Matthias M. M. Meier
@mmmmeier.bsky.social
Meteorites, Museums, Mars, Mountains and many more things. Meteoriticist, Noble Gaser, Space Nerd, Family Man. Director of Naturmuseum St. Gallen, Switzerland. Private account (en/de).
🇨🇭🇸🇪🇲🇫🇪🇺🇺🇦 orcid.org/0000-0002-7179-4173
🇨🇭🇸🇪🇲🇫🇪🇺🇺🇦 orcid.org/0000-0002-7179-4173
Reposted by Matthias M. M. Meier
Unhook ourselves from oil and gas and we unhook ourselves from dependency on dictators, autocrats and expansionist regimes all over the planet.
Renewables and other low-carbon energy sources are not just good climate sense. They are also good political sense.
Renewables and other low-carbon energy sources are not just good climate sense. They are also good political sense.
January 6, 2026 at 5:04 PM
Unhook ourselves from oil and gas and we unhook ourselves from dependency on dictators, autocrats and expansionist regimes all over the planet.
Renewables and other low-carbon energy sources are not just good climate sense. They are also good political sense.
Renewables and other low-carbon energy sources are not just good climate sense. They are also good political sense.
Since this story is making the rounds again: a reminder that the Chinguetti (mesosiderite) meteorite was analyzed for cosmogenic radionuclides and noble gases (by Welten et al. 2001), and everything in that analysis suggests it was once part of a ca. 1 m sized meteoroid that fell to Earth 18 ka ago.
January 2, 2026 at 12:52 PM
Since this story is making the rounds again: a reminder that the Chinguetti (mesosiderite) meteorite was analyzed for cosmogenic radionuclides and noble gases (by Welten et al. 2001), and everything in that analysis suggests it was once part of a ca. 1 m sized meteoroid that fell to Earth 18 ka ago.
Start of the new year. Just the northern slopes of an actively forming mountain range, ploughed by a fragment of an old continent drifting north, on a water-tripple-point planet with abundant indigenous life, orbiting a middle aged yellow dwarf near the corotation radius of its galaxy.
January 1, 2026 at 10:36 PM
Start of the new year. Just the northern slopes of an actively forming mountain range, ploughed by a fragment of an old continent drifting north, on a water-tripple-point planet with abundant indigenous life, orbiting a middle aged yellow dwarf near the corotation radius of its galaxy.
Reposted by Matthias M. M. Meier
What do we want? USE!
When do we want it? NOW!
Sign the petition for a United States of Europe:
actionnetwork.org/petitions/un...
When do we want it? NOW!
Sign the petition for a United States of Europe:
actionnetwork.org/petitions/un...
December 29, 2025 at 12:18 PM
What do we want? USE!
When do we want it? NOW!
Sign the petition for a United States of Europe:
actionnetwork.org/petitions/un...
When do we want it? NOW!
Sign the petition for a United States of Europe:
actionnetwork.org/petitions/un...
I like "Solirad"! I also like that its suggested abbreviation (So) looks simliar to the S_0_ that has historically been used for the "solar constant".
Christmas on the archive!
@ericmamajek.bsky.social leads a paper with his usual precision, asking us astronomers (especially exoplanet folks) to clean up their jargon.
Introducing the Solirad: the nominal average flux the Earth receives from the Sun = 1361 W/m^2
arxiv.org/abs/2512.20126
@ericmamajek.bsky.social leads a paper with his usual precision, asking us astronomers (especially exoplanet folks) to clean up their jargon.
Introducing the Solirad: the nominal average flux the Earth receives from the Sun = 1361 W/m^2
arxiv.org/abs/2512.20126
The Solirad (So) as a Convenient Unit for Quoting Astronomical Irradiances for Planetary Insolations and Exoplanetary Instellations
Measurements of physical parameters for stars and (exo)planets are often quoted in units normalized to the Sun and/or Earth. The nominal total solar irradiance, ${S}^{\rm N}_{\odot}$, while based on a...
arxiv.org
December 24, 2025 at 8:38 AM
I like "Solirad"! I also like that its suggested abbreviation (So) looks simliar to the S_0_ that has historically been used for the "solar constant".
Reposted by Matthias M. M. Meier
Shaping the future of research funding. 🧪
The @snsf.ch Swiss National Science Foundation is looking for new members for the Foundation Council. Application deadline: 30 January 2026.
www.snf.ch/en/Boii3zvoj...
The @snsf.ch Swiss National Science Foundation is looking for new members for the Foundation Council. Application deadline: 30 January 2026.
www.snf.ch/en/Boii3zvoj...
