Tag: science

Astronomers detect a seven-hour-long gamma ray burst, the longest many times over

4:40 pm

Very long GRB

Astronomers have detected the longest gamma ray burst (GRB) ever measured, lasting more than seven hours when most GRBs at most last mere seconds.

The image to the right was taken by the Hubble Space Telescope and is taken from figure 1 of the peer-reviewed paper [pdf]. The two hash marks indicate the location of the GRB, within the outer reaches of its host galaxy and inside one of its spiral arms, based on other data. The data also suggested the host galaxy is “massive [100 billion solar masses], dusty, and [an] extremely asymmetric system that is consistent with two galaxies undergoing a major merger.”

The GRB’s long length means that none of the known theories for its origin work. From the press release:

Of the roughly 15,000 GRBs observed since the phenomenon was first recognized in 1973, only a half dozen come close to the length of GRB 250702B. Their proposed origins range from the collapse of a blue supergiant star, a tidal disruption event, or a newborn magnetar. GRB 250702B, however, doesn’t fit neatly into any known category.

From the data obtained so far, scientists have a few ideas of possible origin scenarios: (1) a black hole falling into a star that’s been stripped of its hydrogen and is now almost purely helium, (2) a star (or sub-stellar object such as a planet or brown dwarf) being disrupted during a close encounter with a stellar compact object, such as a stellar black hole or a neutron star, in what is known as a micro-tidal disruption event, (3) a star being torn apart as it falls into an intermediate-mass black hole — a type of black hole with a mass ranging from one hundred to one hundred thousand times the mass of our Sun that is believed to exist in abundance, but has so far been very difficult to find. If it is the latter scenario, this would be the first time in history that humans have witnessed a relativistic jet from an intermediate mass black hole in the act of consuming a star.

None of these proposed explanations are confirmed. What is known is that this GRB was unique in all ways, defying all theoretical expectations.

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A small galaxy with lots of massive stars

9:54 am

A small galaxy with many massive stars
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken by the Hubble Space Telescope and released this week as the European Space Agency’s (ESA) Hubble picture of the week.

This dwarf galaxy, 13 million light years away, is called Markarian 178 (Mrk 178). Though much smaller than the Milky Way, it is packed with massive stars. From the caption:

While the bulk of the galaxy is blue owing to an abundance of young, hot stars with little dust shrouding them, Mrk 178 gets a red hue from a collection of massive stars, which are especially concentrated in the brightest, reddish region near the galaxy’s edge. This azure cloud is home to a large number of rare objects called Wolf–Rayet stars. Wolf–Rayet stars are massive stars that are casting off their atmospheres through powerful winds. Because Mrk 178 contains so many Wolf–Rayet stars, the bright emission lines from these stars’ hot stellar winds are etched upon the galaxy’s spectrum. Particularly ionised hydrogen and oxygen appear as a red colour to Mrk 178 in this photo, observed using some of Hubble’s specialised light filters.

Massive stars enter the Wolf–Rayet phase just before they collapse into black holes or neutron stars. Because Wolf–Rayet stars last for only a few million years, researchers know that something must have triggered a recent burst of star formation in Mrk 178. At first glance, it’s not clear what could be the cause — Mrk 178 doesn’t seem to have any close galactic neighbours that could have stirred up its gas to form new stars. Astronomers believe that it was triggered by the interaction with a smaller satellite, as revealed by the presence of low surface brightness tidal features detected around Mrk 178 in deep imaging acquired with the Large Binocular Telescope.

And yet, these observations do not see this small satellite galaxy. It has either been completely absorbed into Mrk 178, or maybe this theory for explaining this dwarf galaxy’s make-up is flawed.

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Perseverance moves west, into the barren hinterlands beyond Jezero Crater

1:56 pm

Perseverance looking west
Click for full resolution. Original images can be found here and here.

Overview map
Click for interactive map.

Cool image time! The panorama above was created using two pictures taken on December 4, 2025 (here and here) by the navigation camera on the Mars rover Perseverance. The view I think is looking west, away from the rim of Jezero Crater, which now lies behind the rover to the east.

