#planetaryscience — Public Fediverse posts

#PPOD: A total solar eclipse is seen from San Millán de los Caballeros, Spain, Wednesday, Aug. 12, 2026. A total solar eclipse swept across parts of Greenland, Iceland, northern Russia, the Atlantic Ocean, Spain, and a small corner of Portugal. A partial eclipse was visible in parts of the U.S., most of Canada, much of Europe, and northwest Africa. Credit: NASA/Bill Ingalls

#planetaryscience #space #science

Stripping Mars’ Atmosphere

Mars was once a warmer, wetter place, swathed in a thick and protective atmosphere. Unlike Earth, Mars lacks a strong global magnetic field, which allows the solar wind to strip its atmosphere, but the exact mechanisms of that process have been unclear. But a new study has caught the process in action.

By combining simultaneous measurements from two spacecraft–NASA’s MAVEN and China’s Tianwen-1–the team was able to monitor the upstream solar wind conditions and the atmospheric ions escaping. They found that previously-observed “plasma clouds” in the Martian atmosphere result from a Kelvin-Helmholtz instability between the solar wind and Mars’ electric field. Within these clouds, the ion flux is ten to a hundred times greater than at steady-state conditions.

This mechanism directly couples ion escape from Mars’ atmosphere to the solar wind, and it’s likely that this process plays out for other unmagnetized planets as well. (Image credit: Mars – NASA, illustration – C. Zhang et al.; research credit: C. Zhang et al.; via Gizmodo)

A recent study demonstrates that a single, sub-catastrophic asteroid impact formed the distinctive south pole depression and smooth, dusty regolith layer on Mars's moon Deimos.
#PlanetaryScience #Astrophysics #ImpactPhysics #Astronomy #sflorg
https://www.sflorg.com/2026/08/ps08182601.html

The Planet That Refused to Follow the Crowd

https://skmohindroo5.wordpress.com/2026/08/18/the-planet-that-refused-to-follow-the-crowd/

The Planet That Refused to Follow the Crowd

https://sanjaymohindroo.wordpress.com/2026/08/18/the-planet-that-refused-to-follow-the-crowd/

By utilizing a combination of neutron and X-ray tomography, scientists have successfully identified macroscopic, hydrogen-rich regions within the ancient Martian meteorite NWA 7034, providing concrete evidence of early water-rock interactions on Mars.
#PlanetaryScience #Geology #Mineralogy #AnalyticalChemistry #sflorg
https://www.sflorg.com/2026/08/ps08162601.html

As Director of the Carl Sagan Center at the SETI Institute, Dr. Nathalie Cabrol leads more than 120 scientists and conducts research spanning astrobiology, planetary exploration, autonomous robotics, and the search for biosignatures on other worlds.

#PlanetaryScience #Space #Science #SETI #NotJustAliens

Jupiter radius (Planetary science 🪐)

The Jupiter radius or Jovian radius has a value of 71,492 km, or of 11.2 Earth radii. The Jupiter radius is a unit of length used in astronomy to describe the radii of large planets and certain exoplanets. It is also used in describing certain stars, in particular brown dwarfs. The planet Jupiter has the approximate shape of an oblate spheroid, w...

https://en.wikipedia.org/wiki/Jupiter_radius

#JupiterRadius #Radii #Jupiter #UnitsOfLength #PlanetaryScience

NASA Completes Astronaut-Deployed Science Instrument for Lunar Surface

https://web.brid.gy/r/https://science.nasa.gov/missions/artemis/nasa-completes-astronaut-deployed-science-instrument-for-lunar-surface/

@Umbertogaetani Their simulations suggest that #water rising through narrow dykes would freeze too quickly to supply the volumes needed for features such as chaos terrain, pits, domes or ridges. #Turbulence makes this worse by enhancing heat loss, supercooling the water, producing frazil ice, and clogging the dyke.

If correct, shallow liquid reservoirs on #Europa may form more by local in situ melting than by direct #ocean-to-surface exchange.

#PlanetaryScience #SpacePhysics #IcyMoons

RE: https://mastodon.uno/@Umbertogaetani/117077488353005365

🌖🌊 Interesting new #NatureAstronomy paper on #Europa’s #subsurface #ocean:

Ojha, Barik & Buffo argue that direct liquid-water transport from Europa’s deep ocean into shallow subsurface reservoirs may be much more limited than often assumed.

