Wednesday, 18 March 2026

NASA’s Hubble Unexpectedly Catches Comet Breaking Up

5 Min Read

NASA’s Hubble Unexpectedly Catches Comet Breaking Up

A time sequence of three panels side by side. From left to right, the panels are labeled November 8, 2025; November 9, 2025; and November 10, 2025. This series of images from NASA’s Hubble Space Telescope of the fragmenting comet C/2025 K1 (ATLAS), or K1 for short, was taken over the course of three consecutive days. The sequence shows the progressive disintegration of the comet over this brief period. Each panel features several bright, fuzzy, blue, streaking lights in a diagonal line from the upper left to the lower right of a black background. In the first panel, four comet-like objects appear. The largest is the second from the upper left. In the second panel, the largest object has broken into two pieces. In the third panel, the pieces appear to be moving away from each other along the invisible diagonal line.

A series of images from NASA’s Hubble Space Telescope of the fragmenting comet C/2025 K1 (ATLAS).

Credits:
Image: NASA, ESA, Dennis Bodewits (AU); Image Processing: Joseph DePasquale (STScI)

In a happy twist of fate, NASA’s Hubble Space Telescope just witnessed a comet in the act of breaking apart. The chance of that happening while Hubble watched is extraordinarily minuscule. The findings published Wednesday in the journal Icarus.

The comet K1, whose full name is C/2025 K1 (ATLAS)—not to be confused with interstellar comet 3I/ATLAS—was not the original target of the Hubble study.

“Sometimes the best science happens by accident,” said co-investigator John Noonan, a research professor in the Department of Physics at Auburn University in Alabama. “This comet got observed because our original comet was not viewable due to some new technical constraints after we won our proposal. We had to find a new target—and right when we observed it, it happened to break apart, which is the slimmest of slim chances.”

This series of images from NASA’s Hubble Space Telescope of the fragmenting comet C/2025 K1 (ATLAS) was taken over the course of three consecutive days: Nov. 8, 9, and 10, 2025. This is the first time Hubble has witnessed a comet so early in the process of breaking up.

Image: NASA, ESA, Dennis Bodewits (AU); Image Processing: Joseph DePasquale (STScI)

Noonan didn’t know K1 was fragmenting until he viewed the images the day after Hubble took them. “While I was taking an initial look at the data, I saw that there were four comets in those images when we only proposed to look at one,” said Noonan. “So we knew this was something really, really special.”

This is an experiment the researchers always wanted to do with Hubble. They had proposed many Hubble observations to catch a comet breaking up. Unfortunately, these are very difficult to schedule, and they were never successful.

“The irony is now we’re just studying a regular comet and it crumbles in front of our eyes,” said principal investigator Dennis Bodewits, also a professor in Auburn University’s Department of Physics.

“Comets are leftovers of the era of solar system formation, so they’re made of ‘old stuff’—the primordial materials that made our solar system,” said Bodewits. “But they are not pristine—they’ve been heated; they’ve been irradiated by the Sun and by cosmic rays. So, when looking at a comet’s composition, the question we always have is, ‘Is this a primitive property or is this due to evolution?’ By cracking open a comet, you can see the ancient material that has not been processed.”

Hubble caught K1 fragmenting into at least four pieces, each with a distinct coma, the fuzzy envelope of gas and dust that surrounds a comet’s icy nucleus. Hubble cleanly resolved the fragments, but to ground-based telescopes, at the time they only appeared as barely distinguishable, bright blobs.

Hubble’s images were taken just a month after K1’s closest approach to the Sun, called perihelion. The comet’s perihelion was inside Mercury’s orbit, about one-third the distance of the Earth from the Sun. During perihelion, a comet experiences its most intense heating and maximum stress. Just past perihelion is when some long-period comets like K1 tend to fall apart.

Diagram shows K1’s path. With Sun at center, nearly circular orbits of Mercury, Venus, Earth, and Mars appear against black background. In sharp contrast is K1’s tight parabolic curve, marked by solid, light blue curving line illustrating how K1 swooped toward the Sun from above. It curved around the Sun, coming closest inside Mercury’s orbit, and continued its outbound journey. After passing the Sun, as K1 approached Mercury’s orbit, NASA’s Hubble Space Telescope captured the inset image of comet. Five, bright, fuzzy, blue, comet-like objects streak diagonally from upper left to lower right of a black box outlined in white. At outside top of box is label C/2025 K1 (ATLAS). Outside the right side of box is a white, horizontal line labeled November 10, 2025. To right of this line is a perpendicular, vertical line pointing to a white glow just inside Mercury’s orbit that illustrates K1. To left of this glow, the comet’s outbound path is marked by a dashed gray line that continues off the image.