The blue dot on the overview map to the right marks Perseverance’s position when it took this picture. The yellow lines indicate my rough guess as to the area covered by the panorama. The white dotted line marks the actual route the rover has taken, while the red dotted line the original planned route.

As I noted in my previous Perseverance update in mid-November, the science team has apparently decided to revise the route, abandoning initial plan of going back uphill towards the rim and instead travel downhill into the hills beyond. This is a region that orbital data has suggested might be rich in minerals, making it a prime mining location for future colonists. My guess is that the science team decided they needed to get there, that they had enough data from the rim and that it was now more important to get to the western mineralogy.

Though I am sure they are using the highest resolution orbital images from Mars Reconnaissance Orbiter (MRO) to guide them, the Perseverance team has not yet upgraded its interactive location map to show those details in this western region. Thus, the map in this area is fuzzy and not as detailed.

The team has also not published its revised planned route, so there is no way to guess where the rover will go next. It does appear however that it is finally leaving Jezero Crater for good.

And as all recent pictures from Perseverance, these images show this Martian landscape to be utterly barren, its hills and valleys softened by dust and eons of erosion from the very thin Martian wind. This is an alien place, though it has the potential with human ingenuity to bloom if we have the courage to try.

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New data strengthens the conflict in the observed value for the universe’s expansion rate

11:49 am

Graphic showing the conflict
Click for original.

The uncertainty of science: New research using a combination of ground- and space-based telescopes has not only failed to resolve the difference between the two values observed for the Hubble constant (the expansion rate of the universe), it actually confirms that conflict.

The graphic to the right nicely illustrates the conflict. Observations from the early universe come up with a value of 67-68 kiloparsecs per second per megaparsec for the Hubble constant. Observations from the present universe, including these new more precise measurements, come up with a value of 73-74. From the press release:

A team of astronomers using a variety of ground and space-based telescopes including the W. M. Keck Observatory on Maunakea, Hawaiʻi Island, have made one of the most precise independent measurements yet of how fast the universe is expanding, further deepening the divide on one of the biggest mysteries in modern cosmology.

Using data gathered from Keck Observatory’s Cosmic Web Imager (KCWI) as well as NASA’s James Webb Space Telescope (JWST), the Hubble Space Telescope (HST) the Very Large Telescope (VLT), and European Organisation for Astronomical Research in the Southern Hemisphere (ESO) researchers have independently confirmed that the universe’s current rate of expansion, known as the Hubble constant (H₀), does not match values predicted from measurements from the universe when it was much younger.

Cosmologists call this conflict “the Hubble Tension”, a absurd fake term expressly designed to hide the fact that they have no idea what’s going on. It isn’t “tension”, it is a perfect example of good observations coming up with contradictory data that no theory can explain.

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New images of interstellar Comet 3I/Atlas

9:56 am

New Hubble image of 3I/Atlas
Click for original.

Juice image of 3I/Atlas
Click for original.

Both NASA and the European Space Agency (ESA) yesterday released new photos of the interstellar comet 3I/Atlas.

First, NASA released the image on the right, taken on November 30, 2025 by the Hubble Space Telescope. At the time the comet was about 178 million miles away. It clearly shows the comet’s coma of material, surrounding a bright nucleus at the center. The streaks are background stars.

Next, the mission team for Europe’s Juice probe, on its way to Jupiter, released one small portion of a picture taken by its navigation camera. That picture is the second to the right.

During November 2025, ESA’s Jupiter Icy Moons Explorer (Juice) used five of its science instruments to observe 3I/ATLAS. The instruments collected information about how the comet is behaving and what it is made of. In addition, Juice snapped the comet with its onboard Navigation Camera (NavCam), designed not as a high-resolution science camera, but to help Juice navigate Jupiter’s icy moons following arrival in 2031.

Though the data from the science instruments won’t arrive on Earth until February 2026, our Juice team couldn’t wait that long. They decided to try downloading just a quarter of a single NavCam image to see what was in store for them. The very clearly visible comet, surrounded by signs of activity, surprised them.

Not only do we clearly see the glowing halo of gas surrounding the comet known as its coma, we also see a hint of two tails. The comet’s ‘plasma tail’ – made up of electrically charged gas, stretches out towards the top of the frame. We may also be able to see a fainter ‘dust tail’ – made up of tiny solid particles – stretching to the lower left of the frame.

