Tag: exploration

Webb takes a look at a strange planetary nebula

9:49 am

Nebula PMR-1
Click for original image.

Cool image time! The two false-color pictures to the right, reduced to post here, were taken by two different infrared cameras on the Webb Space Telescope.

The object, PMR-1, is about 5,000 light years away and has apparently not been studied very much in the past. In 2013 astronomers used the Spitzer Space Telescope to get a first look in the infrared, at a much lower resolution. They also gave this object a nickname, the “Exposed Cranium” nebula. From the Webb press release:

The nebula appears to have distinct regions that capture different phases of its evolution — an outer shell of gas that was blown off first and consists mostly of hydrogen, and an inner cloud with more structure that contains a mix of different gases. Both Webb’s NIRCam (Near-Infrared Camera) and MIRI (Mid-Infrared Instrument) show a distinctive dark lane running vertically through the middle of the nebula that defines its brain-like look of left and right hemispheres. Webb’s resolution shows that this lane could be related to an outburst or outflow from the central star, which typically occurs as twin jets burst out in opposite directions. Evidence for this is particularly notable at the top of the nebula in Webb’s MIRI image, where it looks like the inner gas is being ejected outward.

While there is still much to be understood about this nebula, it’s clear that it is being created by a star near the end of its fuel-burning “life.” In their end stages, stars expel their outer layers. It’s a dynamic and fairly fast process, in cosmic terms. Webb has captured a moment in this star’s decline. What ultimately happens will depend on the mass of the star, which is yet to be determined. If it’s massive enough, it will explode in a supernova. A less massive Sun-like star will continue to shed layers until only its core remains as a dense white dwarf, which will cool off over eons.

The dark lane suggests we are looking at the star’s equator, with the two lobes on either side the material being flung out ward from the poles. It is also possible this is wrong, because the lobes on either side do not have a clear distinct jet-like appearance.

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Dart changed the orbit of the Didymos/Dimorphos binary asteroids around the Sun

2:54 pm

Dimorphos just after impact

When the Dart spacecraft impacted the asteroid Dimorphos in September 2022, it not only shortened Dimophos’ orbit around its companion asteroid Didymos by about 33 minutes while reshaping the asteroid, a new study has found that it also changed very slightly the orbit of both asteroids around the Sun.

The image to the right, annotated to post here, was taken by the Italian LICIACube spacecraft moments after the September 26, 2022 impact.

The research paper describing this research can be found here. From the press release:

The new study shows the impact ejected so much material from the binary system that it also changed the binary’s orbital period around the Sun by 0.15 seconds. “The change in the binary system’s orbital speed was about 11.7 microns per second, or 1.7 inches per hour,” said Rahil Makadia, the study’s lead author at the University of Illinois Urbana-Champaign. “Over time, such a small change in an asteroid’s motion can make the difference between a hazardous object hitting or missing our planet.”

To be precise, the orbital speed was slowed 1.7 inches per hour, which while tiny would mean its solar orbit is now slightly shortened.

The result proves that a similar impact could be used on some asteroids to deflect them from hitting the Earth, though we would need to know a lot about that asteroid prior to launching the mission to accurately predict the orbital change. Otherwise, any impact could be a dangerous crap shoot that could do more harm than good.

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Curiosity looks uphill at its upcoming travels

12:41 pm

Panorama looking up Mount Sharp
Click for original.

Overview map
Click for interactive map.

Cool image time! Since May 2025 Curiosity has been exploring in great detail the boxwork formations located on the lower slopes of Mount Sharp. It is now about to complete those investigations, with the Curiosity science team beginning their planning for moving onward and upward.

The panorama above, enhanced to post here, was taken on March 2, 2026 by the rover’s right navigation camera. It looks uphill along the valley that Curiosity is in toward the mountainous region the rover is targeting. Note that the peak of Mount Sharp is not visible, being more than 25 miles away beyond the horizon and about 15,000 feet higher up.

The blue dot on the overview map to the right mark Curiosity’s present position. The yellow lines indicate roughly the area this panorama covers. The red dotted line marks the rover’s approximate planned route, while the white dotted line indicates Curiosity’s actual travels.

