lot more about how supernovae behave so we've been able to go back and apply that improved understanding to older data," Camilleri said. "Extensive work has been done to link observations from different telescopes with different capacities and take into account issues such as cosmic dust and galaxy mass which can affect the light coming from a supernova.

"We also incorporated more subtle effects such as gravitational lensing, which is the bending and magnification of light around large objects as it travels from a supernova to Earth."

Two blue

Two "fans" representing DESI observations above and below the plane of the Milky Way (Image credit: DESI Collaboration/DOE/KPNO/NOIRLab/NSF/AURA/R. Proctor/ Robert Lea (created with Canva))

Combined with the 2024 results from DESI, this research could change our idea of what dark energy actually is.

"Our supernova data from DES in 2024 first showed hints that dark energy may be time-varying, and this new compilation also sees a deviation from the standard model, although in a slightly different direction," Davis said. "Similarly, results from DESI found hints of variations in dark energy in its surveys of relic sound waves from the early universe.

"So, two completely independent measurements have found hints of time variation in dark energy, challenging the standard model that dark energy doesn't change."

Davis added that, as well as revealing what dark energy actually is, this research may also hold the clue to explaining how gravity and quantum physics fit together. While quantum physics (the best theory we have of how the universe operates at subatomic scales) and Einstein's theory of general relativity (our best picture of gravity) have been highly successful in their own rights, scientists have so far been unable to unite them. In other words, there is no theory of quantum gravity.

“We know these two theories are each immensely successful in their own realms, so if we can figure out how to put them together, that would be a huge step in theoretical physics," Davis continued.

This effort will receive a boost when data is added to the team's already comprehensive type Ia supernova catalog. This will include observations from the Dark Energy Bedrock All-Sky Supernova program (DEBASS), which is detecting hundreds more local supernovas than even the DES survey.

The team's results are available on the repository site arXiv.

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Mercury is shrinking faster than we thought. What’s going on inside of it?

Wrinkles on the surface of Mercury have revealed that the closest planet to the sun is shrinking faster than scientists thought.

New research suggests that Mercury is shrinking between 10% and 30% faster than had been previously estimated. The team behind this research calculated that the planet has lost nearly 12 miles (19 kilometers) of its total diameter since it formed.

The researchers think that the extremity of this shrinking has gone unnoticed previously because bombardment from space rocks over time has created craters that obscured the evidence of this process.

Scientists say determining the extent of the shrinking of Mercury is key to investigating the composition of the planet's interior.

"More shrinking means Mercury could have a larger metal core, less light elements like silicon mixed into the metal core, or a higher starting temperature," team leader Gaku Nishiyama, of the German Aerospace Center (DLR) Institute of Space Research said in a statement.

Mercury's rocky past

Like all rocky planets in the solar system, Mercury was formed 4.5 billion years ago during a violent and turbulent time in the solar system's history, as rocks and asteroids collided with each other and were bound together.

These impacts generated heat, which Mercury has been losing ever since. As the interior of Mercury cooled, it also shrank. This caused geological wrinkles in the form of scarps and ridges to develop in the rocky outer layers of Mercury.

This cooling should result in Mercury shrinking in a roughly uniform way, and that would make these shortening structures common across the planet. However, asteroid impacts throughout its history have not only created craters that obscure signs of its geological history, but have also spread debris across the surface of Mercury. This makes wrinkles tougher to spot among the accumulation of billions of years' worth of geological features.

A rough grey surface with circular indentations

NASA's Messenger spacecraft spots an apparently fresh crater on Mercury during its early orbits on March 29, 2011. (Image credit: NASA/JHUAPL/CIW)

The team combined previous maps of Mercury's geology with new observations of the entire planet's surface roughness. They found the roughest terrain of Mercury featured the fewest wrinkles.

"It made us think that there's a process obscuring shortening structures," said Nishiyama, who thinks that impact debris in the roughest regions of Mercury is covering shrinking wrinkles.

The team then used the ridges and scarps in regions less affected by the dispersal of debris to estimate the amount of contraction. This indicated that missing features in rough areas could amount to 10% to 30% extra shrinkage over the 4.5 billion-year lifetime of Mercury. That amounts to a total change in diameter of up to 14.5 miles (23 kilometers) rather than the currently estimated 2.5 to 10 miles (4 to 16 kilometers).

"30% is a little bit surprising, but the corrected amount of contraction actually makes sense to me," Nishiyama said.

A grey sphere with a silver and gold spacecraft over it

An illustration of NASA's MESSENGER probe over the surface of Mercury (Image credit: NASA/JHU-APL)

There may be more surprises in store. Nishiyama believes that the updated figures could still be an underestimate. This estimate is based on data collected by NASA's MESSENGER probe, which ended in 2015. MESSENGER could only distinguish features larger than around 3 miles (5 kilometers) across.

In November 2026, the BepiColombo mission will start conducting scans of Mercury's surface in much higher resolution than this, and that could reveal even more shrinkage features.