This diagram shows the path Comet C/2025 K1 (ATLAS), or K1, took as it swung past the Sun and began its journey out of the solar system. NASA’s Hubble Space Telescope captured the inset image of the fragmenting comet just a month after K1’s closest approach to the Sun.

Illustration: NASA, ESA, Ralf Crawford (STScI)

Before it fragmented, K1 was likely a bit larger than an average comet, probably around 5 miles across. The team estimates the comet began to disintegrate eight days before Hubble viewed it. Hubble took three 20-second images, one on each day from Nov. 8 through Nov. 10, 2025. As it watched the comet, one of K1’s smaller pieces also broke up.

Because Hubble’s sharp vision can distinguish extremely fine details, the team could trace the history of the fragments back to when they were one piece. That allowed them to reconstruct the timeline. But in doing so, they uncovered a mystery: Why was there a delay between when the comet broke up and when bright outbursts were seen from the ground? When the comet fragmented and exposed fresh ice, why didn’t it brighten almost instantaneously?

The team has some theories. Most of a comet’s brightness is sunlight reflected off of dust grains. But when a comet cracks open, it reveals pure ice. Maybe a layer of dry dust needs to form over the pure ice and then blow off. Or maybe heat needs to get below the surface, build up pressure, and then eject an expanding shell of dust.

“Never before has Hubble caught a fragmenting comet this close to when it actually fell apart. Most of the time, it’s a few weeks to a month later. And in this case, we were able to see it just days after,” said Noonan. “This is telling us something very important about the physics of what’s happening at the comet’s surface. We may be seeing the timescale it takes to form a substantial dust layer that can then be ejected by the gas.”

NASA’s Goddard Space Flight Center; Lead Producer: Paul Morris

The research team is looking forward to finishing the analysis of the gases to come from the comet. Already, ground-based analysis shows that K1 is chemically very strange—it is significantly depleted in carbon, compared with other comets. Spectroscopic analysis from Hubble’s STIS (Space Telescope Imaging Spectrograph) and COS (Cosmic Origins Spectrograph) instruments is likely to reveal much more about the composition of K1 and the very origins of our solar system, as NASA’s space telescopes continue to contribute to our understanding of planetary science.

The comet K1 is now a collection of fragments about 250 million miles from Earth. Located in the constellation Pisces, it is heading out of the solar system, not likely to ever return.

The Hubble Space Telescope has been operating for over three decades and continues to make ground-breaking discoveries that shape our fundamental understanding of the universe. Hubble is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope and mission operations. Lockheed Martin Space, based in Denver, also supports mission operations at Goddard. The Space Telescope Science Institute in Baltimore, which is operated by the Association of Universities for Research in Astronomy, conducts Hubble science operations for NASA.

Related Images & Videos

Fragmentation of Comet C/2025 K1

Diagram shows K1u2019s path. With Sun near middle right of image, truncated nearly circular orbits of Mercury, Venus, Earth, and Mars appear against black background. K1u2019s tight parabolic curve, marked by solid, light blue curving line, illustrates how K1 swooped toward the Sun from above. It curved around the Sun, coming closest inside Mercuryu2019s orbit, and continued its outbound journey.nAfter passing the Sun, as K1 approached Venusu2019 orbit, NASAu2019s Hubble Space Telescope captured the inset image of comet. Five, bright, fuzzy, blue, comet-like objects streak diagonally from upper left to lower right of a black box outlined in white. At outside top of box is label C/2025 K1 (ATLAS). Outside the right side of box is a white, horizontal line labeled November 10, 2025. To right of this line is a perpendicular, vertical line pointing to a white glow just inside Mercuryu2019s orbit that illustrates K1. To left of this glow, the cometu2019s outbound path is marked by a dashed gray line that continues off the image.