New Foundation Council members wanted
Help shape research funding! The SNSF is advertising mandates for the Foundation Council, its strategic governing body.
www.snf.ch
December 23, 2025 at 3:35 PM
Shaping the future of research funding. 🧪
The @snsf.ch Swiss National Science Foundation is looking for new members for the Foundation Council. Application deadline: 30 January 2026.
www.snf.ch/en/Boii3zvoj...
The @snsf.ch Swiss National Science Foundation is looking for new members for the Foundation Council. Application deadline: 30 January 2026.
www.snf.ch/en/Boii3zvoj...
Imagine what could be done at just one coffee a week...
December 21, 2025 at 4:04 PM
Imagine what could be done at just one coffee a week...
Reposted by Matthias M. M. Meier
In most cases, we don't have the technology to directly see newborn planets orbiting baby stars. But the Gaia space telescope is so sensitive that it can measure the stars being yanked back & forth by the gravity of the hidden objects around them.
Full paper at link. 🧪🔭
arxiv.org/abs/2512.00157
Full paper at link. 🧪🔭
arxiv.org/abs/2512.00157
December 18, 2025 at 7:58 PM
In most cases, we don't have the technology to directly see newborn planets orbiting baby stars. But the Gaia space telescope is so sensitive that it can measure the stars being yanked back & forth by the gravity of the hidden objects around them.
Full paper at link. 🧪🔭
arxiv.org/abs/2512.00157
Full paper at link. 🧪🔭
arxiv.org/abs/2512.00157
Mozilla has been sendung me (and probably everybody else) messages with "Why we are asking for donations" recently. Well, Mozilla, here's your answer "why I won't be sending any donations" in your direction. Stop pushing the AI bullshit and we can talk.
Mozilla has a new CEO and he just announced that Firefox will evolve into a modern AI browser. This is a good example of how management doesn’t understand its own user base and why they go out of their way to install Firefox on Windows, Android, iOS and other devices blog.mozilla.org/en/mozilla/l...
December 17, 2025 at 6:33 AM
Mozilla has been sendung me (and probably everybody else) messages with "Why we are asking for donations" recently. Well, Mozilla, here's your answer "why I won't be sending any donations" in your direction. Stop pushing the AI bullshit and we can talk.
Reposted by Matthias M. M. Meier
A new "crash clock" says Earth orbit is three days from disaster.
If all satellite lost the ability to maneuver (eg in a solar storm), it says collisions would be imminent.
Really interesting study this. Story by me in @newscientist.com
www.newscientist.com/article/2508...
If all satellite lost the ability to maneuver (eg in a solar storm), it says collisions would be imminent.
Really interesting study this. Story by me in @newscientist.com
www.newscientist.com/article/2508...
Crash clock says satellites in orbit are three days from disaster
Satellites in orbit would begin to collide in a matter of days if they lost manoeuvrability during a solar storm or other outage
www.newscientist.com
December 16, 2025 at 12:29 PM
A new "crash clock" says Earth orbit is three days from disaster.
If all satellite lost the ability to maneuver (eg in a solar storm), it says collisions would be imminent.
Really interesting study this. Story by me in @newscientist.com
www.newscientist.com/article/2508...
If all satellite lost the ability to maneuver (eg in a solar storm), it says collisions would be imminent.
Really interesting study this. Story by me in @newscientist.com
www.newscientist.com/article/2508...
Reposted by Matthias M. M. Meier
Today in "Don't Trust AI to Tell You Facts": How several different "AI" programs messed up the simple fact of to whom I dedicated a book, and what that means for how much you should trust "AI" to tell you the truth about things (spoiler: not much at all):
whatever.scalzi.com/2025/12/13/a...
whatever.scalzi.com/2025/12/13/a...
“AI”: A Dedicated Fact-Failing Machine, or, Yet Another Reason Not to Trust It For Anything
I search my name on a regular basis, not only because I am an ego monster (although I try not to pretend that I’m not) but because it’s a good way for me to find reviews, end-of-the-yea…
whatever.scalzi.com
December 13, 2025 at 5:42 PM
Today in "Don't Trust AI to Tell You Facts": How several different "AI" programs messed up the simple fact of to whom I dedicated a book, and what that means for how much you should trust "AI" to tell you the truth about things (spoiler: not much at all):
whatever.scalzi.com/2025/12/13/a...
whatever.scalzi.com/2025/12/13/a...
Last Tuesday, I went to the hospital with a dinosaur to get an MRI... Working in a natural history museum allows you to say the weirdest things! ☺️🦕🏛️
December 12, 2025 at 3:19 PM
Last Tuesday, I went to the hospital with a dinosaur to get an MRI... Working in a natural history museum allows you to say the weirdest things! ☺️🦕🏛️
That is an interesting idea: if the solar system's initial 26Al inventory was produced by cosmic-rays (from a ~1 pc supernova (SN); as opposed to being actual SN debris), you'd expect cosmic-ray effects in other elements too (e.g., Ne - and we see that, occasionally!), and perhaps a conc. gradient?
