Tag: astronomy

Chandra data finds the Milky Way is bigger in size than previously believed

1:11 pm

The Milky Way is bigger than we thought
Click for original movie.

Using X-ray data from both the X-ray space telescopes Chandra and XMM-Newton, scientist now think the Milky Way is bigger in size than previously believed, with its three outer arms winding around the galactic center at a greater distance.

The two artist conceptions to the right show the difference before and after. The top image shows the previously conceived positions of the three outer arms on the right. The bottom image shows the new position as estimated by this data, about 10% farther out from the Milky Way’s center with the arms more widely spaced.

The researchers used three different gamma-ray bursts to determine the distances to three spiral arms in the Milky Way. In order of increasing distances from the Galactic Center, they are the Perseus, the Outer, and the Outer Scutum-Centaurus arms. Along the direction of one of the bursts, they found that both the Outer and Outer Scutum-Centaurus arms are about 10% more distant than astronomers previously thought.

“The differences are small, but any revision of these distances is important because they are so fundamental for understanding our galaxy,” said co-author Ilaria Fornasiero, who was a PhD student in the same program as the leading author. “For example, this could mean that astronomers have to revise estimates of the mass of the galaxy, because that affects how wide the arms stretch.”

There is a lot of uncertainty in this result. Because we are inside the Milky Way, we really cannot see what it looks like. In fact, though they know it is a spiral galaxy, astronomers are not even sure what classification it falls into. Many studies say it is a barred spiral, but the size and magnitude of that bar is unconfirmed. In this study it appears they considered the bar less prominent.

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Astronomers: We might be experiencing a shower of comets from the distant Oort cloud due to a close pass of another star 2.5 million years ago

1:18 pm

The uncertainty of science: Using computer models and the somewhat sparse data about the distant Oort cloud on the outer fringes of our solar system (from 2,000 to 200,000 astronomical units [au] away) and combining that with the data from the Gaia space telescope that mapped precisely the motions and distances of billions of Milky Way stars, astronomers now posit that the close pass of another star about 2.5 million years ago perturbed the Oort cloud and thus produced the shower of comets that humanity has been experiencing for the last few thousand years.

HD 7977 is a still nearby Sun-like star in the constellation Cassiopeia whose close passage was discovered by the Gaia mission. Approximately 2.5 million years ago, the orbits of the Sun and HD 7977 brought the two stars close together, but exactly how close is still an open question. Gaia data suggest they passed within 4000-25000 astronomical units of one another. Now, Kaib and Raymond have shown that the orbits of long-period comets suggest HD 7977 came within 6000-10000 AU of our Sun, setting off a major shower of new comets into the inner solar system.

You can read the preprint paper here [pdf].

These results are filled with many uncertainties of course. For one, the actual distance for HD 7977’s close pass is not well constrained. The margin of error is large, so that the star might have not done anything at all. Second, our map of the Oort cloud is very uncertain. In fact, it exists at this time only in theory, as it has never been directly observed. Astronomers hypothesize its existence based on the orbits of the long period comets that they have documented for the past few centuries, all coming from that distant region. So while it appears to exist, that existence remains unproven.

These uncertainties thus make the conclusions of this paper interesting but unconfirmed. Nonetheless, they are fascinating, because they are strongly suggestive, and hint at the impact of the galaxy and its stars on the evolution of our solar system itself. That impact is real, though tracing its history is difficult because of the vast time scales and distances. It appears the Gaia data and computers are giving us a first glimpse into that past history.

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Astronomers discover two exoplanets as dense as cotton candy

9:40 am

The observed transits of TOI-791 c.
The observed transits of TOI-791 c by different telescopes
during its 232 day orbit. Figure 9 from the paper.

Using a combination of ground- and space-based telescopes, astronomers have now discovered two exoplanets in the same solar system that have a deas dense as cotton candy.

You can read their paper here. From the NASA press release:

Data from NASA’s TESS (Transiting Exoplanet Survey Satellite) mission has revealed two new “super-puff” planets, giant worlds so light that their density is comparable to cotton candy. Scientists calculate that these Jupiter-sized planets—named TOI-791 b and TOI-791 c—are the “puffiest” worlds ever found.

