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Mathieu Lapôtre

@marslogander.bsky.social
217 followers 212 following 83 posts

Associate Prof @ Stanford, Planetary Geologist. I study planetary surface processes and what they can tell us about hydrology, climate, and habitability. 🏳️‍🌈 epsp.stanford.edu

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Reposted by Mathieu Lapôtre
Stanford Doerr School of Sustainability @stanforddoerr.bsky.social · 04/09/2026
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
stanford.io
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...
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Mathieu Lapôtre @marslogander.bsky.social · 16/06/2026
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
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Mathieu Lapôtre @marslogander.bsky.social · 18/12/2025
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)
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Reposted by Mathieu Lapôtre
The Geological Society of America (GSA) @geosociety.bsky.social · 01/11/2025
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
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Mathieu Lapôtre @marslogander.bsky.social · 16/10/2025
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
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Reposted by Mathieu Lapôtre
M. Colin Marvin @mcolinmarvin.bsky.social · 16/10/2025
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...
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Reposted by Mathieu Lapôtre
Stanford Doerr School of Sustainability @stanforddoerr.bsky.social · 29/09/2025
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
View from the back of a large room with a person presenting slides at the frontTwo people smiling holding lunar meteoritesA person presents their research during a poster sessionA speaker at a podium presents slides
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Reposted by Mathieu Lapôtre
Alexandra Delbot @alexandradelbot.bsky.social · 10/09/2025
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 ⬇️
radiofrance.fr
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...
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Reposted by Mathieu Lapôtre
Stanford Doerr School of Sustainability @stanforddoerr.bsky.social · 25/08/2025
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
stanford.io
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...
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Mathieu Lapôtre @marslogander.bsky.social · 22/08/2025
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
doi.org
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...
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Reposted by Mathieu Lapôtre
Carlos A. Alvarez @calvarez03.bsky.social · 02/06/2025
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
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Reposted by Mathieu Lapôtre
Carlos A. Alvarez @calvarez03.bsky.social · 02/06/2025
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...
nature.com
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...
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Mathieu Lapôtre @marslogander.bsky.social · 27/03/2025
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...
nature.com
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...
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Mathieu Lapôtre @marslogander.bsky.social · 05/03/2025
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
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Reposted by Mathieu Lapôtre
Jupiter Hansen (Cheng) @jupforjupiter.bsky.social · 03/02/2025
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-...
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Mathieu Lapôtre @marslogander.bsky.social · 10/12/2024
#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)
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Mathieu Lapôtre @marslogander.bsky.social · 13/12/2022
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)
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Mathieu Lapôtre @marslogander.bsky.social · 23/11/2022
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…
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Mathieu Lapôtre @marslogander.bsky.social · 17/08/2022
Congratulations to @mhasson7 for a brilliant qualifying exam!!! First PhD candidate from @StanfordEarth EPSP 🎉🥳 Time to celebrate with @Liorruba, @nilscp, @mcolinmarvin, and @b_amaro_!
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Mathieu Lapôtre @marslogander.bsky.social · 08/06/2022
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/…
jgs.lyellcollection.org
Mars as a time machine to Precambrian Earth | Journal of the Geological Society
As Mars transitioned from an early Earth-like state to the cold desert planet it is today, it preserved a near pristine record of surface environments in a world without plate tectonics and complex life. The records of Mars’ Earth-like surfaces have ...
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Mathieu Lapôtre @marslogander.bsky.social · 19/05/2022
Active saltation at Great Sand Dunes NP with @mcolinmarvin and @Liorruba! @GreatDunesNPS x.com/mcolinmarvin/s…
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Mathieu Lapôtre @marslogander.bsky.social · 12/05/2022
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…
doi.org
Accumulation of windblown sand in impact craters on Mars | Geology | GeoScienceWorld
Abstract. Loose sand, blown away from source regions by winds, is transported across Mars's surface into sand sheets and dunes and accumulates within
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Mathieu Lapôtre @marslogander.bsky.social · 26/04/2022
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/…
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Mathieu Lapôtre @marslogander.bsky.social · 21/04/2022
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…
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Mathieu Lapôtre @marslogander.bsky.social · 21/01/2022
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…
earth.stanford.edu
Sustainability Undergraduate Research in Geoscience and Engineering Program (SURGE)
Join us this summer for 8 weeks of fully funded mentored research and graduate school preparation. SURGE is a program for undergraduate students who are new to research and want to explore the field of sustainability in a community that celebrates inclusion. SURGE is funded in part by the National Science Foundation and the Stanford Doerr School of Sustainability.