Comet C/2025 K1 Orbit Illustration

Three annotated panels side by side show K1 fragmenting over three consecutive days. Arrows show the orientation of object on sky.u00a0At top left of first panel, label on first line reads Fragmentation of Comet C/2025 K1 (ATLAS). Second line reads HST STIS MIRVIS. From left to right, panels are labeled November 8, 2025; November 9, 2025; and November 10, 2025.nnEach panel shows several bright, fuzzy, blue objects streaking diagonally from upper left to lower right of black background. In first panel, four comet-like objects are numbered 1 thru 4. In second panel, the largest object has broken into two pieces, 2a and 2b. In third panel, pieces appear to be moving away from each other diagonally.nnu00a0nnArrows on last panel show orientation of image on sky. Arrow labeled N points to 8:30. Arrow labeled E points to 5:30. Relationship between north and east on the sky as seen from below is flipped relative to direction arrows on a map of the ground as seen from above.

Comet C/2025 K1 Compass Image

This annotated series of images from NASA’s Hubble Space Telescope of the fragmenting comet C/2025 K1 (ATLAS), or K1 for short, was taken over the course of three consecutive days: Nov. 8, 9, and 10, 2025. Arrows show the orientation of the image on the sky.

Fragmenting Comet C/2025 K1

This animation steps through the three images from NASA’s Hubble Space Telescope of the fragmenting comet C/2025 K1 (ATLAS), or K1 for short, taken consecutively on Nov. 8, 9, and 10, 2025. Captured by Hubble’s STIS (Space Telescope Imaging Spectrograph) instrument, t…

Video: Hubble Accidentally Catches Comet Breaking Up

In a happy twist of fate, NASA’s Hubble Space Telescope just witnessed a comet in the act of breaking apart. The chance of that happening while Hubble watched is extraordinarily miniscule.

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Last Updated

Mar 18, 2026

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Andrea Gianopoulos

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Ann Jenkins, Christine Pulliam
Space Telescope Science Institute
Baltimore, Maryland

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Wave of Dust Rolls Through Texas

A line of tan suspended dust stretches roughly northwest-to-southeast for over 100 miles across West Texas.

March 15, 2026

The Ides of March brought perilous weather to West Texas and the state’s Panhandle. A strong cold front blasted south across the arid plains on March 15, 2026, bringing stiff winds that stirred up a curtain of dust. The cloud of suspended particles slashed visibility and made for treacherous travel as it swept across the region. The high winds, coupled with dry conditions, also raised the risk of wildland fires.

The MODIS (Moderate Resolution Imaging Spectroradiometer) on NASA’s Aqua satellite captured this image of blowing dust on its march across Texas at about 4:45 p.m. Central Time (21:45 Universal Time) on March 15. An image acquired by the Terra satellite about 5 hours earlier shows the wall of dust when it was approximately 150 miles (240 kilometers) to the northeast.

Footage captured by a storm chaser shows visibility plummeting to nearly zero as the dense plume passed; similar conditions contributed to a multivehicle crash in North Texas. The National Weather Service also issued a Red Flag Warning for March 15 due to the combination of high winds, low relative humidity, and dry fuels. Several wildland fires ignited in the Panhandle, prompting evacuations, according to news reports.

Weather conditions took a sharp turn with the cold front’s passage. A weather station in Pecos recorded a high of 88 degrees Fahrenheit (31 degrees Celsius) at 4:30 p.m. local time on March 15, around the time of this image. Temperatures then dropped abruptly, hitting a low of 39ºF (4ºC) around 6 a.m. the next morning. Pecos saw sustained winds of about 25 miles (40 kilometers) per hour with gusts up to 40 miles (64 kilometers) per hour on March 15. Several stations in the Panhandle clocked gusts over 60 miles (97 kilometers) per hour.

Much of northern and western Texas has been experiencing moderate or severe drought, according to the U.S. Drought Monitor. Though dust storms are typical in the region this time of year, the lack of rain parches vegetation, dries the land, and increases the area’s susceptibility to these events.

NASA Earth Observatory image by Michala Garrison, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview. Story by Lindsey Doermann.