The team's research was published on Thursday (Sept. 10) in the journal Geophysical Research Letters.

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Iconic Star Trek filming location spotted from space | Space photo of the day for Sept. 10, 2026

Captain Kirk and the Gorn face off in the corner of the screen pointing to the filming location on a satellite image below.

This new satellite image shows Vasquez Rocks in southern California, where Captain Kirk once faced off against the Gorn. (Image credit: NASA Earth Observatory/Michala Garrison/CBS via Getty Images)

Decades ago, Captain Kirk faced off against the Gorn on the uncharted desert planet Metron. But as we can see in new satellite imagery from NASA, that mysterious rocky world can actually be found right here on Earth in California.

What is it?

In this new image captured by the Operational Land Imager (OLI) on NASA's Landsat 9 satellite, you can see the wide variety of rock and vegetation in the area around Vasquez Rocks Natural Area County Park in southern California.

The 25-million-year-old Vasquez Rocks is a magnificent natural area with an incredible range of unique, large rocks jutting out of the ground. In this false-color image, you can see the area in shortwave-infrared and near-infrared wavelengths that show the differences in vegetation across the landscape.

And this location hides some amazing history. Not only is Vasquez Rocks home to incredible rock formations and desert vegetation, it is also where Captain Kirk fought the Gorn in Star Trek the Original Series. It's not a surprise the series chose this location for its infamous fight scene (among many other Trek scenes), as the massive, sun-bleached boulders pointing to the sky and barren landscape give it a distinctly alien feel.

A satellite view of Vasquez Rocks. A label shows where the Star Trek filming site is located.

A satellite view of the are around Vasquez Rocks. (Image credit: NASA Earth Observatory/Michala Garrison)

Why is it incredible?

While the rocky landscape of Vasquez Rocks is firmly fixed here on Earth, it has consistently made history as the backdrop to a whole host of iconic science fiction moments.

Indeed, Star Trek is one as Vasquez Rocks has been used for filming in a whole host of Trek episodes. It was even Spock's home world of Vulcan in the films Star Trek IV: The Voyage Home and Star Trek (2009).

But beyond Star Trek, the site has been used for filming sci-fi classics like Galaxy Quest, Battlestar Galactica and Planet of the Apes in addition to a whole host of cowboy movies and more.

It turns out that right here on Earth, we can find perfectly good alien worlds.

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Strange ‘fast radio bursts’ across the universe could help solve major cosmic mysteries: ‘It’s only the beginning’

Though their origins may be shrouded in mystery, fast radio bursts (FRBs) could be used to probe some of the universe's biggest puzzles. This includes probing the nature of dark matter, the invisible sort of matter that somehow dominates the universe, and dark energy, the mysterious force causing the expansion of our universe to accelerate. They could even shed light on the mysteries of neutrinos, or "ghost particles." Let's dive into how.

FRBs are brief but intense blasts of radio waves currently thought to erupt from rapidly rotating dead stars with the universe's strongest magnetic fields, called magnetars. As FRBs travel billions of light-years to reach Earth, they pass through dense clouds of gas and dust in galaxies. This "cosmic fog" changes the original FRB signal. What this means is these blasts of radio waves carry the fingerprints of how matter in the universe is distributed.

Mapping the distribution and "clumpiness" of ordinary matter in galaxies can then help trace the distribution of dark matter, the effect of dark energy and the mass of neutrinos.

"We've established that FRBs are a leading probe of the distribution of matter in the universe," team leader Kritti Sharma, a graduate student working with Vikram Ravi, a professor of astronomy at the California Institute of Technology (Caltech) and also part of the team, said in a statement. "These FRB data can be used to enhance cosmology experiments that are trying to answer questions about dark matter, dark energy, and the mass of neutrinos."

For this research, Ravi and Sharma analyzed a sample of about 100 FRBs. This represents the first time scientists have used FRBs to directly measure the impact of so-called "feedback" from galaxies on the clumpiness of matter in the large-scale regions between galaxies.

Cosmic ghosts and the dark universe

Ordinary matter, composed of atoms made up of electrons, protons and neutrons, accounts for just around 5% of the universe's energy/matter budget despite comprising stars, planets, moons, our bodies, next door's cat and everything we see around us on a day-to-day basis.

Of this budget, the other 95% is composed of dark energy (68%) and dark matter (27%). It's little wonder that scientists are very keen to better understand these two aspects of the cosmos, sometimes collectively referred to as the "dark universe."

Things get even more murky when considering how, of that 5%, the second most abundant particles in the universe, aside from particles of light or photons, are neutrinos. These get their nickname of "ghost particles" because they interact with other matter particles so infrequently that approximately 100 trillion neutrinos pass through your body every second without leaving any trace. This is possible because neutrinos are virtually massless, and scientists are keen to accurately measure the mass of these cosmic ghosts.