The planets orbit a Sun-like star named TOI-791 that is approximately 1,113 light years away from Earth. The TESS mission first detected the planets by watching for repeated dips in TOI-791’s brightness, a telltale sign that a planet is transiting, or passing in front of, a star. Further study revealed two large planets with unusual features.

TOI-791 b is nearly the same size as Jupiter but contains just 3.0 percent of Jupiter’s mass. TOI-791 c is even larger than Jupiter but contains just 5.9 percent of Jupiter’s mass.

The data for determining both planet’s density came from follow-up observations using a telescope based in Antarctica. Both planets have long orbits, 139 and 232 days respectively, so these observations took place over a period of eight years, in order to capture multiple orbital transits.

One interesting tidbit: Though the data suggests both planets are spherical, this is not confirmed with certainty. Overall, the nature of such puffy planets is not really understood at this time.

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Scientists: Interstellar Comet 3I/Atlas is very old, as much as 12 billion years old

12:51 pm

Webb data
Click for original image.

Based on spectroscopic data obtained by the Webb Space Telescope in the past year as interstellar Comet 3I/Atlas zipped through our solar system, a team of scientists have now concluded that its make-up suggests it is extremely old, as much as 12 billion years old, which means it was formed in the very early universe not that long after the Big Bang.

You can read their paper here [pdf]. The graph to the right was published by NASA of the infrared spectroscopic data produced by the Webb Space Telescope that supports this conclusion. That data shows the comet was lacking in isotopes commonly found today, while enriched in isotopes expected only in the early universe. From the paper’s abstract:

[W]e report isotopic measurements of the interstellar comet 3I/ATLAS, which reveal an elemental composition unlike any Solar System body. The water in 3I/ATLAS is enriched in deuterium, at a level of D/H = (0.98 ± 0.06)%, which is more than an order of magnitude higher than in known comets, while its range of 12[Carbon]/13[Carbon] ratios (141–191 for CO2 and 123–172 for CO) exceeds typical values found in the Solar System, as well as nearby interstellar clouds and protoplanetary disks.

Such extreme isotopic signatures indicate formation at temperatures ≲ 30 K in a relatively metal-poor environment. When interpreted with respect to models for Galactic chemical evolution, the carbon isotopic composition implies that 3I/ATLAS may have accreted as long ago as 12 billion years, following a period of intense, early star formation. 3I/ATLAS thus represents a preserved fragment of an ancient planetary system.

As the scientists add in what I think is an understatement, “Its distant origin in space and time makes 3I/ATLAS a uniquely-valuable object studies tool for Galactic archaeology.”

That the comet is still remarkable similar in many other ways to comets in our solar system also tells us that the formation processes that form all solar systems are somewhat common. The solar system in which Comet 3I/Atlas formed was different from ours only that it formed when the universe was young, and thus somewhat different in make-up. Otherwise the processes were the same.

At the same time, Comet 3I/Atlas has given us a window into the early universe, and suggests future interstellar comets will do the same. And there will be future interstellar comets, because we are now developing the observational tools to see them as they routinely fly past on a regular basis.

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Scientists skeptical of dark energy fight back!

9:06 am

Will cosmologists every enter?
Will cosmologists ever enter?

The uncertainty of science: In apparent direct response to the June 11, 2026 press release by cosmologists claiming that their data is correct and that the universe’s expansion is accelerating in the early universe and thus dark energy must exist, a different team of scientists today issued their own press release and research paper stating that the evidence of that acceleration is faulty and based upon a false assumption about supernovae.

The original discovery of dark matter and the acceleration was based on the brightness of a certain type of supernova in the early universe, which also assumed that brightness was always the same for every explosion. The new research says otherwise.

The team analysed the supernovae from the Pantheon+ dataset, one of the most comprehensive catalogues of its kind, and incorporated a recently proposed correction that takes into account the age of the stars that eventually produce these supernova explosions. They also checked whether the inferred acceleration of the expansion rate is indeed the same in every direction, as is assumed in the standard cosmological model. “There is increasing evidence that the brightness of Type Ia supernovae depends on the age of the stars they come from,” said Professor Sarkar, a co-author of the study. “If this effect is not accounted for, it can lead to the erroneous conclusion that the expansion rate is accelerating.”

