Tag: science

New data raises doubts about exoplanet having chemicals that on Earth come from life

1:02 pm

The uncertainty of science: Using new data from the Webb Space Telescope, scientists now conclude that the identification on an exoplanet in April 2025 of the molecules dimethyl sulfide (DMS) and/or dimethyl disulfide (DMDS) — both of which on Earth are only associated with the presence of life — is now uncertain and that these molecules likely aren’t there.

The new work uses [Webb] data to better qualify what is going on. The work confirms the presence of an ocean on this peculiar exoplanet, although it can’t confirm if there is a thick or thin atmosphere. They couldn’t find water vapor in the atmosphere, suggesting that there is an efficient cold trap, keeping evaporation to a minimum on this temperate sub-Neptune world.

Those potential biosignatures were all below the threshold for an undeniable detection, and their model suggests that a possible presence of DMS could be explained by sources unrelated to life. They advise considering more and different molecules to use as biosignatures. Astronomers are studying worlds that are very different from our own, and the chemical signatures that seem obvious here on Earth might not fit well with those exoplanets.

In other words, they simply don’t have enough data to know, one way or the other. No surprise, The science of studying exoplanets is in its infancy, and right now can only tease out the smallest of details based on our limited technology and the distances involved.

You can read the new paper here [pdf]. It notes further that using these molecules as a sign of life is also a mistake, as they can be created in other ways having nothing to do with biology.

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Curiosity looks back

10:12 am

Curiosity looks back
Click for original image.

Cool image time! The picture to the right, reduced and enhanced to post here, was taken on July 28, 2025 by the left navigation camera on the Mars rover Curiosity. It looks to the north, down the flanks of Mount Sharp and across the floor of Gale Crater to its mountainous rim about 30 miles way, seen on the horizon.

The view is so clear because of the season, as noted in the science team’s blog post today:

We’re still in the time of year where the atmosphere at Gale is reasonably dust-free (at least, compared to later in the year), allowing us to look all the way out to and beyond the Gale crater rim. The upper slopes of Mount Sharp have also re-emerged to our east after spending months hidden behind the walls of Gediz Vallis. There’s a bit more sand and dust in this location than we’ve seen recently, so we can also see the trail left behind by the rover’s wheels as we drove to this location

The ridge in the foreground is an example of the boxwork Curiosity is presently traversing. It is now on one of those ridges, and will be moving along it in short drives as the science team studies the geology here. The rover’s tracks leading up to this position can be seen clearly.
» Read more

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A Webb false color image of a planetary nebula

9:32 am

A Webb false color image of a planetary nebula
Click for original image.

Cool image time! The picture to the right, reduced and sharpened to post here, was released today by the science team of the Webb Space Telescope, showing the planetary nebula NGC 6072 in infrared false color.

This particular image was one of two taken by Webb, and looked at the nebula in the near infrared.

[I]t’s readily apparent that this nebula is multi-polar. This means there are several different elliptical outflows jetting out either way from the center, one from 11 o’clock to 5 o’clock, another from 1 o’clock to 7 o’clock, and possibly a third from 12 o’clock to 6 o’clock. The outflows may compress material as they go, resulting in a disk seen perpendicular to it. Astronomers say this is evidence that there are likely at least two stars at the center of this scene. Specifically, a companion star is interacting with an aging star that had already begun to shed some of its outer layers of gas and dust.

The central region of the planetary nebula glows from the hot stellar core, seen as a light blue hue in near-infrared light. The dark orange material, which is made up of gas and dust, follows pockets or open areas that appear dark blue. This clumpiness could be created when dense molecular clouds formed while being shielded from hot radiation from the central star. There could also be a time element at play. Over thousands of years, inner fast winds could be ploughing through the halo cast off from the main star when it first started to lose mass.

The second image, taken in the mid-infrared, shows expanding dust shells, with some forming an encircling ring around the central nebula.