These three mysterious elements of the cosmos have played a vital role in the evolution of large-scale cosmic structures like galaxies and galaxy clusters. That means, in turn, that measuring the clustering of matter can reveal details about the aspects of the universe that influenced that clustering.

An orange and purple swirl with a black circle at its center. A bright tail emerges from the black circle

An illustration of a supermassive black hole pumping energy into its surroundings, a type of cosmic feedback that can smooth out clumpy cosmic matter. (Image credit: Robert Lea (created with Canva))

However, to do that, scientists also have to understand how other factors smooth out cosmic clumpiness. That includes the energy pumped out from the hearts of galaxies by feeding supermassive black holes, a type of cosmic feedback that smooths out clumpy cosmic matter lying outside galaxies.

"The feedback process thins the gas around the galaxies, redistributing matter across vast distances. It smooths out clumps of matter in a way that looks astonishingly similar to what massive neutrinos do, or what dark energy or dark matter theories predict," Ravi said. "Unless scientists can independently measure this contribution from feedback, they can't tell these effects apart."

That's where FRBs come in.

Flashes of light appear and disappear across a green oval with a grid pattern

An animation shows the random appearance of fast radio bursts (FRBs) across the sky. Astronomers have discovered about 85 since 2007. (Image credit: NRAO Outreach/T. Jarrett (IPAC/Caltech); B. Saxton, NRAO/AUI/NSF))

The researchers found that, while galactic feedback does indeed smooth surrounding material, making it less clumpy, the effect is weaker than has previously been measured.

"Our analysis of FRBs reveals how gas ejected by astrophysical feedback suppresses cosmic structure," team member Elisabeth Krause of the University of Arizona said in the statement. "This is amazing considering we only had about 100 FRBs in our sample. It's only the beginning."

The investigation of the universe with FRBs could get a major boost in 2029 when Caltech's Deep Synoptic Array (DSA) begins operating in Nevada. This powerful radio telescope is expected to find tens of thousands of FRBs, a major boon for cosmology.

The team's research was published on Tuesday (Sept. 8) in the journal Nature Astronomy.

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This ‘impossible’ black hole merger may be explained by a warp in spacetime

A "forbidden" merger between two massive black holes may not have been quite as impossible as previously thought. That's according to new research that suggests the black holes involved were smaller than expected.

On Nov. 23, 2023, the gravitational wave detector LIGO (Laser Interferometer Gravitational-Wave Observatory) detected tiny ripples in spacetime caused by the merger of two black holes. What was incredible about this signal, designated GW231123, was that it seemed to be the result of a black hole with 140 times the mass of the sun colliding with another that holds 100 solar masses.

This raised eyebrows among researchers because usual models of stellar evolution struggle to account for such massive black holes, especially ones that seemed to be spinning as fast as these two. While scientists have been attempting to explain how such an odd black hole binary could form. The team behind this new research suggests it doesn't need to be explained at all. They think that the masses of these black holes were an illusion.

The key to this illusion is a phenomenon called gravitational lensing, first predicted by Albert Einstein's 1915 theory of gravity, general relativity, which also first predicted the existence of gravitational waves. This theory says objects with mass cause the curvature of space and time, united as a four-dimensional entity called "spacetime." The more mass an object possesses, the greater the curvature, and because gravity arises from this curvature, the greater the gravitational influence.

Gravitational lensing occurs when light from a background object passes a massive foreground object. The foreground object can warp the fabric of spacetime in such a way that the light's path is curved. This means light from the same background source can reach Earth at different times, depending on how much that light was diverted.

This difference in travel time can magnify a background source, and it has been used to great effect to observe distant and ancient galaxies ordinarily too faint to be seen.

This research team thinks the effect also applies to gravitational waves, suggesting the signal GW231123 is an example of gravitationally lensed ripples in spacetime that made the black holes appear larger than they actually are.

"Like light, gravitational waves can also be deflected, magnified and split into multiple signals by massive objects," team member Miguel Zumalacárregui, group leader in the Astrophysical and Cosmological Relativity Department at the Albert Einstein Institute (AEI), said in a statement. "For gravitational waves, diffraction and interference effects give us an additional way to identify and study lensed signals."

Curved lines of different colors against a grid background

A diagram (not to scale) of how gravitational lensing works. (Image credit: NASA, ESA & L. Calçada)

To investigate this possibility, the team developed a mathematical model of gravitational lensing and created software powerful and fast enough to analyze it.

"If we assume that GW231123 was deflected and distorted by a compact object of about 190 to 850 solar masses — or by an extended structure such as a globular cluster — we can understand the observed high masses," said team member Srashti Goyal, who was based at the AEI when conducting the research. "Moreover, the lensing interpretation does not require unusually high spins."

When the team modeled the event with that consideration factored in, they found the merger involved a system with a mass of 140 solar masses, rather than the 240-solar-mass system initially theorized.

A purple hued image showing two black circles circling around one another in the center. There is a wave of pinkish gas trailing behind each of them.

