Tag: science

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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Sunspot update: Sunspot activity tumbles in February, including the 1st blank days since ’22

10:53 am

The uncertainty of science! It is the start of the month, and thus time for another sunspot update, using NOAA’s monthly graph of the sunspot activity on the Earth-facing hemisphere, updated by NOAA to include the activity in February but annotated with extra information by me to illustrate the larger scientific context.

Last month I lambasted NOAA’s solar science panel for its consistently failed predictions, and made a tentative prediction of my own, suggesting the ramp down to solar minimum might not be occurring as they had predicted in April 2025.

This month I can lambast myself, because the Sun in February saw a significant drop in sunspots, including three consecutive days in which the Sun was blank of spots, for the first time since 2022. This drop supports the NOAA panel prediction and makes my prediction look foolish, but it also suggests the ramp down is continuing to go faster than predicted.
» 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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Early notes of Galileo discovered in margins of Ptolemy’s most famous book

11:20 am

A researcher reviewing the text of a 16th century printing of Claudius Ptolemy’s most famous book, The Almagest (in which he outlined his theory that the Earth stood at the center of the universe), was astonished this January to discover previously unidentified notes in the handwriting of Galileo in the book’s margins.

As [historian Ivan Malara flipped through the pages, he spotted something out of place. Someone had transcribed Psalm 145 on an otherwise blank page—in handwriting reminiscent of a very, very famous Tuscan astronomer.

That book, Malara came to realize, had been extensively annotated by none other than Galileo Galilei. Malara’s discovery, described in a paper now under review at the Journal for the History of Astronomy, promises new insights into one of the most famous ideological transitions in the history of science: the moment when Earth was thrust from the center of our universe.

The article at the link tries to makes the absurd and false claim that “many historians’ typical portrayal of Galileo as being motivated by philosophy or even political savvy, not careful math. ‘He has been presented as a big-picture sort of guy—not interested in the nitty-gritty technical details of astronomy,’ says James Evans, a historian of astronomy at the University of Puget Sound.” The article does this to suggest these newly discovered notes will profoundly change that interpretation.

That interpretation is wrong however. Anyone who has read any histories or biographies of Galileo (as I have) knows this portrayal is false. It is very clear from all his work that Galileo was very evidence-based, focused on the data and facts — the nitty-gritty technical details — to determine the larger picture. And these newly discovered notes confirm this:

Galileo’s notes, perhaps written around 1590, or roughly 2 decades before his groundbreaking telescope observations of the Moon and Jupiter, reveal someone who both revered and critically dissected Ptolemy’s work. And they imply, Malara argues, that Galileo ultimately broke with Ptolemy’s cosmos because his mastery of the traditional paradigm’s reasoning convinced him that a heliocentric system would better fulfill Ptolemy’s own mathematical logic.

Fascinating stuff. I can’t wait to read the final paper.

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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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New analysis suggests Moon’s magnetic field shifted multiple times from weak to strong to weak

10:03 am

The uncertainty of science: A new analysis of Apollo lunar samples suggests that the Moon’s magnetic field actually shifted back and forth from strong to weak, with it being weak most of the time.

The problem scientists have had since the Apollo missions is that the Apollo samples, which all came from the relatively flat mare regions, tended to exhibit evidence of a strong past magnetic field, even though the Moon’s size and make-up suggested its field should have always been weak. This new research offers a solution:

The research team analysed the chemical makeup of a type of lunar rock – known as the Mare basalts – and found a new correlation between their titanium content and how strongly magnetised they are. Every lunar sample which had recorded a strong magnetic field also contained large amounts of titanium – and the samples containing less than 6 wt.% titanium were all associated with a weak magnetic field.

This suggests that the formation of high-titanium rocks and the generation of a strong lunar magnetic field are linked. The researchers believe that both were caused by melting of titanium-rich material deep inside the Moon, temporarily generating a very strong magnetic field.

Because the Mare basalts were an ideal landing site for the Apollo missions, due to being relatively flat, the astronauts brought back far more of the titanium-rich basalts (containing evidence for a strong magnetic field) than are representative of the lunar surface. As a result, large numbers of these rocks have been analysed by scientists back on Earth, and this was previously interpreted to mean that the lunar magnetic field was strong for long periods of its history.