After applying the correction, the researchers found that the data no longer support a picture of a uniformly accelerating universe. Instead, their analysis suggests that cosmic expansion is overall slowing down rather than speeding up.

Their conclusion is blunt: “There is thus no evidence for isotropic accelerated expansion of the Universe, which can be ascribed to either a Cosmological Constant or more general dark energy.”

In other words, there is solid disagreement within the cosmological community about the existence of dark energy. Some believe it exists, based on the supernova data. Some do not, because the data depends on too many assumptions about those supernovae that further observations suggest are wrong.

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Astronomers discover an asymmetrical radio galaxy distorted wildly as it plows into the surrounding galactic medium

9:49 am

Distorted radio galaxy
Figure 1 from the paper. Click for original.

Using ground-based radio telescopes, astronomers have now discovered a very strange asymmetrical radio galaxy squashed into a gigantic arc almost two million light years across as the galaxy pushes its way into the surrounding material of an even more gigantic galactic cluster.

In RAD-BAARG [the name they have given the galaxy], the researchers say one of the jets appears to interact with a large bow shock-like structure formed as the host galaxy falls through the surrounding hot gas toward a nearby cluster of galaxies. Similar to the shockwave formed ahead of a supersonic aircraft, a galaxy moving faster than the speed of sound in the surrounding intracluster medium can compress the ambient gas and generate a large-scale shock front.

The radio-emitting plasma from RAD-BAARG appears to illuminate this otherwise extremely faint structure, making it visible in low-frequency radio images, according to the team. The western side of the source contains a narrow jet feeding a sector-shaped emission region and a giant arc-like feature extending over nearly 560 kiloparsecs (1.8 million light years).

On the opposite side, the jet develops a distorted S-shaped morphology followed by a faint offset tail extending to almost 600 kiloparsecs. The overall structure suggests strong interaction between the radio plasma and the surrounding large-scale environment.

You can read their published paper here. The images to the right are figure 1 from that paper. The top image is just the radio data. The bottom image shows the contours of that radio data over the optical view. The cross marks the location of object’s host galaxy, as seen in the optical.

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Astronomers discover a third galaxy devoid of dark matter

12:22 pm

Galaxy DF9
Click for original image.

The uncertainty of science: Using the Keck telescope in Hawaii, astronomers have discovered a galaxy that apparently has no dark matter, the third such galaxy discovered.

The galaxy, dubbed DF9, is shown to the right. It is part of a region that includes the other two galaxies with no dark matter, suggesting all three were formed in linked circumstances.

The team used Keck Observatory’s Keck Cosmic Web Imager (KCWI) to measure the motions of stars inside DF9 by analyzing the light emitted across different wavelengths. Those measurements revealed that DF9 has a mass of only about 100 million Suns, consistent entirely with the galaxy’s visible matter. If the galaxy contained a typical amount of dark matter, astronomers would expect it to be about 100 times more massive.

Dark matter was invented by astronomers in the 1960s to explain the inexplicable fast rotation of stars in the outer fringes of every galaxy they looked at, much faster than accounted for by the visible mass of each galaxy. That fast rotation suggested there was a lot more matter there that could not be seen, as much as one quarter of all mass according to some models. This unseen matter was then labeled “dark matter”, though even three-quarters of a century later it still remains undetected directly.

That these galaxies have no dark matter poses a difficult problem. At present the scientists are trying to come up with scenarios for creating these galaxies without it, but I suspect they will be hard-pressed to come up with any theory that convinces anyone.

I can’t help wondering if the problem isn’t the fast rotation of the stars, but the observations themselves. Maybe there is something we are missing or are unable to detect, because of the vast distances and faint nature of the light. Either way, dark matter, there or not, remains one of the big fundamental mysteries of cosmology.

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A galaxy as seen by Hubble and Webb

9:23 am

A galaxy seen by Hubble and Webb
Click for original image.

Cool image time. The picture to the right, cropped and reduced to post here, was taken on March 20, 2026 in a coordinated observations by both the Hubble and Webb space telescopes.

This March 20, 2026, image of Messier 64, or the Black Eye Galaxy, is a composite view from NASA’s Hubble Space Telescope and James Webb Space Telescope. It shows Messier 64 captured at near- and mid-infrared wavelengths by Webb, while Hubble’s image shows the galaxy in ultraviolet, visible, and near-infrared light.