A simulation of a black hole merger. (Image credit: NASA's Goddard Space Flight Center)

The team doesn't quite know what massive object is responsible for lensing the gravitational wave signal GW231123. But no matter what it is, if the team is correct, the lens could be something quite special.

"The nature of the lens remains a major mystery in our analysis, as individual compact lenses with 100 to 1,000 solar masses should be exceedingly rare," Zumalacárregui said. "Future work will need to establish whether such lenses can form, or whether an ensemble of lighter objects, including stars, can explain this event."

The team can't yet conclusively say if GW231123 is the first gravitationally lensed gravitational wave signal. Finding future signals of the sort will require upgrades to the sensitivity of detectors like LIGO.

Though even before that happens, the research does point to the utility of gravitational wave astronomy to study some of the universe's most violent events.

The team's research was published on August 25 in the Astrophysical Journal Letters.

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Astronomers discover two stars that joined together to form a binary system just 60 years ago

Using the ALMA (Atacama Large Millimeter/submillimeter Array) radio telescope, astronomers have watched as two stars come together to form a massive stellar binary. The observations revealed that these stars didn't form from the same collapsing cloud of gas and dust, as most binary stars are assumed to form, but instead came together later in their infancy.

Here on Earth, we are slightly prejudiced by our single sun to view stars as somewhat solitary bodies. However, around half of sun-sized stars in the Milky Way have a companion star. This percentage of stellar partnership rises to around 90% of massive stars. Eventually, these massive stars go supernova and shape their cosmic surroundings. Thus, understanding these binary systems is vital to our understanding of stars and of galaxies in general.

The team behind this research initially observed the still-growing massive stars, or protostars, in the binary system IRAS 07299−1651, located around 5,300 light-years away in 2019. At first, the researchers didn't see anything that suggested these stars didn't form from the same disk-shaped cloud of gas and dust that later fragmented. However, one thing really stood out: the disks of material surrounding and feeding these protostars are oddly misaligned.

Over the course of eight years, the team mapped subtle shifts in the position of the stars using ALMA in addition to the Very Large Array (VLA), as well as infrared images from the James Webb Space Telescope (JWST) and the Very Large Telescope (VLT).

"For the first time, we were able to watch two massive stars move around one another while they were still being born," team leader Yichen Zhang of Shanghai Jiao Tong University, China, said in a statement.

The team was able to reconstruct the full 3-dimensional structure of IRAS 07299−1651 for the first time, obtaining details about how the stars orbit each other, the way their disks are aligned, and the angle at which they blast jets into space.

"Each telescope revealed a different piece of the puzzle," team member Rubén Fedriani, of the Instituto de Astrofísica de Andalucía (IAA) in Granada, Spain, said. "The combination of radio and infrared observations provides the most exquisite detail on the formation of this massive protobinary system."

Unexpected chaos

The team's observations took them by surprise. They were expecting these stars to orbit each other in neat, near-circular orbits. Instead, the orbits were found to be highly flattened or "eccentric," almost parabolic.

If the stars had formed from the same disk of material, then even after it fragmented, the individual disks surrounding the stars would be aligned. However, that wasn't the case; the disks are tilted at a sharp angle to each other and to the orbits of the stars.

"It felt like solving a three-dimensional puzzle," team member Yao Wang of Shanghai Jiao Tong University said. "Each new observation added another piece, and eventually the orbit, disks, and jets all came together into a single, coherent picture."

two orange disks with blue jets streaming from their centers

An artist’s impression of the formation of a close massive binary system, showing misaligned disks around two young stars. (Image credit: Y. Zhang)

The chaotic structure of IRAS 07299−1651, as observed by the team, is difficult to explain if the two stars emerged from the same disk of material.

Instead, the researchers theorize that the two stars were born in individual clouds of gas and dust, before a chance encounter brought the two infant stars and their respective natal cocoons together.

Tracing back the orbits of the stars, the researchers found that this encounter likely occurred around 60 years ago. Considering stars live for billions of years, that is an instant on a cosmic timescale. The disk-shaped pockets of material around the stars have thus far survived the encounter, retaining their well-defined structures.

"This study demonstrates that the early lives of stars can be quite chaotic, with a chance encounter leading to this gravitational dance and stellar coupling," team member Jonathan C. Tan of the University of Technology and the University of Virginia said.

A large yellow sphere next to a smaller red sphere

A binary star system, is IRAS 07299−1651 destined to settle to form such a system? (Image credit: NASA)

What the team can't yet establish is whether these stars are destined to stick together or if they will eventually move apart. Indeed, this fate may not have been sealed yet; interactions with the surrounding gas could determine what shape this system takes in the future.

The team hopes that further observations of IRAS 07299−1651 will help to better understand what the future holds for these stars.

In the meantime, the long-term monitoring approach adopted by the researchers could provide scientists with a powerful new way of investigating other young massive binary systems. This could reveal how common encounters like this are and if more binary systems are composed of stars brought together by chance encounters.