Right now Curiosity is traveling through a geological layer the scientists have dubbed the sulfate unit. The lighter colored hills seen on the horizon have also been identified as sulfate, but believed to be much more pure. The geology there should be very different. Instead of rough and rocky it could be like traveling over soft porous sand. This however is merely a guess on my part, based on imagery of those light-colored hills.

The actual route through those hills however remains unknown. Either the science team has not yet released it, or is still trying to figure out the best way through.

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ESA loses contact with the coronagraph satellite of its duel-satellite Proba-3 mission

9:24 am

The Proba-3 mission
The Proba-3 mission. Click for original.

The European Space Agency (ESA) today announced that engineers have lost contact with the Coronagraph satellite of its duel-satellite Proba-3 mission, and are working now to recover contact.

During the weekend of 14–15 February 2026, an anomaly onboard Proba-3’s Coronagraph spacecraft triggered a chain reaction that led to the progressive loss of attitude (spacecraft orientation) and prevented the entry into safe mode.

Because the spacecraft’s solar panel was no longer facing the Sun, the onboard battery started to discharge quickly. This caused the spacecraft to enter survival mode, when minimum electronics are active and data transmission to the ground is interrupted.

The exact root cause of the anomaly is under investigation, and mission teams and operators have joined forces to attempt to re-establish contact with the spacecraft to recover the situation.

The Coronograph satellite is the heart of this mission. It records the data, available because the Occulter blocks the Sun from view so that the corona, the Sun’s atmosphere, can be seen. Based on this report, it does not look good that the spacecraft can be recovered.

At the same time, the mission has apparently achieved all of its initial goals, and was now on an extended mission.

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New Webb data says asteroid 2024 YR4 will miss the Moon in 2032

2:54 pm

Asteroid 2024 YR4 as seen by Webb in the mid-infrared
Asteroid 2024 YR4 as seen by Webb in the
mid-infrared in April 2025. Click for original image.

New Webb data collected in February has now eliminated any chance the potentially dangerous asteroid 2024 YR4 will hit either the Earth or the Moon when it makes its next close pass on December 22, 2032.

Using data from NASA’s James Webb Space Telescope observations collected on Feb. 18 and 26, experts from NASA’s Center for Near-Earth Object Studies at the agency’s Jet Propulsion Laboratory in Southern California have refined near-Earth asteroid 2024 YR4’s orbit and are ruling out a chance of lunar impact on Dec. 22, 2032. With the new data, 2024 YR4 is expected to pass by the lunar surface at a distance of 13,200 miles (21,200 km).

Earlier less precise data had suggested 2024 YR4 had a 4.3% chance of hitting the Moon in 2032. That chance is now zero. This result is actually disappointing, in that an impact of this asteroid, estimated to be about 200 feet in diameter, would have not only been spectacular, but would have been scientifically useful. We would have been able to observe it closely with many ground- and space-based telescopes, and garnered a lot of useful information about the asteroid, the Moon, and the very nature of impacts.

The impact would have also eliminated the chance this asteroid might hit the Earth in the future. 2024 YR4 orbits the Sun about every four years. Previous calculations suggested another potentially dangerous fly-by of Earth in 2047, but these numbers are unreliable because the orbit will be changed by the 2032 fly-by in ways that cannot be predicted as yet.

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The auroras of Jupiter and Ganymede

11:13 am

According to two different university press releases in the past month, new details have been discovered about the auroras found on Jupiter as well as its largest moon, Ganymede, caused by the interaction of Jupiter’s powerful magnetic field not only with Ganymede’s weak one but with the motion of all four Galilean moons as they orbit the gas giant.

The first study used data from Juno when it made a close fly-by of Ganymede in 2021. It not only showed how the aurora was caused by interaction between the magnetic fields of Jupiter and Ganymede, it found that Ganymede’s auroras were similar to those on Earth.