Messier 64 is characterized by its bizarre internal motion. The gas in the outer regions of this spiral galaxy is rotating in the opposite direction from the gas and stars in its inner regions. This strange behavior may be the result of a merger between M64 and a satellite galaxy over a billion years ago.

The red in this image is dust, as the galaxy gets its nickname from the dark streak that wraps around its nucleus on its left side. In optical that streak is dark. Here Webb’s infrared view sees it in false color red.

READERS: It appears that it is a very slow news day today. Other than SpaceX’s IPO, which is on-going and too soon to post any reports, I can so far find nothing much of great significance on which to report.

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Evidence of supernova remnant near the center of the Milky Way?

10:21 am

Supernova remnant near the Milky Way's center
Click for original image.

Using two X-ray space telescopes, astronomers now think they have detected evidence of a supernova remnant very close to the center of the Milky Way.

You can read their paper here [pdf]. The image to the right is a composite of optical (the stars), radio (the red nebula), and Chanda’s X-ray data (the blue nebula). From the press release:

The evidence for the new supernova remnant, located about 26,000 light-years from Earth, comes from X-ray data from Chandra and XMM-Newton. The X-ray data reveals a “blob” of X-ray emission [indicated by blue] that may come from the remains of a massive star that self-destructed as a supernova, buried within the larger cloud of expanding gas.

The location of this suspected supernova remnant in the image is [that blue region]. It is in bubble of gas [the surrounding larger and smaller red objects] that has had electrons stripped away from hydrogen — called an “H II region” — surrounding a massive, young star. If this is indeed a supernova remnant, then it is expanding at about two million miles per hour and is at least about 1,700 years old.

,..The long filaments seen in the radio image are caused by energetic particles travelling along magnetic fields that are mostly directed perpendicular to the plane of the galaxy.

According to the paper, this supernova remnant is found on the western edge of a vast energized gas cloud called the Central Molecular Zone (CMZ), 1,600 to 1,900 light years across, that spans the Milky Way’s center. The features seen in the image above are part of a feature on the CMZ’s western edge called Sagittarius C, which apparently has not been studied as much as other parts of the CMZ.

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Astronomers find another quasar in the early universe that really shouldn’t be there

9:28 am

The uncertainty of science: Using archival data from the WISE space telescope, astronomers have now identified another unexpected quasar in the early universe, only 850 million years after the Big Bang, that also flickers in several wavelengths.

The quasar’s flicker enabled the researchers to determine that, surprisingly, the ancient quasar’s whirlpool of gas and dust, known as an accretion disk, resembled a flat pancake, similar in shape to that of more modern-day quasars.

Their findings add to a longstanding mystery in cosmology: Why do supermassive black holes exist so early in the universe’s history? Physicists have assumed that a flat accretion disk reflects a relatively mature black hole that is in a calm and stable state. Black holes that are just starting to form, like those in the very early universe, should be more unsettled systems, with accretion disks that appear more puffy and chaotic.

The flat accretion disk around this very early quasar heightens the mystery of how supermassive black holes can grow and mature in a very short amount of cosmic time.

They estimate the quasar energy output is equivalent to about 12 trillion suns. Its flickering, ranging about 20% in power, makes it the first such flickering quasar found this early in time. Such early quasars however are not unique. Astronomers have found about 200, all of which should not exist, based upon present Big Bang cosmology. There simply hasn’t been enough time for them to evolve, based on present theories of galactic formation.

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Astronomers measure weight of supermassive black hole 10 billion light years away

9:13 am

In a new record for the farthest measurement yet achieved (10 billion light years away), astronomers have now used the Webb Space Telescope obtain a reasonably accurate measurement of the mass of supermassive black hole in the early universe, estimated to be six billion times the mass of our Sun.

The stars orbiting Sag A*
The stars orbiting Sag A* at the center of our own
galaxy, the Milky Way. Click for original image.

The black hole’s mass is about 6 billion times that of the sun, and is being observed at a time when the universe was only about 3 billion years old, about a quarter of its current age, offering unprecedented details into black holes in the early universe.