The team's research was published on Tuesday (Sept. 8) in the journal Nature Astronomy.

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NASA’s newly launched Roman Space Telescope will ‘directly’ image exoplanets. But what does that mean?

A brand new observatory began its tenure on Aug. 30 — it's called the Nancy Grace Roman Space Telescope, and it's equipped with a high-tech tool that can directly photograph planets beyond our solar system.

The tool is called a coronagraph; in simple terms, a coronagraph is a device that can be affixed to a telescope and block out the light of a star the telescope is looking at to study features around that star. Without such a device, starlight can be so overpowering that it outshines details nearby. You can think of a coronagraph as a way to recreate a total solar eclipse, except instead of the moon blocking out the sun it's a humanmade mask of sorts that does that trick.

But while coronagraphs have been used many times before, the one that just launched toward the stars is unprecedented. "The Roman Space Telescope is carrying the most advanced coronagraph that humanity has ever put into space," Dominic Benford, the telescope's program scientist, told Space.com.

If you can remember the striking "Pale Blue Dot" image of Earth that NASA's Voyager 1 spacecraft captured while floating about 3.7 billion miles (6 billion kilometers) from the sun, this is the kind of thing scientists expect to see with Roman's coronagraph. A menagerie of Pale Brown Dots should soon make us feel the weight of our existence.

"I love the feeling of smallness that comes from understanding you're not alone in the universe," Vanessa Bailey, Roman's coronagraph instrument scientist, told Space.com.

A hazy blueish image has one beam of light in the center-right. There's a tiny blue dot in the beam.

Earth as a "pale blue dot" seen by Voyager 1 in 1990. (Image credit: NASA/JPL-Caltech)

How does it work?

Coronagraphs aren't really a new thing. Often, they're even used to study our own sun.

For example, NASA's PUNCH mission — which stands for Polarimeter to Unify the Corona and Heliosphere — launched in 2025 and consists of four spacecraft, one of which holds a coronagraph. This coronagraph blocks out the light of our sun in order to reveal the wispy tendrils of the sun's outer atmosphere, or corona.

"In fact, more than 100 years ago, astronomers used coronagraphs to create an artificial eclipse to study the sun's corona," Bailey said during a press briefing on Aug. 29, a day before Roman launched to space. "That's the reason for the name."

But when it comes to other stars, coronagraphs hold another purpose. They can block out a star's light in such a way that planets actually orbiting that star come into view.

"We can block that starlight until we have only a few parts per billion of the light of the star remaining," Benford said of Roman's coronagraph. As a result, he explained, "we can directly see the light bouncing off something like a Jupiter around another star, which we've never been able to do before."

A red screen showing a circle in the center and a blast of light comes out the top left.

NASA's Solar and Heliospheric Observatory, or SOHO, constantly observes the outer regions of the sun's corona using a coronagraph, which blocks the bright solar disk. (Image credit: ESA/NASA/SOHO)

This process will surely give us our Pale Brown Dots — but to take things a step further, scientists will also be able to dissect the light bouncing off the theoretical Jupiter to reveal what the atmosphere of the world is like, too.

To be clear, Roman isn't the only astronomy tool we have that utilizes a coronagraph while looking beyond our solar system. Even the James Webb Space Telescope and Hubble Space Telescope have their own, for that matter. However, Roman's is far more complex.

For one, the Roman's coronagraph doesn't exactly "block" out starlight like a standard coronagraph does. For the "moon" in its artificial eclipses, it uses a combination of patterned disks and special filters to create destructive interference with the light of a target star. Destructive interference means competing waves of light cancel one another out, leading to a zeroed amplitude. In effect, this blocks out the starlight as necessary and only allows light reflected off the planets of interest to pull through and reflect off the coronagraph's mirrors.

A diagram showing a disk being put into a device. There is a boxout at the top right showing a circular pattern.

A diagram showing what the disk's pattern might look like. (Image credit: NASA's Goddard Space Flight Center)

The first active coronagraph

Which brings us to the next special part about Roman's coronagraph: It's the first "active" coronagraph to fly in space.

What this means is it can adjust those mirrors in real-time to make sure its exoplanet observations are as clear as possible. This is important because as light reflects off the coronagraph's mirrors, it can create small distortions that mess up the delicate destructive interference dance. You'd need to adjust to bring the balance back, and these adjustments are possible because Roman's coronagraph has hundreds of tiny pistons built into its mirrors. This makes them deformable so they can change shape to account for distortions.

If it all works out, this coronagraph should be capable of detecting exoplanets that are about 100 million times fainter than their stars.

"These deformable mirrors are a real engineering feat," Bailey said during the press briefing. "They can be commanded with the precision approaching the size of an atom, and this is what really allows us to make this transformative performance."

A bunch of golden components and wires in top of a large black box. A person in a white clean room suit stands behind the contraption.