Instead, the limited number of samples, all from the same regions, biased the conclusions. The scientists predict that future missions to more places on the Moon will confirm their findings.

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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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Pluto’s splotched surface

12:30 pm

Pluto's splotched surface
For original images go here and here.

Cool image time! The panorama above was created using two photographs (found here and here) taken by New Horizons during its close fly-by of Pluto on July 14, 2015. It looks at Pluto’s western limb, well lit by the Sun, from a distance of approximately 60,000 miles.

I pulled these images from the New Horizons’ archive specifically because I don’t remember ever seeing them publicly released by the science team. More important, they show a surface far more alien than other more well-known New Horizon pictures. Are those round splotches impact craters or some alien type of volcanic caldera? Note also the vertical cracks that appear to divide this terrain near the center.

It would be a serious mistake to make any conclusions. In the emptiness of the outer solar system, the impact rates are going to be far less than in the inner solar system, so assuming impacts is dangerous. Pluto meanwhile has an alien surface of frozen nitrogen seas often filled with floating mountains of frozen water ice. For it to also produce weird volcanic eruptions of nitrogen, sublimating away like bubbling tomato sauce when it is simmering, is quite possible.

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The dimmest galaxy yet found

9:57 am

The dimmest galaxy yet found
Click for original image.

The uncertainty of science: Using ground-based and orbiting telescopes, astronomers think they have identified what might be the dimmest galaxy yet discovered, revealed almost entirely not from its stars but from the four globular clusters that reside within or near it.

The image to the right, cropped and sharpened to post here, shows that galaxy, dubbed CDG-2, along with those four globular clusters. From the press release:

To confirm one of the dark galaxy candidates, astronomers employed a trio of observatories: the NASA/ESA Hubble Space Telescope, ESA’s Euclid space observatory, and the ground-based NAOJ Subaru Telescope in Hawaii. Hubble’s high-resolution imaging revealed a close collection of four globular clusters in the Perseus galaxy cluster, 300 million light-years away. Follow-up studies using Hubble, Euclid, and Subaru data then revealed a faint, diffuse glow surrounding the star clusters – strong evidence of an underlying galaxy.

“This is the first galaxy detected solely through its globular cluster population,” said David. “Under conservative assumptions, the four clusters represent the entire globular cluster population of CDG-2.”

Preliminary analysis suggests CDG-2 has the luminosity of roughly 1 million Sun-like stars, with the globular clusters accounting for 16% of its visible content.

The scientists next claim that 99% of the galaxy’s mass is made up of dark matter, a material no one has yet detected except for the gravitational influence its invisible mass imposes on visible objects. It appears the astronomers don’t believe the mass that has been detected is sufficient to hold this galaxy together, and thus they need dark matter to explain its existence.

I simply wonder if the distances involved simply make the matter hard to see.

No matter. This is a cool discovery, because it tells us there is much out there hidden in the darkness we will always find difficult if not impossible to detect.

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UAE extends mission of its Al-Amal Mars orbiter

8:57 am

Deimos with Mars in the background
Al-Amal’s 2023 image of Deimos, the first good
picture of the moon ever taken. Click for full movie.

The United Arab Emirates (UAE) yesterday announced it is extending the mission of its Al-Amal Mars orbiter (“Hope” in English) to 2028, significantly beyond its initial planned mission of two years.

Launched in July 2020, the Hope Probe successfully entered Mars orbit in February 2021 after a seven-month interplanetary journey, marking a historic achievement as the first Arab nation to reach the Red Planet. Originally designed as a two-year mission to observe and study Mars’ atmosphere, the probe has far exceeded expectations. Since reaching Mars, it has gathered around 10 terabytes of scientific data, shared through more than a dozen datasets with research institutions worldwide.

The probe itself was mostly built by American engineers and organizations, as part of a deal to train UAE students. Once in operation around Mars, the UAE and those students took over almost all operations. It orbits Mars in a very wide orbit, allowing it to study global weather and atmosphere conditions, such as dust storms.

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Pluto’s floating mountains of frozen ice

10:18 am

Pluto's floating mountains
Click for original image.