To find this, the team used data from NASA’s James Webb Space Telescope to track the motion of stars orbiting around the otherwise invisible black hole to measure its mass. Though the technique – known as stellar dynamics – has been used to measure dormant black holes in galaxies much closer to Earth, this is the first time it has been used to weigh one located such a great (cosmological) distance away.

For comparison, the Milky Way’s central super-massive black hole, Sagittarius A* (pronounced “A-star”), has been estimated at four million solar masses, using this same technique. The graphic to the right shows the various stars orbiting Sagittarius A* that have been tracked now for several decades in the infrared. As their orbits are refined, astronomers can use those orbits to determine the mass of the central object.

The scientists have now been able to do the same with this galaxy ten billion light years away. These observations however are certainly preliminary, and will be refined in the coming decades as more data is obtained.

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The wind speeds on seven exoplanets also suggest presence of magnetic fields

10:54 am

Astronomers using two different ground-based telescopes were able to measure the wind speeds on seven different gas giant exoplanets, and found the speeds also suggested the presence of planetary magnetic fields, the first time such magnetic fields have been deduced on an exoplanet.

In the study, the researchers investigated the wind speeds on seven exoplanets orbiting different stars. These are gas giants similar to Jupiter, which are very close to their star. Elspeth Lee explains: “The rotation of the planets was synchronized with their orbits by the tidal forces of the parent star. Just as we only ever see one side of the moon, these planets always have one side facing the star. Thus, a glowing hot day side and a permanently dark night side have formed on the planets. The extreme temperature differences in turn lead to the generation of extremely strong winds.”

…The research team was able to show that wind speeds of around 7,200 km/h to over 25,000 km/h prevail on the exoplanets. For comparison: the fastest winds measured on Jupiter reach speeds of around 1,500 km/h.

The data showed that the hotter the planet, the slower the wind, the opposite of what was expected. The scientists believe that each planet’s magnetic field is acting to brake the winds, with the hotter planets likely having more powerful fields.

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Webb detects methane being released by interstellar comet 3I/Atlas

9:21 am

Comet 3I/Atlas's methane as seen by Webb
Comet 3I/Atlas’s methane as seen by Webb.
Click for full image.

Using the Webb Space Telescope, astronomers have now detected methane in the cloud of material released by the interstellar comet 3I/Atlas as it zipped past the Sun last fall.

The observations were taken using Webb’s MIRI (Mid-Infrared Instrument) on two separate dates as the comet traveled back out of our solar system after whipping around the Sun (post-perihelion). The first observation occurred Dec. 15 to 16, when the comet was about 205 million miles from the Sun. This was followed by a second observation Dec. 27, when the comet was about 236 million miles from the Sun.

For the first time on an interstellar visitor, Webb directly detected methane gas. Methane is highly volatile, meaning it sublimates from solid ice into a gas very easily. Its delayed appearance in comet 3I/ATLAS suggests it was buried below the comet’s top surface layer and protected from sublimation until heat from the comet’s close pass to the Sun reached deeper parts of the icy subsurface. The amount of methane relative to water found is surprisingly high, with few similar analogs in our own solar system.

Webb’s observations also confirmed that comet 3I/ATLAS remains unusually rich in carbon dioxide, releasing far more carbon dioxide relative to water when compared to typical solar system comets.

You can read their peer-reviewed paper here [pdf]. This new data confirms that Comet 3I/Atlas is not from our solar system, as its make-up is sufficiently different from solar system comets to show this. It also gives us a hint as to the solar system it came from. At the same time, the comet’s behavior is remarkably similar to solar system comets, suggesting our solar system evolved much like others.

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An active galaxy peered at by Webb in the infrared

10:57 am

M77 as seen by Webb
Click for original image.

Cool image time! The false-color infrared image to the right, cropped and reduced to post here, was taken by the Webb Space Telescope as part of a research of “massive, nearby, star-forming galaxies.” It shows Messier 77 (M77), a barred spiral galaxy located 45 million light-years away.

What makes the image cool are the eight diffraction spikes, which are an artifact of Webb and its camera.

