Isotopic Evidence for a Cold and Distant Origin of the Interstellar Object 3I/ATLAS
Martin Cordiner, Nathan X. Roth, Marco Micheli, Geronimo Villanueva, Davide Farnocchia, Steven Charnley, Nicolas Biver, Dominique Bockelee-Morvan, Dennis Bodewits, Colin Orion Chandler, Jacques Crovisier, Maria N. Drozdovskaya, Kenji Furuya, Michael S. P. Kelley, Stefanie Milam, John W. Noonan, Cyrielle Opitom, Megan E. Schwamb, Cristina A. Thomas
Comments: In Review at Nature; March 6th 2026
Interstellar objects provide the only directly observable samples of icy planetesimals formed around other stars, and can therefore provide insight into the diversity of physical and chemical conditions occurring during exoplanet formation. Here we 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 = (0.95 +- 0.06)%, which is more than an order of magnitude higher than in known comets, while its range of 12C/13C 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, early in the history of the Galaxy. When interpreted with respect to models for Galactic chemical evolution, the carbon isotopic composition implies that 3I/ATLAS accreted roughly 10-12 billion years ago, following an early period of intense star formation. 3I/ATLAS thus represents a preserved fragment of an ancient planetary system, and provides direct evidence for active ice chemistry and volatile-rich planetesimal formation in the young Milky Way.
Isotopic ratios observed in the coma of 3I/ATLAS compared with Galactic and Solar System observations for D/H.
Isotopic Evidence for a Cold and Distant Origin of the Interstellar Object 3I/ATLAS by @drcordiner.bsky.social et al. (feat. @javacitrus.bsky.social @megschwamb.bsky.social and @cathomas.bsky.social)
JWST measurements of deuterium! Lots of deuterium!
10.03.2026 20:17
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Email from Chris Reynolds to the AXIS Team. Subject is disappointing AXIS news. Text of e-mail reads: Dear AXIS Friends,
The AXIS team has received some very disappointing news – we have been informed by NASA HQ that AXIS is not eligible for selection and hence the Concept Study Report (CSR) will not be subjected to the full review process.
AXIS represents the scientific aspirations of a large international community. As a member of one of the AXIS science working groups, you deserve a candid explanation from the PI of what happened and why. That is the purpose of this note.
NASA’s decision was programmatic and not based on a review of the technology or science; the mission profile described in the submitted CSR was over the allowed budget and schedule. How was such a thing possible? In short, with NASA-GSFC as the AXIS managing center, the mission formulation process was critically compromised by the seismic shifts occurring in NASA and the Federal government. The AXIS study team was hit hard by three unprecedented challenges:
NASA’s Deferred Resignation Program (DRP) and the pressure at GSFC to resign/retire created a rapid and uncontrolled loss of over 20 personnel with key expertise during a critical mission formulation period, including the main GSFC Project Manager (Jimmy Marsh) and the X-ray mirror lead (Will Zhang) and many discipline engineers.
GSFC priorities rapidly realigned to the FY2026 President’s Budget Request (PBR) that eliminated the Probe program, further reducing the availability of GSFC engineering and mission formulation personnel (incl. cost analysts and schedulers) over the critical Summer and Fall months. Key work was halted for almost seven weeks when the core GSFC AXIS study team, dominated by NASA civil servants, was furloughed during the government shutdown. NASA HQ’s extension to the CSR submission deadline (from 18-Dec-2025 to 29-Jan-2026) was inadequate compensation for the disruption and lost time.
Taken together, these factors disrupted the basic grass-roots costing process (which requires extensive “reach back” to the discipline engineers to assess labor requirements) as well as the cost-design iteration process that is central to the formulation of a cost-capped and schedule-constrained mission. While the mission design was finalized in April, our initial grass-roots costing (which was ~10% over budget) could only be completed in September due to the lack of assigned resources. With the subsequent government shutdown and then “pens down” in early-December forced by the GSFC Executive Review process, there was no opportunity to work through the set of cost/schedule savings that had already been identified by the AXIS team.