Cosmic-Ray Bath in a Past Supernova Gives Birth to Earth-Like Planets
A key question in astronomy is how ubiquitous Earth-like rocky planets are. The formation of terrestrial planets in our solar system was strongly influenced by the radioactive decay heat of short-live...
arxiv.org
December 11, 2025 at 6:51 AM
That is an interesting idea: if the solar system's initial 26Al inventory was produced by cosmic-rays (from a ~1 pc supernova (SN); as opposed to being actual SN debris), you'd expect cosmic-ray effects in other elements too (e.g., Ne - and we see that, occasionally!), and perhaps a conc. gradient?
Reposted by Matthias M. M. Meier
🌌Il y a 19 ans, Hubble capturait cette image de l'amas d'étoiles Pismis 24 et de la nébuleuse NGC 6357. Ils sont situés à 8000 années-lumière de la Terre. Depuis, le JWST a, lui aussi, tourné son immense miroir vers cette partie du ciel.
📷ESA / NASA
📷ESA / NASA
December 11, 2025 at 6:02 AM
🌌Il y a 19 ans, Hubble capturait cette image de l'amas d'étoiles Pismis 24 et de la nébuleuse NGC 6357. Ils sont situés à 8000 années-lumière de la Terre. Depuis, le JWST a, lui aussi, tourné son immense miroir vers cette partie du ciel.
📷ESA / NASA
📷ESA / NASA
Reposted by Matthias M. M. Meier
Morf and Helled, open source
December 10, 2025 at 8:08 PM
Morf and Helled, open source
Reposted by Matthias M. M. Meier
The historic raise for Science agreed at #CM25 secures the Programme € 3787 million for the next five years.
Discover what we're planning to do with this increased budget, which is equivalent to about € 1.70 per European citizen per year 👉 www.esa.int/Science_Expl...
🔭 🧪
@cmundell.esa.int
Discover what we're planning to do with this increased budget, which is equivalent to about € 1.70 per European citizen per year 👉 www.esa.int/Science_Expl...
🔭 🧪
@cmundell.esa.int
December 10, 2025 at 10:25 AM
The historic raise for Science agreed at #CM25 secures the Programme € 3787 million for the next five years.
Discover what we're planning to do with this increased budget, which is equivalent to about € 1.70 per European citizen per year 👉 www.esa.int/Science_Expl...
🔭 🧪
@cmundell.esa.int
Discover what we're planning to do with this increased budget, which is equivalent to about € 1.70 per European citizen per year 👉 www.esa.int/Science_Expl...
🔭 🧪
@cmundell.esa.int
Reposted by Matthias M. M. Meier
My answers in English in an interview for a German newspaper (online version will be published a little later):
- I think Trump's initiative demonstrates the absolute inadequacy of his administration's expertise on modern Russia: they fundamentally don't understand what they're dealing with.
1/8
- I think Trump's initiative demonstrates the absolute inadequacy of his administration's expertise on modern Russia: they fundamentally don't understand what they're dealing with.
1/8
December 4, 2025 at 12:54 PM
My answers in English in an interview for a German newspaper (online version will be published a little later):
- I think Trump's initiative demonstrates the absolute inadequacy of his administration's expertise on modern Russia: they fundamentally don't understand what they're dealing with.
1/8
- I think Trump's initiative demonstrates the absolute inadequacy of his administration's expertise on modern Russia: they fundamentally don't understand what they're dealing with.
1/8
In case someone forgot. "Territorial integrity" including, explicitly, Crimea.
OTD in 1994 Russia signed the Budapest memo, guaranteeing Ukraine's territorial integrity in exchange for their nukes, 44 Ukrainian Tu-22 heavy bombers and 1,068 Kh-55 cruise missiles.
Which have been fired at Ukraine in this war.
Which have been fired at Ukraine in this war.
December 5, 2025 at 7:35 AM
In case someone forgot. "Territorial integrity" including, explicitly, Crimea.
When I was a post-doc at Lund University, we submitted a project to search sediments for grains from Beta Pictoris. Assuming they had the same content of radioactive Manganese-53 as early solar system materials, we wanted to find them by combining sophisticated decay counting and NanoSIMS. But...
I find this thought fascinating: Greg & Wiegert (arxiv) determine the fluxes of material from nearby debris disks, e.g. Beta Pictoris and Ran (+ 18 others). Unlike for solar system meteoroids/meteorites, the origin of such bodies would always be knowable from their dynamics. Just need to catch them!