Called diffraction spikes, they are created because the intense light from the unresolved AGN is bent (“diffracted”) very slightly at the edges of Webb’s hexagonal mirror panels and around one of the struts that hold up its secondary mirror. This distinctive six-plus-two-pointed pattern is the same for any image taken by Webb. For diffraction spikes to appear, the light source has to be very bright and very concentrated, so they’re most often seen on stars. But in some galaxies, as here, the nucleus is bright and compact enough to make diffraction spikes appear as well.

In the case of M77, the nucleus is especially bright.

At the heart of M77 is a compact region filled with hot gas that handily outshines the rest of the galaxy put together, even overcoming the light-gathering capacity of Webb’s cameras. This is an active galactic nucleus (AGN), and it’s powered by M77’s central supermassive black hole, which is eight million times as massive as our Sun. Gas in the galaxy’s central regions is pulled by the strong gravity into a tight and rapid orbit around the black hole, where it crashes together and heats up, releasing tremendous amounts of radiation.

The result is this very cool image that also highlights a great deal about galaxies and their evolution.

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Using Webb astronomers think they have detected daily weather changes on exoplanet

9:27 am

The data confirming explanet's existence from 2014 paper
Figure 1 from the 2014 paper confirming exoplanet’s existence.

Using the Webb Space Telescope’s infrared spectroscopic data astronomers believe they have detected the daily weather changes on exoplanet WASP-94A b, a hot gas giant about half the mass of Jupiter that orbits its star every four days.

Observations revealed that mornings and evenings on WASP-94A b have extremely different weather patterns: Mornings are riddled with clouds made of magnesium silicate, a common mineral found in rocks, while the evening has clear skies.

The star itself is about 700 light years away, and is known to have two exoplanets circling it.

The scientists proposed two explanations for their data. Either strong winds are clearing the air in the evening, or the clouds are the equivalent of morning fog on Earth that naturally dissipates as the day brightens.

Note that there is great uncertainty with these results, as we are only getting a very limited view from 700 light years away. In a sense, our knowledge of these exoplanets is comparable to what we knew of our own solar system’s planets prior to the space age. Once we got our first close looks at the planets almost everything we thought we knew beforehand turned out to be either wrong or misguided, due to the limited nature of the data.

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An amoeba in space more than a light year in size

12:59 pm

An amoeba in space more than a light year in size
Click for original image.

Time for another cool image. The picture to the right, cropped and reduced to post here, was released today by the science team of the 8.1 meter Gemini North telescope on Mauna Kea in Hawaii. It provides a close-up view of the central blob that forms NGC 1514, a planetary nebula located about 1,500 light years away and nicknamed the Crystal Ball Nebula by Gemini’s PR team.

They might think it resembles a crystal ball, but to my eye this is an amoeba undulating in weightlessness.

Planetary nebulae form when a low- or intermediate-mass star ejects its outer layers near the end of its life, forming a somewhat spherical cloud of gas. They typically have smoother, spherical shapes, making the Crystal Ball Nebula unique for its bumpy shells of gas. As the central star casts away this gas, its inner core is exposed. Radiation from the core energizes the gas, giving it a scorching temperature and chromatic glow. The Crystal Ball Nebula, for example, has an estimated temperature of 15,000 K.

…While it may appear in this image as if there is a single shining light source at the heart of the Crystal Ball Nebula, as Herschel saw, it actually contains two stars. These two stars orbit each other with a period of around nine years — the longest known for any binary pair within a planetary nebula. Scientists believe that one of these stars, which was once several times more massive than our Sun, released its outer layers while in the throes of death. As the progenitor star and its binary companion orbit each other, they mold the expanding shell of gas with their strong, asymmetrical winds, forming the lumpy layers we see today.

The analogy I like to use for this process is that of a blender. The two stars act like the blender’s blades, mixing the outflowing gas from the stars into these spectacular shapes.

The Webb Space Telescope took its own infrared image of this nebula, and showed that its is surrounded by two larger rings of material, also expanding outward.

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Psyche approaches Mars

8:30 am

Mars as seen by Psyche
Click for original image.

The asteroid probe Psyche is now approaching Mars for a May 15, 2026 fly-by that will slingshot it out to the metal asteroid Psyche in 2029.

The image to the right, cropped and expanded to post here, was taken on May 3, 2026 when the spacecraft was still about three million miles away.