It is believed that the two stars at the center of this nebula act to churn the expanding material to form this complex shape. Imagine them functioning almost like the blades in a blender.

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Thales Alenia ships the orbit insertion module for the Mars sample return mission

8:59 am

Though the entire project remains in limbo at NASA and might be cancelled, the European aerospace company Thales Alenia this week completed construction of the orbit insertion module for the Mars sample return mission that will place the orbiter — also built by European companies — in Mars orbit and will eventually bring the samples back to Earth.

On 28 July, Thales Alenia Space announced that the module had passed its test campaign with “excellent results.” According to the update, the company had packed and shipped the Orbit Insertion Module from its Turin facilities to Airbus in Stevenage a few days earlier. The delivery marks a key milestone in the development of the Mars Return Orbiter.

The broader Earth Return Orbiter project passed a key milestone in July 2024 with the completion of the Platform Critical Design Review. This review confirmed the performance, quality, and reliability of the mission’s systems. With its successful conclusion, Airbus advanced to full spacecraft development, including the integration and testing of its various components, among them the Orbit Insertion Module.

Under the project’s present very complex design, NASA is supposed to provide the ascent rocket and capsule to bring the samples to Europe’s return orbiter. At the moment it is unclear who will build this, or even if it will ever get built. Thus, Europe might be building a very expensive Mars orbiter with no clear mission.

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Firefly wins new NASA lunar lander contract, worth $176.7 million

8:52 am

NASA announced yesterday that it has awarded Firefly a $176.7 million contract to use the company’s Blue Ghost lunar lander to deliver two rovers and three other science instruments to the Moon’s south pole region.

Under the new CLPS task order, Firefly is tasked with delivering end-to-end payload services to the lunar surface, with a period of performance from Tuesday to March 29, 2030. The company’s lunar lander is targeted to land at the Moon’s South Pole region in 2029.

This is Firefly’s fifth task order award and fourth lunar mission through CLPS. Firefly’s first delivery successfully landed on the Moon’s near side in March 2025 with 10 NASA payloads. The company’s second mission, targeting a launch in 2026, includes a lunar orbit drop-off of a satellite combined with a delivery to the lunar surface on the far side. Firefly’s third lunar mission will target landing in the Gruithuisen Domes on the near side of the Moon in 2028, delivering six experiments to study that enigmatic lunar volcanic terrain.

One of the rovers is being built in partnership with Canada.

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Third star destroying part of expanding shells surrounding binary Wolf-Rayet stars

3:00 pm

Apep system.
From figure 3 of the paper.

Using the Webb Space Telescope, astronomers think they can now disentangle the strange spiral shape of the expanding dust shells caused by the colliding powerful winds flowing from a binary pair of giant aging Wolf-Rayet stars, dubbed the Apep system.

Apparently, a third smaller O-type star sits in the system, and is acting to block the winds and destroy the dust within them, carving out a large cavity in the spiral shells. The image to the right, produced by the Very Large Telescope in Chile, shows the spiral dust shells shaped by the strong solar winds flowing and colliding from the binary Wolf-Rayet stars (the bright dot in the center). The O-type star can be seen just above them. The yellow lines indicate the empty cone. Without the O star computer models had predicted a very bright shell north of the binary, and its non-existence in VLT images caused these further Webb observations.

From the paper’s [pdf] conclusion:

The JWST observations of Apep reveal luminous circumstellar dust that support[s] … our finding that the O supergiant ‘northern companion’ is dynamically associated with the binary WR stars in Apep; this is the first time that dust destruction has been observed by a tertiary star in a colliding wind nebula, and marks Apep as part of a rare class of triple colliding wind binaries.

The dust produced by Wolf-Rayet stars is thought to be a major component in seeding the formation of later stars, such as our own Sun. Finding that a third star in the system can destroy that dust suggests (as always) that this process can be far more complicated that first believed.

Hat tip to BtB’s stringer Jay.

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Galaxies without end

8:55 am

Galaxies without end
Click for original.