A Catalogue of Interstellar Material Delivery From Nearby Debris Disks
We modeled the trajectories of material ejected from 20 nearby debris disk stars, including Epsilon Eridani (Ran), Vega, Fomalhaut, and Beta Pictoris, within a simulated Milky Way potential in order t...
arxiv.org
December 4, 2025 at 4:48 PM
When I was a post-doc at Lund University, we submitted a project to search sediments for grains from Beta Pictoris. Assuming they had the same content of radioactive Manganese-53 as early solar system materials, we wanted to find them by combining sophisticated decay counting and NanoSIMS. But...
Who had that on their 2025 bingo card?
December 4, 2025 at 4:21 PM
Who had that on their 2025 bingo card?
Reposted by Matthias M. M. Meier
You requested it, now it’s here - introducing Proton Sheets! The privacy-first alternative to Excel and Google Sheets.
Spreadsheets form the framework of modern businesses, and with Proton Sheets, you can ensure your data is private and secure.
1/4
Spreadsheets form the framework of modern businesses, and with Proton Sheets, you can ensure your data is private and secure.
1/4
December 4, 2025 at 12:30 PM
You requested it, now it’s here - introducing Proton Sheets! The privacy-first alternative to Excel and Google Sheets.
Spreadsheets form the framework of modern businesses, and with Proton Sheets, you can ensure your data is private and secure.
1/4
Spreadsheets form the framework of modern businesses, and with Proton Sheets, you can ensure your data is private and secure.
1/4
Reposted by Matthias M. M. Meier
By 2040, ~40% of the images from Hubble Space Telescope, and more than 96% from new and future space telescopes like SPHEREx, ARRAKIHS, and Xuntian will be contaminated by internet satellite constellations.
Read our new NASA article in Nature:
nature.com/articles/s4158…
Read our new NASA article in Nature:
nature.com/articles/s4158…
December 3, 2025 at 6:55 PM
By 2040, ~40% of the images from Hubble Space Telescope, and more than 96% from new and future space telescopes like SPHEREx, ARRAKIHS, and Xuntian will be contaminated by internet satellite constellations.
Read our new NASA article in Nature:
nature.com/articles/s4158…
Read our new NASA article in Nature:
nature.com/articles/s4158…
I find this thought fascinating: Greg & Wiegert (arxiv) determine the fluxes of material from nearby debris disks, e.g. Beta Pictoris and Ran (+ 18 others). Unlike for solar system meteoroids/meteorites, the origin of such bodies would always be knowable from their dynamics. Just need to catch them!
A Catalogue of Interstellar Material Delivery From Nearby Debris Disks
We modeled the trajectories of material ejected from 20 nearby debris disk stars, including Epsilon Eridani (Ran), Vega, Fomalhaut, and Beta Pictoris, within a simulated Milky Way potential in order t...
arxiv.org
December 4, 2025 at 6:58 AM
I find this thought fascinating: Greg & Wiegert (arxiv) determine the fluxes of material from nearby debris disks, e.g. Beta Pictoris and Ran (+ 18 others). Unlike for solar system meteoroids/meteorites, the origin of such bodies would always be knowable from their dynamics. Just need to catch them!
This is cool, even if it is tentative. Ground support for the "progressive disruption and re-accretion of martian moons" hypothesis. This hypothesis alleviates the strange coincidence that we would live so close (~30-50 Ma) to the end of Phobos' lifetime - not a problem if it's just a cycle.
More evidence that Mars has a colorful history. In the past, the Red Planet probably had rings at certain times, and a larger moon (or moons) at others.
In the future, Mars will probably have rings again. 🧪🔭
eos.org/articles/sed...
In the future, Mars will probably have rings again. 🧪🔭
eos.org/articles/sed...
December 2, 2025 at 7:56 PM
This is cool, even if it is tentative. Ground support for the "progressive disruption and re-accretion of martian moons" hypothesis. This hypothesis alleviates the strange coincidence that we would live so close (~30-50 Ma) to the end of Phobos' lifetime - not a problem if it's just a cycle.
The natural state of capitalism is "trickle-up". The only way to counter the "trickle-up" is taxes.
CEO-to-worker pay ratio in 1965: 20-1
CEO-to-worker pay ratio in 1990: 75-1
CEO-to-worker pay ratio today: 280-to-1
Trickle-down economics was always a sham.
Nothing has ever trickled down.
CEO-to-worker pay ratio in 1990: 75-1
CEO-to-worker pay ratio today: 280-to-1
Trickle-down economics was always a sham.
Nothing has ever trickled down.
December 1, 2025 at 7:21 AM
The natural state of capitalism is "trickle-up". The only way to counter the "trickle-up" is taxes.