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March 15, 2026

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References & Resources

Amarillo Globe-News (2026, March 16) Video of wildfires, dust storms forcing evacuations in Texas Panhandle. Accessed March 17, 2026.
NASA Earth Observatory (2025, March 6) Storm Brings a Potpourri of Hazards to the U.S. Accessed March 17, 2026.
NASA Earthdata (2026) Dust/Ash/Smoke. Accessed March 17, 2026.
National Weather Service, Dust Storms and Haboobs. Accessed March 17, 2026.
National Weather Service, via Iowa Environmental Mesonet (2026, March 14) Urgent – Weather Message. Accessed March 17, 2026.
Texas Storm Chasers (2026, March 13) Texas Weather Roundup: Dangerous Fire Weather, Damaging Winds & Sharp Cold Front Sunday. Accessed March 17, 2026.

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NASA’s X-59 Prepares for Second Flight

4 min read

Preparations for Next Moonwalk Simulations Underway (and Underwater)

An aircraft resting on a section of runway as seen from the front, with its nose facing the camera. The early morning sky is orange in the background.

As its team prepared for second flight, NASA’s X-59 quiet supersonic aircraft underwent engine run testing on Thursday, March 12, at NASA’s Armstrong Flight Research Center in Edwards, California.

NASA/Jim Ross

NASA’s X-59 experimental aircraft is preparing for its second flight, a step that will set the pace for more flight testing in 2026.

Over the coming months, NASA will take the quiet supersonic jet faster and higher, while validating safety and performance, a process known as envelope expansion.

NASA test pilot Jim “Clue” Less will be at the X-59’s controls for second flight. Less will take off and land at Edwards Air Force Base, near the X-59’s home at NASA’s Armstrong Flight Research Center in Edwards, California.

“This will be the first time I’ve flown an X-plane,” Less said. “I think I’ll mostly be focused on getting the test cards done and getting them done correctly. It’ll probably sink in later that I was in the X-59.”

Less will be accompanied by NASA test pilot Nils Larson, who will be flying nearby in a NASA F/A-18 aircraft to observe the X-59.

The X-59 made its first flight Oct. 28, 2025, with Larson as pilot. Afterward, NASA and contractor Lockheed Martin completed an extensive round of post-flight maintenance and inspections. The work involved removing the engine, a section of the tail known as the lower empennage, the seat, and more than 70 panels to perform inspections. All have been reinstalled.

“These guys know what they’re doing. We couldn’t do something like this without a really competent team of hardworking folks,” Less said. “Nils trusted them for the first flight. I trust them for the second flight and every flight after that.”

NASA test pilot Jim “Clue” Less sits in the X-59's cockpit in a close-up photo. Less is wearing his flight suit, a flight helmet, and glasses, with a radio pressed close to his face. His name and call sign are written just under the canopy glass.

NASA test pilot Jim “Clue” Less took the X-59 through its engine run test on Thursday, March 12, at NASA’s Armstrong Flight Research Center in Edwards, California. Less will pilot the aircraft for its second flight.

NASA/Jim Ross

The team completed one of the last ground tests before the flight on March 12 – an engine run firing up the X-59’s modified F-18 Super Hornet F414-GE-100 engine.

“It’s always exciting to see the X-59 come to life on the ground,” said Ray Castner, NASA’s X-59 lead propulsion engineer. “For our team, it’s a moment to pause and appreciate how far this aircraft has come – and how close we are to pushing into the next phase of flight.”

The X-59’s second flight continues the push toward that next phase, with the team closely studying the aircraft’s performance.

“Second flight will look a lot like the first flight,” said Cathy Bahm, NASA’s project manager for the Low Boom Flight Demonstrator project. “We’ll start the flight at a test condition from first flight to ensure X-59 performs as expected after the maintenance phase, then we’ll start the envelope expansion by testing a little higher and faster.”

The flight marks the start of envelope expansion tests for the X-59. After the aircraft reaches a speed of approximately 230 mph at 12,000 feet and its team performs functional checks, it will advance to 260 mph at 20,000 feet.

First flight was the X-59’s biggest leap so far – going from the ground to airborne. Now, envelope expansion will be a gradual process as the aircraft works toward its mission parameters of about 925 mph, or Mach 1.4, at 55,000 feet.

“From here on out, once we’re airborne, we can increase speed and increase altitude in small, measured chunks, looking at things as we go and not getting ahead of ourselves,” Less said. “Eventually we get to supersonic flight – a few more steps – and we’re out to Mach 1.4 at about 55,000 feet,” said Less.