The observation was acquired by the multispectral imager instrument’s panchromatic or broadband filter, with an exposure time of just 2 milliseconds. Even with this very short exposure time, the crescent is extremely bright and parts of the image are oversaturated. The light seen here is sunlight reflected off the surface of Mars and also scattered by dust particles in its atmosphere. Because the quantity of dust in the atmosphere can vary rapidly over time, the anticipated brightness of the crescent was hard to predict before this early image was acquired.

The dustiness of Mars leads to sunlight being scattered by its atmosphere, making the crescent appear to extend farther around the planet than if it had no atmosphere (as with our Moon).Of note, on the right side of the extended crescent, there appears to be a gap, which coincides with the planet’s icy north polar cap. The cap is currently in winter and mission specialists hypothesize that seasonal clouds and hazes may be forming in that region, possibly blocking the atmospheric dust’s ability to scatter sunlight like it does elsewhere around the planet.

Though the spacecraft had had a thruster issue last year, all seems well at this time.

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Katalyst completes final ground testing of its Swift rescue spacecraft

8:01 am

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

The orbital servicing startup Katalyst has now successfully completed the final ground testing of its Swift rescue spacecraft, dubbed LINK, that it hopes will be able to catch the Gehrels-Swift Telescope and raise its orbit, thus saving the telescope.

During vibration testing at NASA Goddard, engineers mimicked the shaking the spacecraft will experience during its launch from a Northrop Grumman Pegasus rocket. In the footsteps of Swift itself and NASA’s upcoming Nancy Grace Roman Space Telescope, the Katalyst team also used NASA Goddard’s Space Environment Simulator for thermal vacuum testing.

Once the air was pumped out of this 27-foot-wide chamber, LINK experienced space-like hot and cold temperature extremes. The team also practiced firing the satellite’s three xenon-powered ion thrusters and deployed one of the arms.

After some more testing in Arizona, the spacecraft will be integrated in June onto Northrop Grumman’s Pegasus rocket — the last one in its inventory — and launched later that month.

Katalyst has never done this before. It was preparing LINK as a demo mission when NASA requested bids for saving Swift. It proposed reconfiguring LINK for that purpose, and won the contract in September 2025, only eight months ago.

If this mission succeeds it will be a big feather in Katalyst’s cap.

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New data says interstellar Comet 3I/Atlas IS different from comets in our solar system

10:42 am

Using spectroscopic data from the ALMA telescope in Chile, astronomers have determined that interstellar comet 3I/Atlas is enriched in deuterium (sometimes called “heavy water”), with quantities as much as 30 times that found in ordinary solar system comets and 40 times that found in Earth’s oceans.

You can read the peer-reviewed paper here. From its abstract:

3I/ATLAS shows a deuterium enrichment exceeding Earth’s ocean value by more than a factor of about 40 and typical Solar System cometary values by more than a factor of about 30. The elevated deuterium enrichment points to water that formed under colder, less irradiated conditions and from less thermally processed material, consistent with an origin in a planetary system that formed under different physical and chemical conditions than our own.

In other words, the conditions in which Comet 3I/Atlas’ solar system formed were very different from those when our own solar system formed.

This conclusion is wonderful, but it raises more questions than it answers. Since we do not know how old the comet is, nor do we really know where it came from, there is little else we can glean from this result, other than it proves the conditions when solar systems form can vary widely.

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Hubble looks at the Trifid Nebula again

9:59 am

Trifid Nebula as seen by Hubble
Click for original image.

Cool image time! The picture to the right, cropped to post here, was taken by the Hubble Space Telescope and released today. It shows a small section of the Trifid Nebula, located about 5,000 light years away.

This location has been imaged numerous times in the past by Hubble. The area shown illustrates some fundamental aspects of stellar and nebula formation. The dark area in the lower right is a thick dust cloud. Several energetic O and B supermassive stars are out of view at the top. The radiation from these stars (indicated by the blue), is hitting that dust cloud and literally destroying it. It appears that the foreground “horn” exists because a larger object is blocking the radiation, allowing dust to survive in the background.

I have no explanation for the background “horn”.

This new image was taken in parallel with an image of the entire Trifid Nebula, taken by the new Rubin Telescope in Chile. Though Rubin cannot see with the same resolution as Hubble, its image is quite worthwhile viewing.

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