Similar structures, known as ‘beads’, have been observed in the auroras of Earth and Jupiter, where they are linked to sub-storms and dawn storms, large-scale rearrangements of the magnetosphere that release enormous amounts of energy and produce intense auroral activity,” explains Alessandro Moirano, post-doctoral researcher at LPAP.

Ganymede interacts with Jupiter’s space environment in a similar way to how Earth interacts with the solar wind; therefore, the discovery of auroral patches on Ganymede similar to those on Earth suggests that the fundamental physical process(es) could be generally induced in the coupling between any celestial body, its magnetosphere, and external forces.

The aurora's on Jupiter
The auroral footprints of Io and Europa
on Jupiter

The second study, released yesterday, used the Webb Space Telescope to a get a more detailed look at Jupiter’s auroras, caused as the four Galilean moons — Io, Europa, Ganymede, and Callisto — travel through Jupiter’s powerful magnetic field, causing energetic particles to following Jupiter’s magnetic field lines down to its poles, there creating the auroras.

Webb’s data found that the auroral footprints on Jupiter caused by each moon were different from Jupiter’s own aurora.

However, the footprints created by Io and Europa, did not have the characteristics expected from Jupiter’s main aurora, which contains a lot of hot material. Instead, in one snapshot, they discovered a cold spot within Io’s auroral footprint that registered temperatures much lower than expected, with extraordinarily high densities.

As the data was limited to a single 22-hour window, the results are very uncertain. More observations are planned, covering a longer time period, to see if this phenomenon can be captured again.

All of these results are very tantalizing, but to really get a handle on what is going on will require continuous observations over years, from many spacecraft devoted exclusively to Jupiter. And that isn’t going to happen for quite some time.

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The mysterious spokes in Saturn’s rings

11:59 am

A bent spoke in Saturn's rings
Click for original.

Cool image time! When Voyager-1 did its fly-by of Saturn in December 1980, its cameras captured something in the gas giant’s rings that no one had predicted or expected, spokes of brightness pointing outward along the surface of the rings at right angles to the planet. Even more puzzling, these spokes actually appeared to rotate around Saturn, always pointing away from it.

The picture to the right, cropped, reduced, and enhanced to post here, was taken on March 7, 2007 by the Saturn orbiter Cassini. It shows a close-up of one such spoke, though in this case it is bent. From the press release:

A bright spoke extends across the unilluminated side of Saturn’s B ring about the same distance as that from London to Cairo. The background ring material displays some azimuthal (i.e., left to right) asymmetry. The radial (outward from Saturn) direction is up in this view. A noticeable kink in the spoke occurs very close to the radius where ring particles orbit the planet at the speed of Saturn’s magnetic field. Such a connection is most intriguing to scientists studying these ghostly ring phenomena.

If gravity alone were affecting the spoke material, there would be no kink and the entire spoke would be angled toward right, like the bottom portion. That it bends to the left above the kink indicates that some other force, possibly related to the magnetic field, is acting on the spoke material. The shape might also indicate that the spoke did not form in a radial orientation, thus challenging scientists’ assumptions about these features.

In other words, the spokes exist because of multiple factors, some still unknown, that cause these streaks of brightness in the rings. For some reason, the millions of tiny ice particles that comprise the rings are brightened along these spokes, and it isn’t just gravity that is causing it.

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Charon’s surface, completely unlike Pluto

1:09 pm

Panorama of part of Charon's surface
Click for full resolution. For original images go here, here, and here.

Charon

Cool image time! The panorama above, created from three images taken by New Horizons as it began its July 14, 2015 fly-by of the Pluto-Charon double planet system (found here, here, and here), show in close-up one specific swath of Charon cutting across its equatorial regions.

The true color global image of Charon to the right shows the approximate area covered by the panorama above. For scale, Charon has a diameter of about 750 miles, about half that of Pluto. For clarity I have rotated the panorama so that it more closely aligns with the rectangle of global image.

One of the most remarkable discoveries made during New Horizons’ fly-by was how completely different Pluto and Charon appeared, despite their likely formation together at the same time and in the same location of the early solar system. While Pluto had frozen nitrogen seas and water ice mountains floating at the shores, Charon more resembled Mercury, cratered with many large ridges and canyons criss-crossing its service. Both planets appear to be icy, but somehow Charon appears to lack the large differentiated variety of materials seen on Pluto.