The X-59 is the centerpiece of NASA’s Quesst mission, which aims to usher in a new age of quiet, commercial supersonic flight over land. The X-59 will demonstrate that an aircraft can fly faster than the speed of sound while reducing the typical loud sonic boom to a quieter thump.

Envelope expansion is Phase 1 of Quesst. It will be followed by Phase 2 flight testing to validate the X-59’s acoustic performance. The team will study how the aircraft’s design disperses the shock waves that typically merge into a sonic boom.

After acoustics validation, NASA plans to fly the X-59 over selected U.S. communities to gather data on how people on the ground perceive its quieter sound signature. NASA will share the results with U.S. and international regulators.

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Mar 17, 2026

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Dim Delights in Cancer

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Dim Delights in Cancer

Several bright stars and many background galaxies are visible against a black background.

Another Hubble view of the outskirts of Messier 44 shows a variety of bright stars and many background galaxies.

Credits:
NASA, ESA and C. Scarlata (University of Minnesota – Twin Cities); Processing: Gladys Kober (NASA/Catholic University of America)

Cancer the Crab is a dim constellation, yet it contains one of the most beautiful and easy-to-spot star clusters in our sky: the Beehive Cluster. Cancer also possesses one of the most studied exoplanets: the superhot super-Earth, 55 Cancri e.

Three constellations right to left - Gemini, Cancer, and Leo - with the star cluster known as the Beehive circled in the center of the Cancer constellation. The image also contains notable objects such as the planet Jupiter as seen in March 2026, and stars Castor and Pollux in Gemini, Regulus in Leo, and Procyon in Canis Minor.

Find the M44, the Beehive Cluster, at the center of the Cancer constellation, using nearby stars such as Regulus in Leo, Pollux in Gemini, and Procyon in Canis Minor.

Stellarium Web

Find Cancer’s dim stars by looking in between the brighter neighboring constellations of Gemini and Leo. Don’t get frustrated if you can’t find it at first, since Cancer isn’t easily visible from moderately light-polluted areas. Once you find Cancer, look for its most famous deep-sky object: the Beehive Cluster! It’s a large open cluster of young stars, three times larger than our Moon in the sky. The Beehive is visible to the unaided eye under good sky conditions as a faint, cloudy patch, but is stunning when viewed through binoculars or a wide-field telescope. It was one of the earliest deep-sky objects noticed by ancient astronomers, and so the Beehive has many other names, including Praesepe, Nubilum, M44, the Ghost, and Jishi qi. Take a look at it on a clear night through binoculars. Do these stars look like a hive of buzzing bees? Or do you see something else? There’s no wrong answer, since this large star cluster has intrigued imaginative observers for thousands of years.

The super-Earth exoplanet 55 Cancri e, depicted with its star in this artist’s concept, likely has an atmosphere thicker than Earth’s but with ingredients that could be similar to those of Earth’s atmosphere.

NASA/JPL-Caltech

55 Cancri is a nearby binary star system, about 41 light-years from us and faintly visible under excellent dark sky conditions. The larger star is orbited by at least five planets, including 55 Cancri e (a.k.a. Janssen, named after one of the first telescope makers). Janssen is a “super-earth,” a large rocky world 8 times the mass of Earth, and orbits its star every 18 hours, giving it one of the shortest years of any known planet! Janssen was the first exoplanet to have its atmosphere successfully analyzed. Both the Hubble and retired Spitzer space telescopes confirmed that the hot world is enveloped by an atmosphere of helium and hydrogen, with traces of hydrogen cyanide: not a likely place to find life, especially since the surface is probably scorching-hot rock. NASA’s Exoplanet Travel Bureau allows us to imagine what it would be like to visit 55 Cancri e and other worlds.

How do astronomers find planets around other star systems? The Night Sky Network’s “Wobbles and Transits: How Do We Find Planets Around Other Stars?” activity helps demonstrate both the transit and wobble methods of exoplanet detection. Notably, 55 Cancri e was discovered using the wobble method in 2004, and the transit method confirmed its orbital period in 2011!

Want to learn more about exoplanets? Get the latest NASA news about worlds beyond our solar system at NASA Exoplanets!

Originally posted by Dave Prosper: March 2020

Last Updated by Kat Troche: March 2026

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Wednesday, 18 March 2026