Cool image time! The picture to the right, reduced and enhanced to post here, was taken by the Hubble Space Telescope as part of a monitoring program studying the two supernovae that have occurred in this galaxy previously.

Hubble has turned its attention toward NGC 1309 several times; previous Hubble images of this galaxy were released in 2006 and 2014. Much of NGC 1309’s scientific interest derives from two supernovae, SN 2002fk in 2002 and SN 2012Z in 2012. SN 2002fk was a perfect example of a Type Ia supernova, which happens when the core of a dead star (a white dwarf) explodes.

SN 2012Z, on the other hand, was a bit of a renegade. It was classified as a Type Iax supernova: while its spectrum resembled that of a Type Ia supernova, the explosion wasn’t as bright as expected. Hubble observations showed that in this case, the supernova did not destroy the white dwarf completely, leaving behind a ‘zombie star’ that shone even brighter than it did before the explosion. Hubble observations of NGC 1309 taken across several years also made this the first time the white dwarf progenitor of a supernova has been identified in images taken before the explosion.

The image however carries a far more philosophic component. Except for the star near the top (identified by the four diffraction spikes), every single dot and smudge you see in this picture is a galaxy. NGC 1309 is about 100 million light years away, but behind it along its line of sight and at much greater distances are innumerable other galaxies, so many it is impossible to count them. And each is roughly comparable in size to our own Milky Way galaxy, containing billions of stars.

The scale of the universe is simply impossible to grasp, no matter how hard we might try.

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One of NASA’s two Tracers satellites just launched has an issue

10:17 am

During the commissioning phase shortly after their launch earlier this week, one of NASA’s two Tracers satellites designed to study the solar wind and its interaction with the Earth’s magnetic field has had an as yet unnamed issue.

During the commissioning process, the team made routine adjustments to the power subsystem on both vehicles. While the adjustments achieved the desired results on one satellite, the other satellite requires further investigation by the team. Commissioning operations are temporarily paused while the team analyzes the situation and determines the appropriate response.

Though the press release provides no other information, it appears the satellite is having a problem producing the power expected.

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Mars and its two moons seen in the infrared by Europa Clipper

10:37 am

Mars and its two moons
Click for original.

Cool image time! The infrared image to the right, cropped, reduced, and enhanced to post here, was taken by Europa Clipper on February 28, 2025 just before it flew past Mars on its way to Jupiter.

Deimos is in the upper left corner, while Phobos is close to Mars.

When the image was taken by the mission’s Europa Thermal Emission Imaging System (E-THEMIS), the spacecraft was about 560,000 miles (900,000 kilometers) from the Red Planet. The image is composed of 200 individual frames, part of a continuous scan of 1,100 frames taken roughly a second apart over a period of 20 minutes. Scientists are using the tiny, point-like images of the moons to check the camera’s focus.

As this is an infrared image (measuring heat), it shows Mars’ northern polar cap as the dark oval at the top of the planet. The bright (and thus warmer) oval to the lower left is the shield volcano Elysium Mons.

This data suggests Europa Clipper’s thermal instrument is working as intended, which is essential for observing the ice content (if any) on Europa once it enters Jupiter orbit in 2030.

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The journal Science retracts 15-year-old paper that proposed arsenic as basic element of life

10:15 am

The death of science: Though numerous later research had rejected the conclusions of a 2010 research paper that had suggested a bacteria found at Mono Lake in Californa was using arsenic instead of phosphorus in its DNA, the journal Science that published that paper has now retracted it.

In a blog post accompanying this week’s retraction notice, Science’s current Editor-in-Chief Holden Thorp and Valda Vinson, executive editor of the Science family of journals, emphasize there is no suggestion of foul play in the GFAJ-1 paper. Instead, pointing to subsequent commentary and research that suggest some of the paper’s findings stem from contamination, not arsenic use by bacteria, they write: “Science believes that the key conclusion of the paper is based on flawed data.”