🌍 https://doi.org/10.1038/s41550-026-02918-2

Thanks @Umbertogaetani for sharing ✌️

#PlanetaryScience #SpacePhysics #IcyMoons #Astrobiology

Happy birthday to #mathematician, aeronautical #engineer, philanthropist and Cherokee ‘hidden figure’ of the space race: Mary Golda Ross (1908-2008).⁠
⁠
Great-great-granddaughter of Chief John Ross, who was forced to lead his people on the Trail of Tears, Ross attributed her success in math to the Cherokee tradition of encouraging equal education for boys and girls. 🧵1/

https://minouette.etsy.com/listing/634592877

#printmaking #sciart #womenInSTEM #Indigineer #SpaceRace #planetaryScience #linocut #mastoArt

Europlanet (Planetary science 🪐)

Europlanet is a network linking planetary scientists from across Europe. The aim of Europlanet is to promote collaboration and communication between partner institutions and to support missions to explore the Solar System. EuroPlaNet co-ordinates activities in Planetary Sciences in order to achieve a long-term integration of this discipline in Europe. In 2021, the...

https://en.wikipedia.org/wiki/Europlanet

#Europlanet #PlanetaryScience #AstronomyOrganizations

Salt and Dunes

Photographer Barbara Brown captured these striking aerial views in Namibia. Coastal dunes and saltworks feature in the photos from Walvis Bay, where wind, waves, evaporation, and humankind have shaped the landscape. The colorful and dendritic dune images come from Sossusvlei, where the ephemeral Tsauchab River ends in the Namib Desert. Recent flooding left its mark on the dry landscape. (Image credit: B. Brown/IAPOTY; via Colossal)

Recent analyses indicate that liquid nitrogen is actively or recently rising to the surface of Pluto's Sputnik Planitia, marking the first evidence of recent liquid flows on the dwarf planet. This phenomenon creates distinct surface features comparable to meltwater channels found on Earth's glaciers.
#PlanetaryScience #Astrophysics #Glaciology #sflorg
https://www.sflorg.com/2026/08/ps08052601.html

New paper from Lorenzo Cesario: "Characterizing the oxidation state of rocky exoplanets with the Large Interferometer for Exoplanets (LIFE)". 🔭 It's his third first-author paper, and he only finished his MSc this year.

Read the paper: https://arxiv.org/abs/2607.28121

The gases a rocky planet releases depend on how oxidised its mantle is. 🌋 That matters for biosignatures: you can't say a gas is unusual without knowing what a lifeless planet would produce. And you can't measure mantle chemistry from ten parsecs.

So we tested whether it can be measured indirectly. We simulated what LIFE would see for Earth-sized planets at 10 parsecs, for six mantle oxidation states spanning twelve orders of magnitude in oxygen fugacity, and ran a retrieval.

The six states can be told apart. Carbon dioxide dominates the oxidised cases, ammonia the reduced ones, and methane peaks in the middle: second plot, black bars are the true values. Reduced atmospheres are harder to retrieve, because their spectra are flatter. First plot: red the input model, blue the retrieval, grey the noise, reduced cases on top.

Accepted at Monthly Notices of the Royal Astronomical Society, with @timlichtenberg, Michiel Min, Lena Noack, Caroline Brachmann (@freieuniversitaet), Eleonora Alei, Sascha Quanz and the LIFE Collaboration.

It's a proof of concept: one star type, one orbit, no photochemistry or clouds. Adding those is next. 🌍

#Exoplanets #PlanetaryScience #Astronomy #Astrodon

A 113-million-year-old mass extinction event of marine planktic foraminifera was driven by severe ocean acidification caused by massive volcanic carbon dioxide emissions. Microscopic fossil evidence confirms that acidic surface waters dramatically reduced the ability of these organisms to build calcium carbonate shells.
#IsotopeGeochemistry #Paleoclimatology #EvolutionaryBiology #MarineBiology #EarthScience #PlanetaryScience #sflorg
https://www.sflorg.com/2026/07/es07302601.html

#PPOD: Amateur astronomer Joël Lapointe was using Google Maps to plan a camping vacation in 2024 when he came across a feature in Quebec's Côte-Nord region that reminded him of an impact crater. He reported the finding, and now field investigations have found geological evidence that this previously unknown feature is indeed a crater from an impact 390 million years ago.

#planetaryscience #space #science

Ice Giant or Magma Ocean World?

Uranus and Neptune–known as our system’s ice giants–are our least explored planets. Both have received exactly one flyby, from the Voyager 2 spacecraft. The data from those flybys remain our primary source of knowledge about each planet. The traditional model for each planet’s interior (dating back to before the flybys) consists of three layers: a rocky core; an icy mantle made up of water, ammonia, and methane; and a hydrogen/helium-rich atmosphere. That structure is one way to match the limited measurements we have from these planets, but, as today’s preprint study points out, it’s not the only way.

The authors suggest an alternative structure, in which a hydrogen-rich atmosphere overlays a supercritical magma ocean capable of dissolving hydrogen into heavier, metallic elements. Their suggestion is motivated by several factors. First, objects in the outer solar system–including Kuiper Belt objects–have less icy material than originally assumed, which suggests that Uranus and Neptune’s progenitors wouldn’t have been so ice-rich, either. Second, our understanding of how “rocky” materials respond at the temperatures and pressures found in these planet interiors has evolved. In particular, silicate, hydrogen, and iron are actually miscible at these conditions. That means that discrete sub-layers separated by material type are not as likely.