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Mathieu Lapôtre @marslogander.bsky.social · 13/12/2021
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 😅
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Mathieu Lapôtre @marslogander.bsky.social · 18/08/2021
Don’t take all the credit @SarcasticRover, you were helped by hundreds of other government employees @NASA here on Earth! 😜 x.com/SarcasticRover…
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Mathieu Lapôtre @marslogander.bsky.social · 09/07/2021
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!
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Mathieu Lapôtre @marslogander.bsky.social · 20/06/2021
Back from a fun and productive week in the field with @mhasson7 and @_algunn!
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Mathieu Lapôtre @marslogander.bsky.social · 17/05/2021
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…
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Mathieu Lapôtre @marslogander.bsky.social · 30/04/2021
Wanna learn more about how to map surface winds on Mars from dunes using machine learning? Make sure to check out @Liorruba’s #vEGU21 invited presentation @ 9:05 am CEST/12:05 am PDT! Abstract:@EuroGeosciences @StanfordEarth meetingorganizer.copernicus.org/EGU21/EGU21-12…
meetingorganizer.copernicus.org
CO Meeting Organizer EGU21
The surface of Mars is riddled with dunes that form by accumulating sand particles that are carried by the wind. Since dune geometry and orientation adjust in response to prevailing wind conditions, the morphometrics of dunes can reveal information about the winds that formed them. Previous studies inferred the prevailing local wind direction from the orientation of dunes by manually analyzing spacecraft imagery. However, building a global map remained challenging, as manual detection of individual dunes over the entire Martian surface is impractical. Here, we employ Mask R-CNN, a state-of-the-art instance segmentation neural network, to detect and analyze isolated barchan dunes on a global scale.We prepared a training dataset by extracting Mars Context Camera (CTX) scenes of dune fields from a global CTX mosaic, as identified in the global dune-fields catalog. Images were cropped and standardized to a resolution of 832x832 pixels, and labeled using Labelbox’s online instance segmentation platform. Image augmentation and weight decay were employed to prevent overfitting during training. By inspecting 100 sample images from the validation database, we find that the network correctly identified ~86% of the isolated dunes, falsely identifying one feature as a barchan dune in a single image.
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Mathieu Lapôtre @marslogander.bsky.social · 29/04/2021
Up bright and early for #vEGU2021 session on bedform morphodynamics! Awesome presentations so far - many thanks to chairs @anne_baar, Suleyman Naqshband, @salesefra, and the other conveners! @EuroGeosciences
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Mathieu Lapôtre @marslogander.bsky.social · 18/03/2021
Tune in tomorrow morning at 9 am PDT / 12 pm EDT for LPSC’s session on surface-atmosphere interactions on icy worlds, featuring my very first work on Titan with @mike_malaska and @starsarecalling! #LPSC2021 #LPSCOceanWorlds @LPSCHaiku x.com/marslogander/s…
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Mathieu Lapôtre @marslogander.bsky.social · 11/03/2021
Way to go @mhasson7 for being one of this year’s NCALM seed proposal winners!@StanfordEarth @NCALM_UH @OpenTopography ncalm.cive.uh.edu/news/ncalm-ann…
ncalm.cive.uh.edu
NCALM Announces 2020 Seed Proposal Winners | NCALM
The National Center for Airborne Laser Mapping surveys multiple projects each year for graduate student PIs whose research would be enhanced by airborne lidar data. Students write and submit a two- to three-page proposal to be considered for an award (ncalm.cive.uh.edu/seed/about). The applications are reviewed by the NCALM Steering Committee, who select winners based on intellectual merit and broader impact.
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Mathieu Lapôtre @marslogander.bsky.social · 01/03/2021
These phone algorithms are really becoming quite good...
