Planets that orbit very close to their stars are expected to be airless, but scientists have recently observed planets that defy this theory. How is this possible? Stanford researchers offer an explanation that could inform the search for life beyond our solar system. stanford.io/4ypg6qJ

Why some planets have theory-defying atmospheres

Stanford researchers have developed a model that explains how lava-covered worlds close to their stars can retain their atmospheres. The new theory could inform the search for life beyond our solar sy...

stanford.io

Congratulations to newly minted Dr. @mcolinmarvin.bsky.social and Dr. Michael Hasson! I feel so lucky to have had you both as my first PhD students. Can’t wait to witness your next discoveries! #geomorphology #sedimentology #graduates #PhD @stanforddoerr.bsky.social

Busy week for @stanforddoerr.bsky.social EPSP at #AGU25! Started with PhD student Vittorio Colicci looking for clues about #Archean environments through the deposits of some of Earth’s oldest #coastal #dune fields in South Africa (12/16 am, EP21E-1659)

Did you know sand grains record their transport history? New research in Geology shows zircon grains reveal their journey through microscopic abrasion “microtextures”—even in billion-year-old rocks! Read more: geosociety.co/4oHG2J6 #Geology #GSAPubs

Just out: PhD candidate @mcolinmarvin.bsky.social shows that like in quartz, #zircon grains preserve microscopic archives of their transport history. But unlike in quartz, those archives remain decipherable for billions of years, unlocking first 90% of #Earth ’s history @stanforddoerr.bsky.social

Did you know that sand records its transport history as it moves across Earth's surface? We developed a new tool to investigate billion-year-old rocks by looking at microscopic features on zircon sand grains. Check out our new paper in @geosociety.bsky.social to see how! doi.org/10.1130/G537...

Over 100 planetary scientists from around the Bay Area recently gathered at Stanford to connect and discuss their research. Highlights: 📸 Laura Schaefer and Michelle Hill

Jusqu’ici, les géologues pensaient que les plantes avaient fait naître les rivières en méandres - ces grands cours d'eau en forme de S. Une nouvelle étude montre qu’elles existaient déjà avant : la végétation a seulement modifié leur façon de bouger 🌱 Explications avec du GIF végétal ⬇️

La végétation a sculpté la forme des rivières

Jusqu’ici, les géologues pensaient que les plantes avaient fait naître les rivières en méandres - ces grands cours d'eau en forme de S. Une nouvelle étude montre qu’elles existaient déjà avant : la vé...

radiofrance.fr

Findings from a recent study could upend the conventional view of how rivers have shaped continents over time. It’s “a significant revision to our understanding of the history of the Earth,” said lead author Michael Hasson. @marslogander.bsky.social

The rise of plant life changed how rivers move, study shows

Research reveals that unvegetated meandering rivers can geologically masquerade as braided rivers, suggesting they were much more common in the first 90 percent of Earth’s history than previously thou...

stanford.io

Plants change how river bends move - paper by PhD student Michael Hasson out as First Release in #Science!! Paper: doi.org/10.1126/scie... Before #plants, #meanders did not grow laterally as much but translated downstream, making them look like braided rivers in rocks. @stanforddoerr.bsky.social

Vegetation changes the trajectory of river bends

A primary axiom in geoscience is that the evolution of plants drove global changes in river dynamics. Notably, the apparent sinuosity of rivers, derived from the variance of sediment accretion directi...

doi.org

Our results suggest that on Mars, values of the aerodynamic roughness length may reach up to 1 cm—up to two orders of magnitude larger than typically assumed. #NASA Ames, @stanforddoerr.bsky.social, @marslogander.bsky.social

Excited to share our latest publication in @natcomms.nature.com, where we analyze the aerodynamic roughness length over equilibrated rippled sand beds with active saltation under atmospheric pressures intermediate between those of Earth and Mars. www.nature.com/articles/s41...

Aerodynamic roughness of rippled beds under active saltation at Earth-to-Mars atmospheric pressures - Nature Communications

Low-pressure wind tunnel experiments suggest that the aerodynamic roughness length on Mars, over rippled beds and under active saltation, may be dominated by form drag, reaching values up to two order...

nature.com

Postdoc Carlos Alvarez shows that Mars’s large #aeolian #ripples are not impact ripples through low-pressure #wind tunnel experiments at #NASA Ames. Very excited about this one! @stanforddoerr.bsky.social www.nature.com/articles/s41...