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Old and new optical space telescopes team up to view the Cat’s Eye

9:39 am

Cat's Eye Nebula as seen by both Hubble and Euclid
Click for original images.

Astronomers using both NASA’s long established Hubble Space Telescope and Europe’s new Euclid space telescope have produced new optical/infrared images of the Cat’s Eye planetary nebula.

Those images are to the right, cropped, reduced, and sharpened to post here. The Hubble image at bottom shows the complex structure of the nebula itself, located about 4,400 light years away and believed created by the inner orbital motions of a binary star system that act almost like the blades in a blender, mixing the material thrown off by one or both of the stars as they erupt in their latter stages of life.

In Euclid’s wide, near-infrared, and visible light view, the arcs and filaments of the nebula’s bright central region are situated within a halo of colorful fragments of gas zooming away from the star. This ring was ejected from the star at an earlier stage, before the main nebula at the center formed. The whole nebula stands out against a backdrop teeming with distant galaxies, demonstrating how local astrophysical beauty and the farthest reaches of the cosmos can be seen together with Euclid.

Euclid has a primary mirror 1.2 meters in diameter, about half that of Hubble. Though it can’t zoom in with the same resolution, its view is as sharp since it is in space above the atmosphere. It thus provides a wider view, which in this case helps provide a larger context to the detailed close-up view provided by Hubble.

In many ways Euclid is Hubble’s replacement, produced by the European Space Agency, as NASA and the American astronomy community has not been able to get together to build their own new optical orbiting telescope.

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Two moons of Saturn against its majestic rings

12:25 pm

Mimas and second moon against Saturn's rings
Click for original image.

Cool image time! The picture to the right, cropped and enhanced to post here, was taken on December 23, 2005 by Cassini as it orbited Saturn.

The larger cratered moon is Mimas, known best for the single giant crater that dominates one hemisphere. I have not been able to identify the brighter but smaller moon.

Note the pattern within the largest bright central ring in the background. It is possible this is an optical illusion, but it is also possible this pattern is inherent in the ring itself. Other images show similar patterns that scientists have concluded were real.

This image was part of a set of eight images all taken in the space of less than two minutes, as the smaller moon moved from the lower left to the upper right and was eclipsed by Minas as it did so. Below are four of those pictures, showing the sequence.
» Read more

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Rocket Lab completes in-space commissioning of two Escapade Mars orbiters

8:38 am

Built by Rocket Lab for NASA and launched in November 2025, the company has now completed the in-space commissioning of two Escapade Mars orbiters and is about to hand operations over to the University of California Berkeley Space Sciences Laboratory (UC-Berkeley).

With both spacecraft now fully commissioned and successfully operating at the Earth–Sun Lagrange Point 2 (L2), Rocket Lab is preparing to hand over operational control to [UC-Berkeley], who will lead science operations at L2 and prepare the mission for its cruise to Mars.

Under contract from [UC-Berkeley], Rocket Lab was selected to design, build, and provide commissioning operations of the two high delta-V Explorer-class interplanetary spacecraft for ESCAPADE. Rocket Lab moved from concept to launch readiness in just over three years, proving commercial collaboration can deliver important science key to supporting future human and robotic exploration of Mars on ambitious schedules and for significantly smaller budgets than typical interplanetary missions. This speed was made possible through Rocket Lab’s vertically integrated spacecraft production, with key components including solar arrays, reaction wheels, propellant tanks, star trackers, radios, avionics, and flight software designed and built in-house.

Launched from Cape Canaveral Space Force Station in November 2025, the twin ESCAPADE spacecraft, known as Blue and Gold, completed spacecraft commissioning and executed two precise trajectory correction maneuvers, placing both spacecraft into their loiter trajectory near L2, approximately 1.5 million kilometers from Earth.