The Roman Space Telescope's coronagraph as scientists were working on it. (Image credit: NASA/JPL-Caltech)

As for what the specific hope is for Roman's coronagraph, Bailey explained there are a few nearby star systems the team is particularly interested in peering into because we have hints of Jupiter-like planets orbiting in those systems that still haven't been imaged. "Or," she said, "there may be really interesting remnants of dust and debris from the process of planet formation." Perhaps that dust could exist in the habitable zones of the stars Roman looks toward, and perhaps this could tell us more about the birth of planet Earth.

"That is interesting in its own regard but also interesting as a precursor to the Habitable Worlds Observatory," Bailey said, in reference to NASA's next great project that will be equipped with a more advanced version of Roman's coronagraph. "We can study how dusty these nearby systems are and understand whether any of them might have too much dust for us to be able to observe an Earth-like planet in the future."

a space telescope unfurls a foiled cover on its top

An animation shows what Roman looks like deploying in space. (Image credit: NASA’s Goddard Space Flight Center Conceptual Image Lab)

While Roman will pretty much be focusing on Jupiter-like worlds because they're big enough to be detected with its current capabilities, HWO could certainly find another Earth someday.

From 6,000 exoplanets to 100,000

And before we wrap up, we must briefly mention this newly christened exoplanet hunter's partner tool, the majorly impressive Wide Field Instrument (WFI) that can survey huge swaths of sky in one go. It is because of the partnership between the WFI and its coronagraph that Roman will immensely expand our exoplanet gallery, says associate administrator for NASA's Science Mission Directorate Nicky Fox. The coronagraph won't be finding new exoplanets alone, but rather will be diving deeper into exoplanets the WFI finds first.

Blue reflective squares are attached to an instrument that hangs from above. A person in a white clean room suit is putting a metal door on top of the reflective squares.

The Roman Space Telescope's WFI. (Image credit: NASA/Chris Gunn)

WFI will use two different techniques to contribute to our gallery. The first one is called the transit technique, and it's the same method big names like Kepler and TESS tapped into. It involves noticing dips in starlight that happen when a possible planet transits the face of a star from the telescope's vantage point. "If you see that happen multiple times," Fox said, "you can infer that it's a planet, and you can get the radius and the size of the planet from that observation."

The second technique has to do with gravitational lensing, which refers to how objects with mass in space (and therefore gravitational influence) can warp the very fabric of spacetime and alter the path of light traveling through the affected region. What comes to mind might be a mighty galaxy cluster twisting spacetime like a sheet of satin, but little things like stars and planets can do it, too. The so-called "microlensing" effect of smaller objects warping spacetime leads to the brightening of background objects.

Fox sums up WFI's two techniques in a nutshell: "If you see a little dip, that can suggest there's a transiting planet. You see a little brightening, that can suggest there's a microlensing planet."

For WFI, the microlensing technique will be sensitive to Earth-size planets in the habitable zones of their stars, while the transiting technique will be more sensitive to planets closer to their stars. And as Bailey reminds us, there are absolute heaps of planets to test Roman out on: "When you look up at the night sky, most of those stars have planets."

Right now, we only know of about 6,000 of those worlds. Fox believes this new space telescope could unveil 100,000 more.

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Indonesian volcanic eruption spotted from space | Space photo of the day for Sept. 9, 2026

The Anak Krakatau volcano began erupting on Sept. 4, 2026, as seen here on Sept. 5 by the Landsat 8 satellite jointly operated between NASA and the U.S. Geological Survey (USGS) (Image credit: NASA Earth Observatory/Michala Garrison)

A volcano on an Indonesian archipelago began erupting on Sept. 4, and satellites in orbit have been watching closely.

What is it?

The volcano Anak Krakatau started spitting out ash and lava on Sept. 4. On an archipelago between Sumatra and Java, the island volcano's sudden eruption grounded flights, closed schools and even stopped fishing in the area.

The volcano launched ash into the air and into the city of Jakarta and the Lampung province during a 25-hour-long eruption. But even following this eruption, Anak Krakatau remained active throughout the weekend. In fact, the volcano is still so active that it could erupt again soon.

But it wasn't just people on Earth watching the volcano erupt this past weekend. The Landsat 8 satellite, operated by NASA and the U.S. Geological Survey (USGS), spotted a white plume of volcanic gas billowing into the atmosphere all the way from space. The white plumes of gas are thought to mainly contain water vapor, carbon dioxide and sulfur dioxide, while ash and debris make up the brown clouds surrounding the plumes.

Why is it incredible?

While Anak Krakatau simmers after this most recent eruption, this event isn't a major shock, as the volcano sits in what is known as the "Ring of Fire." This "ring" (a loose term, as it's not exactly a ring) snakes about 25,000 miles (40,000 kilometers) around the Pacific Ocean and includes over 750 volcanoes, some dormant and some active.

In fact, in Indonesia alone there are 500 volcanoes, and 127 of them are active, including Anak Krakatau. And this volcano has a particularly interesting story: It emerged from the sea in 1927, rising from the caldera formed by the 1883 eruption of Krakatau (also known as Krakotoa), which was one of the most famous and destructive volcanic events in history. (Anak Krakatau means "child of Krakatau" in the Indonesian language.)