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Mathieu Lapôtre @marslogander.bsky.social · 24/02/2021
Many studies have followed up on our surprising observations in 2016 of large sand ripples on Mars that may help us decipher Mars’ atmospheric past from ancient sandstones. Check out our up-to-date summary of new findings and outstanding questions: agupubs.onlinelibrary.wiley.com/doi/full/10.10…
agupubs.onlinelibrary.wiley.com
An Evolving Understanding of Enigmatic Large Ripples on Mars
A new model predicts small windblown ripples should grow to be meter-scale on Mars That model cannot explain some observations that appear to be more consistent with an aerodynamic origin for lar...
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Mathieu Lapôtre @marslogander.bsky.social · 22/02/2021
🤯😍😭🤯🥰 x.com/NASAPersevere/…
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Mathieu Lapôtre @marslogander.bsky.social · 19/02/2021
Possibly the coolest thing I’ve ever seen... x.com/NASAPersevere/…
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Mathieu Lapôtre @marslogander.bsky.social · 12/01/2021
LPSC Abstract #1135 Sand grains on Titan Under wind or river flow Roll and rest. Not grow. cc: @mike_malaska @starsarecalling #LPSCHaiku #lpsc2021 @LPSCHaiku
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Mathieu Lapôtre @marslogander.bsky.social · 07/12/2020
Starting right now #AGU2020: EP005 - Meandering Flows: Patterns & Processes on Earth & Beyond I, chaired by @alvitello1 @zzsylvester @RiversToRocks
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Mathieu Lapôtre @marslogander.bsky.social · 06/12/2020
👌 x.com/_algunn/status…
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Mathieu Lapôtre @marslogander.bsky.social · 04/12/2020
Oh Pasadena... 😊
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Mathieu Lapôtre @marslogander.bsky.social · 25/11/2020
And we explore other planets too!! x.com/Stanford/statu…
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Mathieu Lapôtre @marslogander.bsky.social · 07/11/2020
A pretty accurate summary of the past few days, Sleeping Beauty edition! youtu.be/92gd8K_jX30
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Mathieu Lapôtre @marslogander.bsky.social · 22/10/2020
😍😍😍 x.com/OSIRISREx/stat…
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Mathieu Lapôtre @marslogander.bsky.social · 17/10/2020
Copy and paste a reply but change what the mars rover is scanning. ____ __ [ ._.•] |口\___Ⅱ"_╔•═•[(o) \╔╦╗_I╗ / \ _❍❍❍__❍______🦠____ x.com/abbyfrae/statu…
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Mathieu Lapôtre @marslogander.bsky.social · 30/06/2020
We won’t meet in person in Montréal, but the invitation to submit to our session still stands! x.com/marslogander/s…
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Mathieu Lapôtre @marslogander.bsky.social · 23/04/2020
Hot off the press @AguAdvances: “The Pace of Fluvial Meanders on Mars and Implications for the Western Delta Deposits of Jezero Crater”Couldn’t be more excited for your mission, @NASAPersevere! You got really cool stuff in store!! #Mars2020 #Jezero agupubs.onlinelibrary.wiley.com/doi/full/10.10…
agupubs.onlinelibrary.wiley.com
The Pace of Fluvial Meanders on Mars and Implications for the Western Delta Deposits of Jezero Crater
We develop a new model to infer the lateral migration rate of ancient meandering rivers on Mars from measurements of channel width Combined with Jezero-delta stratigraphy, our model suggests that t...
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Mathieu Lapôtre @marslogander.bsky.social · 19/03/2020
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Mathieu Lapôtre @marslogander.bsky.social · 02/03/2020
Probing Space to Understand Earth It was so much fun writing this one up with @GeoJGO @lavainspace @KirstenSiebach @ChrisCrossSci @smtikoo and Robin!Free link to pdf:@StanfordEarth @SESEASU @RiceEarthSci rdcu.be/b2otq nature.com/articles/s4301…
nature.com
Probing space to understand Earth
Nature Reviews Earth & Environment - Though lessons learned from Earth are frequently applied to other planets, there is much to learn about our own planet from the Solar System and beyond....
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