Both spacecraft will be sent on their way to Mars in December 2026 when orbital mechanics between the Red Planet and Earth are right for the journey. Once in Mars orbit the two orbiters will allow for a three-dimensional study of the interaction between the solar wind and Mars’ atmosphere.

Though this is a NASA-funded mission, note that it was built a commercial company and operated not by NASA but by a university. For this reason, it was not only built fast and at a low cost, it uses an innovative flight path that allowed it to be launched anytime and wait in orbit for the right moment to go to Mars. This last innovation provides for a lot more flexibility.

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Mars’ fast moving gigantic lava floods

2:23 pm

A Martian crater broken by flowing lava
Click for original image.

Cool image time! The picture to the right, rotated, cropped, and reduced to post here, was taken on December 12, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The science team labels this a “crater interrupted by flow.” And what a flow! This unnamed 1.4-mile wide crater was not only filled and partly buried by the flow, that flow was so strong it cut through the crater’s rim at two points, refusing to let that rim block it in any way.

The flow in this case is lava, coming down from the Tharsis Bulge where four of Mars’ biggest volcanoes arose. And that flow was quite vast, as the nearest of those volcanoes, Arsia Mons, is almost 800 miles away. Because of Mars’ relative light gravity, about 39% that of Earth’s, lava on Mars can flow across large distances in a very short time. It might have only taken a few weeks for that flow to cover that 800 miles.
» Read more

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China outlines plans for manned space program

10:26 am

China’s state-run press today outlined a short update on the status of its manned space station program as well as its planned manned lunar landing, still targeting a 2030 launch.

For the space station, these are its upcoming plans:

China is scheduled to launch two crewed missions and one cargo spacecraft mission for its space station operation in 2026, according to the China Manned Space Agency (CMSA). An astronaut from the Hong Kong or Macao special administrative region is expected to carry out a space station flight mission as early as this year, the CMSA noted.

One astronaut from the Shenzhou-23 crew will conduct a year-long in-orbit stay experiment, the CMSA said.

I am willing to bet that China is planning an even longer station mission that will break Valeri Polyakov’s 14.5 month record mission, set in the 1990s on Mir.

As for China’s lunar landing plans, nothing new was announced:

China is targeting a crewed lunar landing by 2030. The development of major flight products, including the Long March-10 carrier rocket, the Mengzhou crewed spacecraft, and the Lanyue lunar lander, is proceeding smoothly. Key tests have been completed, including the zero-height abort test for the Mengzhou spacecraft, the landing and takeoff test for the Lanyue lunar lander, the static fire test and the low-altitude demonstration and validation test for the Long March-10 rocket system, and the maximum dynamic pressure escape test for the Mengzhou spacecraft system.

In 2026, the country will intensify efforts to advance the construction of supporting facilities and equipment for the lunar mission at the Wenchang Spacecraft Launch Site in southern Hainan Province, as well as the development of ground support systems.

China has not yet outlined a program of missions leading up to that lunar landing. Like Apollo and now Artemis, it makes sense to do low orbit rendezvous and docking tests of these various spacecraft before heading to the Moon. It also makes sense to do these same tests first in lunar orbit, before landing. Expect China to announce such a program soon, for launch in the 2027-2029 timeframe.

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Europe’s Jupiter probe Juice releases its first image of interstellar comet 3I/Atlas

9:18 am

Comet 3I/Atlas as seen by Juice
Click for original image.

The European Space Agency’s (ESA) probe Juice, presently on its way to Jupiter, yesterday released its first image of interstellar comet 3I/Atlas from the data it gathered in November 2025 but only now has been able to send back to Earth.

That picture is to the right, cropped and reduced to post here. From the press release:

[T]he science camera on ESA’s Jupiter Icy Moons Explorer (Juice) shows interstellar comet 3I/ATLAS spewing dust and gas. The tiny nucleus of the comet (not visible) is surrounded by a bright halo of gas known as the coma. A long tail stretches away from the comet, and we see hints of rays, jets, streams and filaments. The inset in the image shows the same data, but processed to highlight the coma structure.

As also noted in the release, though this comet is from outside our solar system, “its behaviour is completely in line with that expected from a ‘normal’ comet.”