While not all geologists agree on the exact margins of the Ring of Fire, it rests on a string of tectonic plates and has existed for over 35 million years. And not only is this ring home to hundreds of volcanoes, it's also a hot spot for earthquakes.

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China on track to launch Mars sample-return mission in 2028: ‘If accurate, this represents a Sputnik moment’

China is making progress on its Tianwen 3 Mars sample return mission, which aims to bring back to Earth roughly 500 grams (17.6 ounces) of Red Planet collectibles in 2031.

According to the China National Space Administration, the Tianwen 3 mission will have a lander, an ascender, a service capsule, an orbiter and an Earth reentry module.

If all goes to plan, Tianwen 3 will launch in 2028 on two Long March 5 heavy-lift rockets from the Wenchang Space Launch Site on the island of Hainan, China's southernmost province.

Sputnik moment

"The Tianwen 3 mission is progressing smoothly, with intensified efforts being made to overcome technical challenges," Hou Zengqian, the mission's chief scientist, recently told CCTV, a state-run Chinese broadcaster.

"The probe equipment has entered the prototype development phase, and scientifically, many scientist teams from across the country are working together to tackle the challenges in accordance with the mission's scientific objectives," Hou added.

Meanwhile, NASA's plans for hauling Mars samples to Earth are murky at the moment. So China appears to be in the lead to notch a major space milestone.

"If accurate, this represents a Sputnik moment," said former NASA "Mars Czar" Scott Hubbard, referring to the reported Tianwen 3 progress.

"China will not only grab the headlines but may be the first to find evidence of life on another planet," Hubbard, who also previously directed NASA's Ames Research Center in Silicon Valley, told Space.com.

diagram showing a spacecraft's route to from earth to mars and back again

Diagram of China's Tianwen 3 Mars sample return mission. (Image credit: The University of Hong Kong/Zengqian Hou, et al.)

Top scientific priority

"The Tianwen 3 mission will look for microbial traces potentially similar to early forms of life on Earth, while also taking into consideration the possibility of unknown forms of life that may have emerged through Mars' unique evolutionary history, providing crucial evidence to answer this major scientific question," Hou told the state-run Xinhua news agency in a recent interview.

Searching for potential signs of life on Mars is the top scientific goal of the Tianwen 3 mission, Hou said on Sept. 3 during the 2026 International Deep Space Exploration Conference on, which was held in Hefei, the capital of eastern China's Anhui Province.

Landing site

China's Mars sample-return trek will be launched "around 2028" on two Long March 5 rockets departing from the Wenchang Space Launch Site in China's southernmost island province of Hainan. (Launch windows for Mars missions come around just once every 26 months. The next one opens in November-December of this year, and the one after that, which Tianwen 3 apparently is targeting, runs from December 2028 to January 2029.)

Hou also said China expects to finalize the landing site for the mission by the end of 2026, with Chinese specialists advancing work on a next-generation geological map of Mars in its entirety.

If everything goes according to plan, the mission will collect samples from the Martian surface and then send them back to Earth around 2031.

"Regardless of whether signs of life are found, the returned Martian samples will have irreplaceable scientific value," Hou said.

Tackle the challenges

Hou added that analyses of the returned samples at microscopic, molecular and isotopic scales could deepen our understanding of Mars' geology and environment, as well as the evolution of habitability and the conditions under which life may originate.

According to Hou, Mars sample return is an extremely complex project, with landing-site selection, planetary protection and contamination control, and the identification of potential signs of life among its key challenges.

Chinese Mars researchers are selecting candidate landing sites for the mission based on factors that include geological age, history of water activity, habitability and the potential for preserving biosignatures.

Planetary protection lab

Xinhua reported last month that a "planetary protection laboratory" is to be built in the first phase of Hefei's Deep-Space Science City in east China's Anhui Province, citing the Deep Space Exploration Laboratory (DSEL).

"The planetary protection laboratory will implement a two-way protection system that guards both the returning Martian samples and Earth's biosphere," Xinhua reports.

The lab's tasks encompass sample sterilization, unsealing, processing and biological risk assessment. "The facility is designed to support the implementation of major deep-space missions and to enable scientific research on Martian samples," added Xinhua.

China "will follow the planetary protection policies of the Committee on Space Research, to prevent biological contamination of Mars by terrestrial organisms and to protect Earth from any potential extraterrestrial life forms that may be carried back in the samples," said Li Hang, director of the development planning department at DSEL, according to Xinhua.

You can view a video about China's Mars sample return plans here.

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Did Venus eat its own moon?

Scientists may finally know why Venus, Earth's twin, lacks a moon, finding that the hottest planet in the solar system may have consumed its own natural satellite.