Ripples formed in low-pressure wind tunnels suggest Mars’s large windblown ripples are not impact ripples - Nature Communications

Low-pressure wind tunnel experiments suggest that large sand ripples on Mars are drag ripples, not impact ripples. Windblown drag ripples constitute an untapped record of atmospheric evolution under t...

nature.com

New paper by PhD student @mcolinmarvin.bsky.social uses #patterns formed by #dunes to better understand sources, pathways, and sinks of #sand on #Titan. Spoiler: #Xanadu has outsized influence on #eolian sediments, and sand travels far!! @stanforddoerr.bsky.social

M. Colin Marvin@mcolinmarvin.bsky.social · 2y ago

Check out our paper in @agu.org where we provide evidence for a continuous transport pathway around Titan’s equatorial dune fields, only interrupted by the Xanadu region (with implications for the nature of Titan’s sand grains!) agupubs.onlinelibrary.wiley.com/doi/full/10....

I'm giving a talk at Stanford tomorrow! If you're around, come join us. I think Zoom is an option too—details here: events.stanford.edu/event/earth-...

#Rivers, #winds, #waves, and #impacts are all on the program for Stanford EPSP at #AGU24! Come along with us to explore #landscapes through #space (#Earth, #Moon, #Mars) and #time ( #Archean / #Hesperian to #future) All times EST. (1/10)

This afternoon, @stanforddoerr undergrad @b_amaro_ will present his findings applying boulder-detection #AI model to HiRISE imagery on #Mars, with implications for surface processes and evolution. P25A-64 (2/6)

Mars’ thin atmosphere makes large windblown sand ripples, like water shapes ripples on Earth’s riverbeds! New paper by @stanforddoerr postdoc @Liorruba, with colleagues R. Ewing @TAMUGeosciences, @LoriKFenton @SETIInstitute, and former postdoc @_algunn now @MonashUni x.com/NatureComms/st…

Congratulations to @mhasson7 for a brilliant qualifying exam!!! First PhD candidate from @StanfordEarth EPSP 🎉🥳 Time to celebrate with @Liorruba, @nilscp, @mcolinmarvin, and @b_amaro_!

A long time coming - “#Mars as a Time Machine to Precambrian Earth” - now open access in J. @GeolSoc! Was such a fun one to write with inspiring coauthors @KirstenSiebach @smtikoo + others not on Twitter. @StanfordEarth jgs.lyellcollection.org/content/early/…

Active saltation at Great Sand Dunes NP with @mcolinmarvin and @Liorruba! @GreatDunesNPS x.com/mcolinmarvin/s…

Just off the press: new paper by former @StanfordEarth postdoc @_algunn, now lecturer @MonashEAE analyzing spatial and temporal patterns in sand accumulation in impact craters on #Mars. Suggests enhanced sediment production in L. Noachian-E. Hesperian! doi.org/10.1130/G49936…

Loved working with @mike_malaska and @starsarecalling on my first #Titan paper! We propose that a global sedimentary cycle, driven by seasons, could explain the distribution of Titan’s landscapes. Model inspired by how ooids form on Earth (cc: @lizzy_t) @StanfordEarth @NASAJPL x.com/stanforddoerr/…

A really cool study led by Dave Rubin I’ve had a lot of fun participating in. We showed that Mars’ atmosphere had thinned (at least temporarily) before the last episode of subaqueous deposition in Gale crater! #Mars @MarsCuriosity @StanfordEarth x.com/jgrplanets/sta…

Undergrads interested in #planetary surface processes, impact cratering, and #MachineLearning are invited to apply to @StanfordEarth‘s SURGE summer program (deadline Feb 4)! Come work with us! A list of projects is available @🌔☄️🪨💻 earth.stanford.edu/dei/surge#gs.n…

Having LOTS of technical difficulties at #AGU21 this morning but that won’t stop us! Pic of @radjanirad being creative here to allow those on Zoom to see her slides 😅

Don’t take all the credit @SarcasticRover, you were helped by hundreds of other government employees @NASA here on Earth! 😜 x.com/SarcasticRover…

Wrapping up a week of #Mars analog fieldwork in 🇮🇸 with the incredible SAND-E team @TAMU @PurdueEAPS @StanfordEarth @MissionCtrlSS @NASA w/ Ryan Ewing, Liz Rampe, @ironywithab @MasonKashauna @MarionNach @mikethorpe_geo @bedford_candice @mhasson7 @rudolpa and many others!

Back from a fun and productive week in the field with @mhasson7 and @_algunn!

Congratulations to @mcolinmarvin, incoming PhD student at @StanfordEarth, for this accomplishment! Looking forward to working with you on extraterrestrial sedimentary processes! x.com/ASU/status/139…