Ultimately, the GSFC executive council gave AXIS leadership the choice of submitting a CSR with a non-compliant schedule and cost, or not submitting a CSR at all. We of course proceeded with the submission, including a narrative that we understood the path to a cost-compliant profile (that we would have discussed with the review panels during the Site Visit). NASA HQ has ruled this stance to be unacceptable.
It is important to stress that NASA’s programmatic decision was before any technical review had been conducted. The decision was NOT due to any concerns about AXIS technology. Indeed, the AXIS Phase A work had major successes with furthering
Indeed, the AXIS Phase A work had major successes with furthering the key technologies. GSFC’s Next Generation X-ray Optics (NGXO) team successfully demonstrated iridium-coated, stress-compensated mirror segments that meet AXIS baseline requirements (i.e. segment-level performance at sub-arcsecond level). NGXO also built the first AXIS demonstrator mirror module, learning critical lessons about mirror alignment, mounting and bonding. On the detector side, MIT quickly moved to fabricate AXIS-like CCDs and, working with our colleagues at Stanford, recently demonstrated that they achieve the required readout rate and spectral resolution.
Similarly, NASA’s decision was NOT a judgment of the importance of AXIS science. The AXIS science case was rated excellent in the Step 1 review, and it only became stronger during our Phase A study. The AXIS Community Science Book, which many of you contributed to, is an extremely powerful demonstration of the relevance and importance of high-resolution X-ray observations to all areas of astrophysics. The Science Book is one of the most important legacies of the AXIS Phase A study and, I believe, will help define future mission concepts for many years to come. I thank you all from the bottom of my heart for all of your work on this.
AXIS has been a long journey; we started under the leadership of Richard Mushotzky more than nine years ago. During that time, it’s been an enormous privilege to work with amazing people; the AXIS science team, the incredible/brilliant GSFC and Northrop Grumman engineers, and the wider astrophysics community. I am, quite frankly, livid that AXIS ultimately fell victim to the programmatic chaos of 2025. The astronomical community deserves better. I hope that NASA leadership, especially at GSFC and HQ, can have an honest discussion about how to better support and protect programs during extraordinary times.
For now, as a community, we must look forward. There is still one excellent mission under consideration for the Probe program, PRIMA, and we wish them a smooth and speedy path to selection and flight. In X-ray astronomy, the SMEX and MidEX programs represent concrete pathways for focused, high-impact missions, and the scientific case we built for AXIS provides a strong foundation for those concepts. The technologies we advanced in Step 1 and Phase A, particularly the NGXO mirror work and the MIT/Stanford detector demonstrations, can anchor the next generation of proposals. Most importantly, the AXIS Community Science Book, representing more than 500 scientists across, is a living document and a powerful signal to NASA leadership that this community is organized, serious, and not going anywhere. I encourage everyone to use it actively, as a resource for future concept development, for Astro2030 engagement, and for building the next mission that will deliver high angular resolution X-ray imaging to address the fundamental questions about black hole growth, galaxy evolution, and the hot universe that motivated AXIS from the beginning. This community built something remarkable over nine years and that doesn't end here.
Thank you again for your support of AXIS over these times.
Best
Chris and the AXIS leadership team
The @axisprobe.bsky.social team learned that the phase A concept study report of AXIS (the Advanced X-ray Imaging Satellite) will not be reviewed because the lost personnel at NASA Goddard and government shutdown impacted our schedule and budget. 🔭 Here is the PI's e-mail with the explanation.
09.03.2026 20:05
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The Milky Way arcs over and behind this view looking up at Rubin's shiny silver dome toward a starry night sky.
Alerts from NSF–DOE Rubin Observatory have been flowing for about a week...how many have there been?? 🚨
So far, Rubin has generated....drumroll please🥁
~1.7 million world-public alerts!
That's ~1.7 MILLION objects that changed in brightness or position in just seven nights 🤯
🔭🧪
04.03.2026 22:55
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A black and white still photo of a dozen or so of the main characters and others in the episode standing in a group on a sidewalk or driveway looking pensively straight ahead at something offscreen. The men are wearing casual shirts and pants, the women casual dresses. A dark colored station wagon is partially visible in the background at left.