The picture was taken on November 6, 2025, just seven days after the comet made its closest pass to the Sun. At that time Juice took 120 images, which could not be sent back until now because the Sun was in the way. The science team is presently analyzing that data, and plans a full release of its work next month.

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The shoreline of Pluto’s frozen nitrogen sea

11:10 am

The shoreline of Pluto's frozen nitrogen sea
Click for full resolution. For original
images go here and here.

Cool image time! In my continuing exploration of the New Horizons’ image archive, I keep finding things that I do not remember ever seeing before. The two New Horizon pictures used to create the panorama to the right (here and here) were taken by the spacecraft only thirteen minutes before its closest approach to Pluto at 7,800 miles on July 14, 2015. It shows the Al-Idrisi mountains — thought to be made up of frozen ice as hard as granite — and the frozen nitrogen sea that pushes against those mountains and squeezes them into their jumbled shape. For scale, the image is estimated to be fifty miles wide.

In December 2015 the science team released a small section of one of two images, focused specifically at that nitrogen sea shoreline, noting:

Great blocks of Pluto’s water-ice crust appear jammed together in the informally named al-Idrisi mountains. Some mountain sides appear coated in dark material, while other sides are bright.

The team however did not release this wider panorama produced by both images, which I think gives a better perspective of what we are looking at.

I posted an even wider shot of this shoreline on January 29, 2026. If you look closely at that picture, you can spot the features to the right, but much smaller seen from a greater distance.

For the larger context, below is a wide shot of Pluto indicating the part of the planet where this image is located.
» Read more

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The weird landscape of Mars’ death valley

11:19 am

Taffy terrain
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and enhanced to post here, was taken on October 28, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The science team labels this “bands near mesa,” an apt description. What we are looking at is a geological feature unique to Mars, but also unique to only one particular place on Mars, the planet’s death valley, the place in Hellas Basin with the lowest relative elevation of any spot on Mars.

The feature is called taffy terrain. According to a 2014 paper, the scientists posit that this material must be some sort of “a viscous fluid,” naturally flowing downward into “localized depressions.” Those localized depressions however happen to also be at the very basement of Mars.

Note how in some spots the bands appear to have been stripped off, exposing small hollows in which dust has become trapped over time to form ripple dunes.
» Read more

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Webb tracks Uranus’ atmosphere over 15 hours

9:27 am

Uranus and its atmosphere
Click for original image.

Using the Webb Space Telescope, astronomers on January 19, 2025 were able to observe Uranus for fifteen straight hours, tracking the atmosphere’s temperature and structure more completely than ever before.

You can read the peer-reviewed paper here. The false color image to the right, reduced to post here, is just one slice of that dataset. We are looking down at Uranus’ pole, as the rotational tilt is so severe the planet rotates on its side as it orbits the Sun. The grey circles on the outside are the planet’s faint rings. The orange blobs I think are aurora that rotate around the pole at high latitudes, as shown in this video. The orange represents the upper atmosphere.

Led by Paola Tiranti of Northumbria University in the United Kingdom, the study mapped out the temperature and density of ions in the atmosphere extending up to 5,000 kilometres above Uranus’s cloud tops, a region called the ionosphere where the atmosphere becomes ionised and interacts strongly with the planet’s magnetic field. The measurements show that temperatures peak between 3,000 and 4,000 kilometres, while ion densities reach their maximum around 1,000 kilometres, revealing clear longitudinal variations linked to the complex geometry of the magnetic field.

…Webb’s data confirm that Uranus’s upper atmosphere is still cooling, extending a trend that began in the early 1990s. The team measured an average temperature of around 426 kelvins (about 150 degrees Celsius), lower than values recorded by ground-based telescopes or previous spacecraft.

Two bright auroral bands were detected near Uranus’s magnetic poles, together with a distinct depletion in emission and ion density in part of the region between two bands (a feature likely linked to transitions in magnetic field lines). Similar darkened regions have been seen at Jupiter, where the geometry of the magnetic field there controls how charged particles travel through the upper atmosphere.