Speaking with Science’s News team, which operates independently from its research arm, study co-author and Arizona State University geochemist Ariel Anbar says the team disputes that assessment and has already addressed the referenced criticisms. “We stand by the data,” he adds.

Anbar added this in this report at Nature:

By contrast, one of the paper’s authors, Ariel Anbar, a geochemist at Arizona State University in Tempe, says that there are no mistakes in the paper’s data. He says that the data could be interpreted in a number of ways, but “you don’t retract because of a dispute about data interpretation”. If that’s the standard you were to apply, he says, “you’d have to retract half the literature”.

This action underlines the decline in open-mindedness in the academic field. It did not suffice to simply demonstrate in later papers that the paper’s conclusions were questionable. It was necessary to cancel it entirely, to airbrush it from history.

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The glaciers on Mars are almost pure ice with only a thin cover of dust and debris

9:55 am

A map of glaciers on Mars
A map of glaciers on Mars.

According to new research, scientists now think that the glaciers on Mars are almost pure ice, protected from sublimation by a thin cover of dust and debris.

Work over the last 20 years has demonstrated that at least some of these glaciers are mostly pure ice with only a thin cover of rock and dust, but according to a new paper published in Icarus, glaciers all over the planet actually contain more than 80% water ice, a significant finding. Ultimately, this means that Mars’s glacial ice deposits are nearly pure across the globe, providing a clearer understanding of Mars’ climate history and a possible resource for future utilization.

The researchers analyzed mid-latitude glaciers at five different locations in both the north and south hemispheres, and found that at every location the data suggested almost pure ice.

The map to the right, from earlier research, shows the prevalence of near-surface ice once you get above 30 degrees latitude. From the poles to the mid-latitudes it appears there is an ice sheet or “ice table” just below the surface. In the mid-latitudes glaciers dominate, as this appears to be the region where that ice is beginning to dissipate. In the equatorial regions little or no near-surface ice has been detected, though there has been some evidence in some places of ice at deeper depths.

This data once again demonstrates that Mars is not a desert like the Sahara, as we once believed. Instead, it more resembles Antarctica, where there is ice everywhere that simply needs to be processed for use.

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Study identifies range of interference produced by Starlink satellites

8:58 am

In analyzing about 76 million radio images produced by the new Square Kilometer Array (SKA) in Australia scientists have found within them signals produced by SpaceX’s Starlink satellites.

PhD candidate and study lead Dylan Grigg said the team detected more than 112,000 radio emissions from 1806 Starlink satellites, making it the most comprehensive catalogue of satellite radio emissions at low frequencies to date. “Starlink is the most immediate and frequent source of potential interference for radio astronomy: it launched 477 satellites during this study’s four-month data collection period alone,” Mr Grigg said. “In some datasets, we found up to 30 per cent of our images showed interference from a Starlink satellite.”

Mr Grigg said the issue wasn’t just the number of satellites, but the strength of the signals and the frequencies they were visible at. “Some satellites were detected emitting in bands where no signals are supposed to be present at all, such as the 703 satellites we identified at 150.8 MHz, which is meant to be protected for radio astronomy,” Mr Grigg said. “Because they may come from components like onboard electronics and they’re not part of an intentional signal, astronomers can’t easily predict them or filter them out.”

The researchers were careful to note that SpaceX has been following all international regulations, and that these signals are not a violation of any law or regulation. Further, they emphasized that “Discussions we have had with SpaceX on the topic have been constructive.”

Because many other such constellations are now being launched — with several from China that normally does not negotiate these issues like SpaceX — the scientists want new international regulations imposed to protect their work.

More and more it seems astronomers should simply move their operations into space or the Moon, where such issues will not exist. Getting above the atmosphere and away from our modern technological society provides so many benefits for research the move should be a no-brainer. That it is now also much cheaper to do it (thanks to SpaceX) makes the move even more practical.

For some reason however the idea seems too difficult for many astronomers to fathom.

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