Tonight in 1959, “The Twilight Zone” episode “The Monsters Are Due On Maple Street” (season 1, episode 22)—Rod Serling’s taut and unforgettable Cold War parable depicting the societal consequences of irrational fear and paranoia of communist infiltration—was broadcast for the first time on CBS.
04.03.2026 15:34
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Scientific American has updated the figure, now grouped into swimmers, fliers, walkers/runners, and vehicles. A person on a bicycle remains the most efficient way to travel, compared to all forms of biological locomotion and mechanical transport.
www.scientificamerican.com/article/a-hu...
04.03.2026 11:52
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Two images of a planetary nebula in space. The image to the left, labelled “Euclid & Hubble”, shows the whole nebula and its surroundings. A star in the very centre is surrounded by white bubbles and loops of gas, all shining with a powerful blue light. Farther away a broken ring of red and blue gas clouds surrounds the nebula. The background shows many stars and distant galaxies. A white box indicates the centre of the nebula and this region is the image to the right, labelled “Hubble”. It shows the multi-layered bubbles, pointed jets and circular shells of gas that make up the nebula, as well as the central star, in greater detail.
Wowowow - our @science.esa.int Hubble's picture of the month for March is the Cat's Eye Nebula, from combined images of #Hubble and #Euclid. Euclid's wide field and low surface brightness sensitivity brings out an external shell. Incredible image. esahubble.org/images/potm2... 🔭
04.03.2026 02:56
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![Gazing into deep this dusty maelstrom using near-infrared filters, Hubble reveals many stars and star-forming activities that might otherwise be obscured by dust. Strongly red spots indicate [Fe II] emission. There are only a few tiny splotches of those. Make of that what you will.
Data from the following proposal were used to create this image: Peering to the Heart of Massive Star Birth
Red: WFC3/IR F164N
Cyan: WFC3/IR F160W
Blue: WFC3/IR F110W
North is 45.51° counter-clockwise from up.](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:cz5uoq2emhdgxcnndqq5our4/bafkreifil5mu7znyn2agqvxoif5a6wm23mz6obqnqy7zrkzl7rdgddrwlu)
Gazing into deep this dusty maelstrom using near-infrared filters, Hubble reveals many stars and star-forming activities that might otherwise be obscured by dust. Strongly red spots indicate [Fe II] emission. There are only a few tiny splotches of those. Make of that what you will.
Data from the following proposal were used to create this image: Peering to the Heart of Massive Star Birth
Red: WFC3/IR F164N
Cyan: WFC3/IR F160W
Blue: WFC3/IR F110W
North is 45.51° counter-clockwise from up.
RAFGL 5180 - From Judy Schmidt (geckzilla.bsky.social) - https://flic.kr/p/2jcRWq8
03.03.2026 00:00
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i was hiking there 30 years ago and the disappearance of most of the glacier (compared to my memory) is really shocking.
01.03.2026 22:32
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Just a quick one this morning while I have nothing else to do.
HST_9473_06_ACS_HRC_F435W_sci
HST_9473_06_ACS_HRC_F555W_sci
HST_9473_06_ACS_HRC_F814W_sci
Super Star Cluster M82-F - From Judy Schmidt (geckzilla.bsky.social) - https://flic.kr/p/bUFygH
01.03.2026 08:00
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1317 Km Altitude
Orbit (Perijove) 34 - 7/6/2021
Credit:
© Nasa/JPL-Caltech/SwRI/MSSS/AndreaLuck
Data processed from Nasa's Juno
PRODUCT ID :
JNCE_2021158_34C00001_V02
Ganymede Flyby - Nasa’s Juno PJ 34 - From Andrea Luck (andrealuck.bsky.social) - https://flic.kr/p/2mUN9EP
24.02.2026 15:00
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Coffee-growing countries becoming too hot to cultivate beans, analysis finds
Five countries responsible for 75% of world’s coffee supply record average of 57 extra days of coffee-harming heat a year
Coffee-growing countries becoming too hot to cultivate beans, analysis finds.