Venus is often referred to as Earth's twin due to its size, mass, rocky composition, and distance from the sun, but there are some glaring differences between the two planets. Aside from Venus' blisteringly hot temperature, which could melt lead, incredible surface pressure, violent high-speed winds, and clouds of sulfuric acid, one of the key differences between Earth and Venus can be seen from afar. While our planet has a constant companion in the form of the moon, Venus lacks a moon of its own. In fact, the only solar system planets lacking moons are Venus, the second planet from the sun, and Mercury, the closest planet to the sun.

One question that scientists have puzzled over for years is whether Venus always lacked a moon, or if the hottest planet in the solar system once had a natural satellite and somehow lost it. Now, a team of researchers may have arrived at an answer, determining the fate that would have befallen a hypothetical moon orbiting Venus.

"I have always had a fascination with moon formation and evolution in the solar system, and particularly with Venus since my research is centered around its evolution and potential for past habitability," team leader Stephen R. Kane of the University of California, Riverside told Space.com. "Venus is Earth's twin, and both are nearly identical in size, mass, and composition. However, Earth has a large moon, and Venus has no moon at all, not even a small captured satellite.

"Venus undoubtedly experienced large impacts, just as Earth has, and so has had as much, if not more, opportunity to form a moon similar to what we see in our own skies."

Kane and colleagues constructed a simulation to test their ideas of what could have become of the Venusian moon.

"The work involved going back to fundamental physics and creating the simulation from the ground up, which I validated by ensuring I could reproduce the evolution of the Earth-moon system," Kane said. "The moment I realized that our model provided a complete explanation for Venus not having a moon was an exciting one!"

Did Venus consume its own moon?

The team modelled a gravitational tug-of-war between Venus, a hypothetical moon, and the sun, following this forward over billions of years.

"This is the same physics that governs our own moon, which is slowly drifting away from Earth. We ran the calculations across a wide range of possibilities for how fast Venus was spinning and how massive its moon might have been, using two independent mathematical descriptions of how tides work," Kane explained.

The researcher said that this was done so the conclusions reached wouldn't hinge on one set of assumptions. They found in most cases a Venusian moon would not drift safely outward the way ours does. Instead, the modelling showed that a moon orbiting Venus would eventually reverse its course and spiral inward, causing it to be torn apart by the planet's gravity.

Kane and colleagues found that possessing an intimidating size wouldn't guarantee a Venusian moon's survival, either.

"An interesting aspect is that a heavier moon is destroyed faster, since a massive moon would drain Venus's spin so efficiently that it hastens its destruction," Kane added.

A striped brown sphere against a black background

Venus as seen from Earth may look peaceful, but up close, it is a hellish world that may have destroyed its own moon. (Image credit: Starry Night)

But are there any circumstances under which a Venusian moon could have survived?

"Survival came down to two main things: Venus had to be spinning fast when the moon formed, with a day shorter than about 12 hours, and the moon couldn't be too massive, up to roughly the mass of our own moon," team leader Stephen R. Kane of the University of California, Riverside told Space.com. "In that narrow window, the moon migrates outward and stabilizes, much as Earth's did. Outside that range, the moon is unfortunately doomed to be consumed by Venus.

"So a surviving moon would have had to be modest in size, orbiting a rapidly spinning early Venus, which are conditions that don't match what we think early Venus was actually like."

We may never conclusively know if Venus has indeed destroyed its own moon, as Kane thinks that collecting direct evidence from astronomical observations will be very difficult.

"Finding direct observational evidence is pretty tough. A moon lost billions of years ago would leave little to no direct trace we can point a telescope at today, so we can't observe the event itself," Kane said. "However, there are indirect avenues. For example, if a moon was destroyed and its debris rained down on Venus, it could have left a chemical fingerprint in the planet's surface or atmosphere, and upcoming missions to Venus, including NASA's DAVINCI (Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging) probe, will measure atmospheric composition in detail."

If missions such as DAVINCI could help us develop a better understanding of the Venusian interior, then this would also improve the models such as the one used in this research. That is because the outcomes of such models depend on properties of Venus's interior, which aren't currently well understood.

"There's a broader test beyond our solar system because our results predict that slowly rotating, Venus-like planets around other stars should generically lack large moons, so as astronomers begin searching for moons around exoplanets, that's a prediction that can eventually be checked against real data," Kane said.

A spherical silver spacecraft against a fiery orange background

An artist's depiction of the DAVINCI probe nearing the surface of Venus. (Image credit: NASA's Goddard Space Flight Center)

Kane and colleagues don't intend to rest on their laurels while further data from Venus or even Venus-like exoplanets are delivered. They have plenty to work on in the meantime.

"There are numerous implications of our work that I would like to explore further. These include the compositional and atmospheric effects of a Venusian moon consumption event that may be testable now," Kane concluded. I would also like to explore similar effects for Mercury and Mars, and conduct further studies on exoplanet cases where such moon collision scenarios may have occurred."

The team's research is available as a pre-peer-reviewed paper on the repository site arXiv.