Using the magma ocean model, the team found compositions for both Uranus and Neptune that conformed well to our limited data about their gravitational and magnetic field properties. Time–and more data–will tell as to which interior model best describes these enigmatic giants. (Image credit: NASA; research credit: E. Young et al. (preprint); via Gizmodo)

Asteroid (44) Nysa is a massive, extraordinarily bright E-type asteroid located in the main belt between Mars and Jupiter that possesses a rare three-lobed structure and is accompanied by a newly discovered small moon.
#Astronomy #PlanetaryScience #Astrophysics #sflorg
https://www.sflorg.com/2026/07/astr07302601.html

Pre-solar stardust grains from ancient, extinct stars acted as nucleation sites, allowing the first solid materials in our solar system to crystallize from a hot gas.
#Geochemistry #Astrophysics #PlanetaryScience. #sflorg
https://www.sflorg.com/2026/07/ps07302601.html

Neptune's small inner moons and rings are the re-accreted, shattered debris of an ancient system of larger icy satellites that were destroyed during a catastrophic gravitational event.
#Astronomy #Astrophysics #PlanetaryScience #sflorg
https://www.sflorg.com/2026/07/ps07292601.html

New paper from Harrison Nicholls, a close collaborator of ours now at the Institute of Astronomy in Cambridge: "Constraining the lives and times of exoplanets through evolutionary Bayesian retrievals". 🔭

Read the paper: https://arxiv.org/abs/2607.25845

Typical retrieval techniques in exoplanet astronomy work out what a small planet is made of by fitting it as it is today, because the model must run thousands of times and so be cheap. That leaves ambiguity: a sub-Neptune's density fits a steam atmosphere over a small core as well as a hydrogen envelope over a dense one.

Harrison fits the whole life instead, magma ocean to now. 🌋 Each guess is a coupled interior-atmosphere run. Asynchronous Bayesian optimisation makes it affordable: each worker starts its next simulation the moment its last ends, never idling for the batch. 100 simulations per retrieval, hours on under 10 cores.

On a warm terrestrial that recovers the volatile inventory it formed with to within ~20%, plus mantle redox and core fraction. Sub-Neptunes stay hard: evolutionary retrievals are no panacea, says the paper. ⏳

Figures: the three test planets on the observed population; then pink is what a static fit allows, black the evolving fit, the ring the truth.

Proof of concept on synthetic planets, built into PROTEUS, submitted to The Astrophysical Journal. With @timlichtenberg, Ben Riegler, Robb Calder and Vincent Fortuin.

#Exoplanets #PlanetaryScience #Astronomy #Astrodon #MachineLearning

The Chicxulub asteroid impact generated a global, impermeable cloud of fine silicate dust that trapped immense thermal radiation, superheating the Earth's surface and triggering a mass extinction via planet-wide spontaneous combustion.
#PlanetaryScience #AtmosphericScience #Geophysics #Paleontology #sflorg
https://www.sflorg.com/2026/07/ps07282601.html

#PPOD: This composite photo released on July 17, 2026, shows the crescent of Mars growing as NASA’s Psyche spacecraft approached the planet for a gravity assist. Psyche flew by Mars on May 15, 2026, using the planet’s gravity to gain speed and slightly tilt its trajectory. The flyby also gave the team an opportunity to prep for the science they will be conducting when they reach the metal-rich asteroid Psyche in 2029. Credit: NASA/JPL-Caltech/ASU

#planetaryscience #space #science

#ICYMI: On this week's #SETILive, Simon and Pascal celebrated the 50th anniversary of NASA's Viking 1 lander touching down on #Mars, and they talked about the controversial Labeled Release experiment results and the possibility that we found life. Watch the full conversation: https://youtube.com/live/mQelZROEZeg

#space #science #planetaryscience

New paper led by Joe Williams, a PhD student at the University of Exeter, with our group as co-authors: "Planetesimal Formation Across the Stellar Mass Spectrum and its Influence on Exoplanet-Inherited Volatile Budgets". ❄️

Read the paper: https://arxiv.org/abs/2607.20271

JWST keeps finding bare rock where small planets orbit M dwarfs, and the usual suspect is the star stripping it away. This points earlier. Joe simulated clouds collapsing into discs across a range of masses, and around the lightest M dwarfs the building blocks come out dry before any planet exists.

It's a question of timing. ⏳ Those discs run fast: planetesimals form within 500,000 years, inside the 700,000-year half-life of aluminium-26, so they heat from within and dry out. By 2 Myr the pebbles have drifted off, so what the planetesimals hold is what the planets inherit. Rocky worlds there would be born volatile-poor, which could be part of why JWST finds so little air. Models of TRAPPIST-1c agree.

In the schematic, top: a disc from a 0.1 solar mass cloud, one batch, all grey, all dehydrated. Bottom: clouds of 0.3 and up, an early batch and a second later, water-rich blue beside dry grey, the mix argued to sit behind our own meteorite split. 🌍

Accepted in Monthly Notices of the Royal Astronomical Society. With Sebastiaan Krijt, Joanna Drążkowska (Max Planck Institute for Solar System Research) and @timlichtenberg.

#Exoplanets #PlanetaryScience #Astronomy #Astrodon #OpenScience