Five countries responsible for 75% of world’s coffee supply record average of 57 extra days of coffee-harming heat a year www.theguardian.com/environment/...
23.02.2026 14:36
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An infographic from Our World in Data titled "Global land use for food production" uses a series of stacked horizontal bar charts to visualize the distribution of Earth's surface and the disproportionate land requirements of livestock. The first bar shows Earth's surface is 71% ocean and 29% land (141 million km²); the land surface is then broken down into 76% habitable land, 10% glaciers, and 14% barren land. Of the habitable land, 45% (48 million km²) is used for agriculture, while 38% is forests and 13% is shrubland. The agricultural land bar reveals a major disparity: 80% (38 million km²) is dedicated to livestock (meat, dairy, and textiles) including grazing land and cropland for feed, while only 16% is used for crops for direct human consumption and 4% for non-food crops. Finally, two smaller bars at the bottom contrast this land use with nutritional output, showing that while livestock uses 80% of agricultural land, it only provides 17% of global calories and 38% of global protein, whereas plant-based foods provide 83% of calories and 62% of protein.
80% of agricultural land is used for livestock (and textiles), yet this huge land use provides only 17% of our calories and 38% of our protein.
16% of the land used for crops provides 83% of our calories and 62% of our protein. It's past time we rethink what we eat.
19.02.2026 21:34
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A line curve showing number of awards for fiscal year 2026 compared to fiscal years 2021-2025 across NSF. The fiscal year 2026 curve lies well below curves for other fiscal years.
NSF Update
Funding curve overall. A little bit of progress in the past week, but only a little bit.
Now by Directorate...
1/11
13.02.2026 21:21
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In Kopenhagen gibt es die Vorschrift, dass alle wichtigen Radwege bei Schneefall bis spätestens 08:00 Uhr morgens geräumt sein müssen, damit die Menschen sicher mit dem Fahrrad zur Arbeit fahren können. So sieht dass dann aus❤️😀
09.02.2026 09:16
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I like being able to see if my JWST observations succeeded by checking bluesky. 🔭,
14.02.2026 15:58
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Mondays are better with an octopus squid 🦑💫
The octopus squid (Octopoteuthis deletron) is unusual among squids. Most squids have eight arms and two long tentacles, making a total of 10 appendages. As young Octopoteuthis mature, their two feeding tentacles are reabsorbed into their bodies.
02.02.2026 17:49
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America is falling behind in the global EV race – that’s going to cost the US auto industry
Electric vehicles are a fast-growing share of auto sales in many countries, and Chinese automakers are benefiting as the US industry pulls back.
EVs now represent more than 10% of new car sales in 39 countries, including Vietnam at 38% and Indonesia at 15%.
In the U.S., that figure is less than 10%.
The gap signals a competitive problem that goes far beyond climate – it's about who controls the future of automotive jobs. buff.ly/H5ETTBQ
03.02.2026 12:14
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I remember Challenger as well. But my mother as a girl survived concentration camps in Indonesia, while both her parents perished. That is a whole different type of trauma. Only as an adult I realized how that trauma permeated her entire life, and in some form, passed down to her children.
28.01.2026 11:56
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Dragonfly 😍 dragonfly.jhuapl.edu/Gallery/file...
27.01.2026 15:50
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U.S. government has lost more than 10,000 STEM Ph.D.s since Trump took office
A Science analysis reveals how many were fired, retired, or quit across 14 agencies
The US government lost more than 10,000 STEM PhDs last year, according to an analysis by Science of newly released OPM data, with 11 departures for every hire. And many OPM calls "voluntary" separations were probably pushed. www.science.org/content/arti...
27.01.2026 01:28
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If you need some extra distraction from *gestures broadly at everything,* Kilauea is here to help. The next eruptive episode, episode 41, looks to be kicking off right now! Fountains are starting to grow in height.
USGS LIVE stream here: www.youtube.com/watch?v=gXKu...
24.01.2026 21:20
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