Cool image time! The picture to the right, rotated, cropped, and sharpened to post here, was taken by New Horizons on July 14, 2015 when it made its close fly-by of Pluto.

The picture looks at the part of Pluto that was close to sunset. Hence the mountain’s long dramatic shadow. The raw image webpage provides little information, including a scale of 0.0 meters, which means nothing. My guess is that these mountains could be several hundred to several thousand feet high based on data from other New Horizon mountain images, but that is a pure guess.

What we think we know is that these mountains are likely made of ice, which at Pluto’s eternally cold environment is as hard as granite. We also think we know that they float on a layer of frozen nitrogen, but because that nitrogen can sublimate into gas when Pluto’s climate warms as its orbit brings it closer to the Sun, the foundation of these mountains is quite unstable. They can roll and drift about, even if they are the size of the Appalachian mountains in the eastern U.S.

I continue to delve into the New Horizons’ archive, and have discovered a trove of quite amazing pictures that hadn’t been featured by the science team during the fly-by. Pluto really is an alien place. Stay tuned, there is more to come!

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A sinuous Martian ridge of uncertain origin

10:06 am

A sinuous ridge of uncertain origin
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on July 21, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It was posted today by the camera team as a captioned image, with the caption as follows:

The sinuous ridge is approximately 10 meters wide and several kilometers long. The floor surrounding this ridge has been eroding laterally, forming pits and circular features suggestive of removal (sublimation) of subsurface ice. However, landforms such as channels or moraines that might suggest the presence of water or ice are lacking, so the ridge itself does not appear to have formed by fluvial or glacial processes.

Perhaps this curious feature is an exhumed dike formed from magma emanating from Alba Mons in subsurface fractures.

Alba Mons is a gigantic shield volcano to the west.
» Read more

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Engineers have shut down the Gehrels-Swift space telescope in a last attempt to save it

8:07 am

Katalyst's proposed Swift rescue mission
Katalyst’s proposed Swift rescue mission.
Click for original image.

In order to delay the moment the orbit of the Gehrels-Swift Observatory decays — to increase the chance a rescue mission can get there in time — engineers have now stopped almost all scientific observations temporarily.

On Feb. 11, NASA’s Neil Gehrels Swift Observatory temporarily suspended most science operations in an effort to reduce atmospheric drag and slow the spacecraft’s orbital decay. Halting these activities will enable controllers to keep the spacecraft in an orientation that minimizes drag effects, extending its time in orbit in anticipation of a reboost mission.

“Normally, Swift quickly turns to view its targets — especially the fleeting, almost daily explosions called gamma-ray bursts — with multiple telescopes,” said principal investigator S. Bradley Cenko at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Swift’s Burst Alert Telescope will continue to detect gamma-ray bursts, but the spacecraft will no longer slew to observe targets with its other telescopes.”

…To maximize the orbit boost’s chances of success, Swift’s average altitude needs to be above about 185 miles. As of early February, Swift’s average altitude had fallen below about 250 miles.

NASA has awarded the orbital repair startup Katalyst the contract to rescue Gehrels-Swift, but the company has a very challenging mission. It got the contract only a few months ago, in September 2025, and is refitting its planned satellite rescue demo mission to save the space telescope instead. The graphic to the right shows how its rescue robot will approach and grab Gehrels-Swift to raise its orbit, but it must be noted that the telescope has no planned grapple points, and Katalyst’s robot has never done this before.

Moreover, the robot will be launched using the last Pegasus rocket in Northrop Grumman’s warehouse, with a launch scheduled now for sometime this summer. That means Katalyst has had to go from contract award to launch in less than a year, a pace that up until now has been unheard of in the space business. If successful however Katalyst will once again demonstrate the benefits of the capitalism model, whereby NASA buys the product from the private sector rather than building it itself. Left to NASA, this rescue mission would never happen.

And even if Katalyst’s rescue fails, that the company could get it built and launched in such a short time still proves the value of the capitalism model. Freedom and capitalism and competition at least made the attempt possible.

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A sculptured Martian landscape

12:24 pm

Weird Martian landscape
Click for original.