There is great uncertainty in these conclusions, mostly because the observations are for such a short time. It is like trying to understand the Earth’s climate after looking at it for only one day.

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Saturn’s moon Enceladus, as seen during Cassini’s last close fly-by

1:22 pm

Enceladus as seen during Cassini's last close fly-by
Click for original.

Cool image time! On December 19, 2015 the Saturn orbiter Cassini made its last close fly-by of the moon Enceladus, known best for the many geysers detected on its surface venting water and other carbon-based materials.

The picture to the right, reduced and enhanced to post here, shows that the entire face of this
Saturn’s moon Enceladus, as seen during that fly-by. The moon itself is only about 310 miles across.

Its icy surface is evident, as are the many fractures, some meandering almost like rivers. Interestingly, for some reason there are a lot more craters in the lower hemisphere, while the upper hemisphere is more completely covered with fractures.

The black outline indicates the approximate area captured by the two close-up images below.
» Read more

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Webb imaged a star before it went supernova

11:14 am

Webb detection of a supernova progenitor
Click for original image.

One of the biggest challenges facing astronomers for more than four centuries has been the detection of a star prior to its going supernova. Until very recently, no such detection had ever happened, and so astronomers could only guess at the kind of stars or binary systems that might result in these gigantic stellar explosions.

In recent years the improvement in telescopes, both in orbit and on the ground, has produced some successes, whereby the progenitor star was imaged in archival imagery and found after the explosion. The sample however has been small, and the data limited to only a few wavelengths.

Now, the Webb Space Telescope has made its first detection of a supernova progenitor, in the infrared. That image is to the right, showing the star prior to the June 2025 supernova explosion.

By carefully aligning Hubble and Webb images taken of NGC 1637, the team was able to identify the progenitor star in images taken by Webb’s MIRI (Mid-Infrared Instrument) and NIRCam (Near-Infrared Camera) in 2024. They found that the star appeared surprisingly red – an indication that it was surrounded by dust that blocked shorter, bluer wavelengths of light. “It’s the reddest, most dusty red supergiant that we’ve seen explode as a supernova,” said graduate student and co-author Aswin Suresh of Northwestern University.

This excess of dust could help explain a long-standing problem in astronomy that could be described as the case of the missing red supergiants. Astronomers expect the most massive stars that explode as supernovas to also be the brightest and most luminous. So, they should be easy to identify in pre-supernova images. However, that hasn’t been the case.

One potential explanation is that the most massive aging stars are also the dustiest. If they’re surrounded by large quantities of dust, their light could be dimmed to the point of undetectability. The Webb observations of supernova 2025pht support that hypothesis.

You can read the peer-reviewed paper here [pdf].

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First visual detection of another star’s heliosphere

9:38 am

A baby star's heliosphere
Click for full image.

Using both the Hubble Space Telescope and the Chandra X-ray Observatory, astronomers have made the first visual detection of another star’s heliosphere, in both X-rays and in the infrared.

The image to the right, cropped to post here.

Astronomers have nicknamed the HD 61005 star system the “Moth” because it is surrounded by large amounts of dust patterned similarly to the shape of a moth’s wings when viewed through infrared telescopes. The wings are formed from material left behind after the formation of the star, similar to the Kuiper Belt in our own solar system. Observations of these wings with NASA’s Hubble Space Telescope showed that the interstellar matter surrounding HD 61005 is about a thousand times denser than that around the Sun.

The wings are the points to the left and right. The star’s young heliosphere, which they dub an “astrosphere,” is the purple glow above and below. From the caption:

In this composite image of HD 61005 in the inset, X-rays from Chandra (purple and white) have been combined with infrared data from Hubble (blue and white). Chandra reveals a bright source of X-rays in the center of the image, which is the star itself surrounded by the star’s astrosphere. The wing-like structure sweeping away from the star in the infrared image is dusty material that remained behind after the formation of the star. These wings have been swept backwards as they fly through space.

As this star and its solar system are very young, what we have is a very dusty accretion disk interacting with a very temperamental baby star.

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