The image was taken on 2 November 2025, during Juice’s first slot for observing 3I/ATLAS. It was two days before Juice’s closest approach to the comet, which occurred on 4 November at a distance of about 66 million km.

Because Juice is presently behind the Sun (as seen from Earth), most of the data it collected during its closest approach won’t be downloaded until February. This one partial image is only a fore taste.

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The insane terrain inside Mars’ Death Valley

12:30 pm

taffy terrain
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on October 27, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The science team labels this a “twisted surface,” to which I think we all can agree. What we are looking at is a geological feature found only on Mars in only one region that has been labeled “taffy terrain” by scientists. 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.” Because of its weird nature I have posted many cool images of it in the past (see here, here, here, here, here, and here).

In the case of the image to the right, the red dot marks the peak of a small knob, with the green dot on the upper left the low point about 900 feet below. As you can see, the taffy has migrated into the depressions, as some flowing material would.
» Read more

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Ground-based telescope actually photographs an exoplanet

10:51 am

exoplanet imaged directly
Click for original movie.

Using a new instrument on the Subaru Telescope in Hawaii astronomers have not only discovered a massive exoplanet orbiting a star, they have been able to actually photograph the planet itself.

The arrow in the picture to the right shows that planet. That picture is a screen capture from a short movie complied from five observations taken over several months earlier this year, showing the planet as it orbited the star, the light of which is blocked out so as to not blind the camera. From the press release:

The newly discovered planet, HIP 54515 b, orbits a star 271 light-years away in the constellation Leo. With nearly 18 times Jupiter’s mass, it circles its star at about Neptune’s distance from our Sun. But the star and planet appear very close when seen from Earth; roughly the size that a baseball seen 100 km away would appear. The SCExAO system produced extremely sharp images allowing us to see the planet.

The astronomers also used this new instrument to image a brown dwarf star with a mass equivalent to sixty Jupiters about 169 light years away.

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Weird mottled terrain in the dry tropics of Mars

1:11 pm

Mottled ridges
Click for full image.

Cool image time! The picture to the right, cropped, reduced, and enhanced to post here, was taken on October 28, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Labeled by the science team as “mottled ridged terrain,” it shows a relatively flat area of scattered broken-up flat-topped ridges and knobs, following no clear pattern of formation.

In trying to research this, I could only find one paper [pdf] discussing this kind of mottled ridges that did a survey of similar features across a large region to the northwest. That paper could not determine what caused such features, but came up with hypothesis. From the abstract:

While it is not possible to determine the precise formation mechanism of these polygonal ridge networks from our new data, their formation can be assessed in terms of three possibly separate processes: (1) polygonal fracture formation, (2) fracture filling and (3) exhumation. We find that polygonal
fracture formation by impact cratering and/or desiccation of sedimentary host deposits is consistent with our results and previous spectral studies. Once the polygonal fractures have formed, fracture filling by clastic dikes and/or mineral precipitation from aqueous circulation is most consistent with our results. Exhumation, probably by aeolian processes that eroded much of these ancient Noachian terrains where the ridges are present caused the filled fractures to lie in relief as ridges today.

To put this in plain terms, the initial polygon-patterned cracks were formed by either an impact or the drying out of the surface (similar to the cracks seen on dried mud here on Earth). Both could have contributed. Then material welled up from below, either lava or mud, that hardened to fill the cracks. Later erosion by wind stripped away the surface, leaving behind these broken ridges.

As always, the location adds some very interesting context.
» Read more

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Sunspot update: Sunspot activity again crashes far below predictions

11:17 am

It is the start of another month, so it is time again to post my monthly update of the never-ending sunspot cycle on the Sun, using NOAA’s own monthly update of its graph of sunspot activity and annotating it with extra information to illustrate the larger scientific context.

The green dot on the graph below indicates the level of sunspot activity on the Sun’s Earth-facing hemisphere during the month of November. And once again, the Sun surprised us, producing far less sunspots than expected, based on the April 2025 prediction by NOAA’s panel of solar scientists (as indicated by the purple/magenta line).
» Read more

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New data from VLT uncovers numerous debris disks around stars

9:01 am

A sampling of debris disks
Click for original

Using a new instrument on the Very Large Telescope (VLT) in Chile, astronomers have compiled a catalog of 51 potential exoplanet solar systems, all with intriguing debris disks surround the stars with features suggesting the existence of asteroids and comets.