Cool image time! The picture to the right, cropped and sharpened to post here, was taken on December 4, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The science team labels this landscape “olivine-rich plains”, which is a magnesium iron silicate mineral of some industrial value that is quite common on Earth. Its presence here suggests there could be other valuable minerals in this region.

I post the image because the landscape is so weird and beautiful. The orange color suggests these ridges are covered with dust, if not made of dust entirely. The small areas with a greenish tint that appear to mostly appear on north-facing cliffs could be frost, except this is in the southern hemisphere where north-facing cliffs get more sunlight. As it was autumn when this picture was taken frost is an unlikely explanation.

More likely the green indicates exposures of bedrock or coarser boulders.
» Read more

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Hubble eyes the Egg Nebula

10:48 am

Hubble eyes the Egg Nebula
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Cool image time! The picture to the right, reduced to post here, was taken by the Hubble Space Telescope as part of a study of “preplanetary nebula,” the initial stages of a planetary nebula that forms as some star types begin dying. From the caption:

Many preplanetary nebulae are relatively dim and hard to spot. They are made of layers of gas ejected by the star, but that star is not yet hot enough to ionise the gas and cause it to glow. The Egg Nebula is relatively unique, easily visible as a sparkling jewelled egg in space. Powerful beams of starlight blast out of the inner cloud, two a-side, giving a breathtaking illumination to this cosmic structure. Fast-moving outflows of hot molecular hydrogen also emerge from within the dust cloud, visible just at the base of the searchlight beams. These outflows glow with infrared light, which is shown in this image by orange highlights.

The central cloud of dust is surrounded by concentric rings, themselves made up from thin, faint arcs of gas. These were created by successive outbursts from the central star, which ejected a little more material from its outer surface every few hundred years. The beams of starlight are reflected by these layers of gas, creating an appearance like ripples on the surface of water. The way that gas molecules reflect and scatter light gives a bluish colour to the arcs. The reflected starlight reveals important details about the central star, which is impossible to view directly in its dusty shell.

Many planetary nebula get their spectacular shapes because they have a binary star system in their center, that act like the blades in a blender as they circle each other, mixing the materials the stars’ eject to form those shapes. Because of those surrounding shells, it is often impossible to determine with the nebula has a single central star, or a binary system.

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How Saturn’s moon Enceladus causes an aurora on Saturn

9:38 am

Enceladus orbiting Saturn
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Using data collected by the orbiter Cassini while it orbited Saturn more than a decade ago, scientists now think they have mapped out how the moon Enceladus interacts with Saturn’s magnetic field and helps create an aurora in Saturn’s polar regions.

You can read the paper here. The artist rendering to the right comes from the press release, and shows that interaction. From that release:

The study, published in the Journal of Geophysical Research: Space Physics, shows how wave structures, known as ‘Alfvén wings’, travel like vibrations on a string along magnetic field lines connecting Enceladus to Saturn’s pole. The initial ‘main’ Alfvén wing is reflected back-and-forth both by Saturn’s ionosphere and the plasma torus that encircles Enceladus’s orbit, resulting complex and structured system. By using a multi-instrumental approach, researchers were able to show that the influence of Enceladus extends over a record distance of over 504,000 km – more than 2,000 times the moon’s radius.

…As well as the large-scale structures, the team found evidence that turbulence teases out the waves into filaments within the main Alfvén wing. This fine-scale structure helps the waves bounce off Enceladus’s plasma torus and reach the high-latitudes in Saturn’s ionosphere where auroral features associated with the moon form.

The white haze below Enceladus in the graphic represents the material that comes out of the “tiger stripe” fractures near its south pole.

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A lava tube on Venus?

9:18 am

Theorized lava tube on Venus

The uncertainty of science: Scientists in Italy have reanalyzed the radar data of Venus by the Magellan orbiter from 1990 to 1992 and concluded that at least one open pit on the side of a shield volcano might be the entrance to a underground lava tube.

You can read their paper here [pdf]. The graphic above comes from figures 2 and 3 of their paper, with the radar image of the pit to the right, and the cartoon to the left their interpretation of that radar data. From the abstract:

Between 1990 and 1992, the Synthetic Aperture Radar (SAR) instrument on board the Magellan spacecraft mapped the Venusian surface. By leveraging a SAR imaging technique developed for detecting and characterizing accessible subsurface conduits in the proximity of skylights, we analysed
the Magellan radar images in locations where there is evidence of localized surface collapses. Our analyses reveal the existence of a large and open subsurface conduit in the Nyx Mons region. This feature is hypothesized to be a pyroduct, characterized by a diameter of about 1 km, a roof thickness of at least 150 m and an empty void height of no less than 375 m. The conduit extends in the subsurface for at least 300 meters from the skylight.

To strengthen their conclusions, which are based on a LOT of assumptions, the scientists also compared this radar data with radar data taken of similar-sized lava tube skylights on Earth.

Their conclusion is reasonable, as Venus is a planet of volcanoes, with more than a million detected in radar data. Lava tubes should exist. Nonetheless, their interpretation of the radar data is very uncertain, and must be viewed with a great deal of skepticism.

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India picks landing site for its Chandrayaan-4 lunar sample return mission

10:22 am

Landing sites at the Moon's South Pole

Scientists at India’s space agency ISRO have now picked [pdf] a preliminary landing site for its planned Chandrayaan-4 lunar sample return mission, scheduled to launch in 2028.

[Four] sites of Mons Mouton area was fully characterised with respect to terrain characteristics using high resolution OHRC multiview image datasets and it was found that 1km x 1km area around MM-4 (-84.289, 32.808) contains the less hazard percentage, mean slope of 5°, Mean height of 5334m and most number of hazard free grids of size 24m x 24m. Hence MM-4 can be considered for the potential site of Chandrayaan-4 mission.

The study area of all four sites is indicated on the map to the right by the red dot labeled “Chandrayaan-4”. This mountain, Mons Mouton, is essentially a flat plateau between the numerous craters in the south pole region (many with permanently shadowed craters). Intuitive Machines second lander, Athena, attempted a landing there last year, and tipped over, as did that company’s first lander, Odysseus, both indicated in green. Astrobotic’s Griffin lander (yellow) is targeting this mountain also, hopefully to launch later this year.

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One of Cassini’s first close-up images of Saturn’s rings

12:48 pm

The rings of Saturn
Click for original image.

Cool image time! My exploration of the Cassini image archive continues. The picture to the right, reduced and enhanced to post here, was taken on May 2, 2005 by Cassini soon after it moved into a close orbit of Saturn where it could get high resolution images of Saturn’s rings. This is one of the first.

This is also a raw image that has not been calibrated or validated, to use the science team’s terms. Thus, the white dots scattered across the image could be artifacts that need to be cleaned up, not examples of Saturn’s many moons.

Regardless, the image illustrates the incredible delicacy of these rings, despite the fact that they are gigantic, spanning almost 45,000 miles in width, with a thickness ranging from 30 to 1,000 feet. And yet, there are so many distinct rings they almost resemble an old-fashioned vinyl record.

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Pluto’s implausible atmosphere, as seen in 2015 by New Horizons

2:07 pm

Pluto's implausible atmosphere
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Cool image time! The picture to the right, cropped to post here, was taken on July 14, 2015 by the camera on the New Horizons probe as it flew past Pluto, the only time a human craft has gotten close to this distant planet. From the link:

These high phase angle images show many artifacts associated with scattered sunlight; the Sun was less then 15 degrees from the center of the LORRI frame for these observations. But the outline of Pluto and its hazy atmosphere are also visible.

To see the atmosphere the light from the planet itself has been blocked out.

What is implausible about Pluto’s atmosphere is the location of the planet, about 3.7 billion miles from the Sun, out in the nether reaches of the solar system. At that distance sunlight is very weak, and produces very little energy. And yet, there is enough energy here to produce an atmosphere of mostly nitrogen gas, with trace amounts of metane and carbon monoxide. Scientists think this atmosphere only exists when Pluto is closer to the Sun in its somewhat oblong orbit, and freezes out the rest of the time. As Pluto was just retreating in 2015 from that closest approach in the last two decades of the 20th century, New Horizons could detect its presence.

But then, we really can’t be sure if this atmosphere truly vanishes when the planet is farthest from the Sun, as we have only so far observed 96 years in Pluto’s 248-year orbit.

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