The image to the right shows a sampling of those systems. From the press release:

“To obtain this collection, we processed data from observations of 161 nearby young stars whose infrared emission strongly indicates the presence of a debris disk,” says Natalia Engler (ETH Zurich), the lead author of the study. “The resulting images show 51 debris disks with a variety of properties — some smaller, some larger, some seen from the side and some nearly face-on – and a considerable diversity of disk structures. Four of the disks had never been imaged before.”

Comparisons within a larger sample are crucial for discovering the systematics behind object properties. In this case, an analysis of the 51 debris disks and their stars confirmed several systematic trends: When a young star is more massive, its debris disk tends to have more mass as well. The same is true for debris disks where the majority of the material is located at a greater distance from the central star.

Arguably the most interesting feature of the SPHERE debris disks are the structures within the disks themselves. In many of the images, disks have a concentric ring- or band-like structure, with disk material predominantly found at specific distances from the central star. The distribution of small bodies in our own solar system has a similar structure, with small bodies concentrated in the asteroid belt (asteroids) and the Kuiper belt (comets).

The data from various telescopes both on the ground and in space is increasingly telling us that our solar system is not unique, and that the galaxy is filled with millions of similar systems, all in different states of formation. This hypothesis is further strengthened by the appearance of interstellar comet 3I/Atlas, which despite coming from outside our solar system is remarkably similar to the comets formed here.

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Astronomers detect another galaxy that shouldn’t be there, so soon after the Big Bang

11:38 am

A spiral galaxy too early in the universe
Click for original.

Using the Webb Space Telescopes astronomers have detected another galaxy that shouldn’t be there, so soon after the Big Bang.

The image to the right comes from figure 1 of the peer-reviewed paper. The galaxy’s two spiral arms form a backward “S” emanating out from the galaxy’s nucleus. From the press release:

Using JWST, researchers Rashi Jain and Yogesh Wadadekar spotted a galaxy remarkably similar to our own Milky Way. Yet this system formed when the cosmos was barely 1.5 billion years old—roughly a tenth of its present age. They named it Alaknanda, after the Himalayan river that is a twin headstream of the Ganga alongside the Mandakini—fittingly, the Hindi name for the Milky Way.

…It already has two sweeping spiral arms wrapped around a bright, rounded central region (the galaxy’s ‘bulge’), spanning about 30,000 light-years across. Even more impressively, it is annually churning out new stars, their combined mass roughly equivalent to 60 times the mass of our Sun. This rate is about 20 times that of the present-day Milky Way! About half of Alaknanda’s stars appear to have formed in only 200 million years—a blink in cosmic time.

This galaxy underlines the difficulty for cosmologists by much of Webb’s data of the early universe. Present theories of galaxy formation say it should take billions of years to form such a spiral galaxy, meaning it shouldn’t exist as yet so soon, only 1.5 billion years after the Big Bang.

Either the theories have to be revised substantially, or they are simply wrong entirely. Or we are missing or lacking in some fundamental information about the early universe that skews all our theories.

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Three new papers find sugars, “gum,” and lots of stardust in the samples brought back from the asteroid Bennu

10:24 am

Bennu
The asteroid Bennu

Three new papers published this week have found that the samples brought back by OSIRIS-REx from the asteroid Bennu contained some unexpected or unusual materials, including sugars that are important for biology, a gumlike material never seen before, and a much higher amount of stardust than expected.

The papers can be read here, here, and here.

As the press release notes, describing the sugar discovery:

The five-carbon sugar ribose and, for the first time in an extraterrestrial sample, six-carbon glucose were found. Although these sugars are not evidence of life, their detection, along with previous detections of amino acids, nucleobases, and carboxylic acids in Bennu samples, show building blocks of biological molecules were widespread throughout the solar system.

The stardust results found six-times the abundance previously found in other samples.

As for the “gum”, this was possibly the strangest discovery of all, coming from the solar system’s earliest time period.
» Read more

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