Mark Marley
@markmarley.bsky.social
Personal account. Substellar science since the 80s.
Reposted by Mark Marley
HiRISE Image of Exocomet 3I/ATLAS!
On 2 October 2025, MRO turned away from Mars to image 3I/ATLAS, only the third interstellar object ever observed passing through our solar system!
https://www.uahirise.org/releases/3i-atlas/
On 2 October 2025, MRO turned away from Mars to image 3I/ATLAS, only the third interstellar object ever observed passing through our solar system!
https://www.uahirise.org/releases/3i-atlas/
November 19, 2025 at 9:01 PM
HiRISE Image of Exocomet 3I/ATLAS!
On 2 October 2025, MRO turned away from Mars to image 3I/ATLAS, only the third interstellar object ever observed passing through our solar system!
https://www.uahirise.org/releases/3i-atlas/
On 2 October 2025, MRO turned away from Mars to image 3I/ATLAS, only the third interstellar object ever observed passing through our solar system!
https://www.uahirise.org/releases/3i-atlas/
LPL’s Shane Byrne speaking truth:
“Byrne was less diplomatic. 'It's a bunch of nonsense,' he said, with nothing more to add.”
arizonadailystar-az.newsmemory.com?publink=33a9...
“Byrne was less diplomatic. 'It's a bunch of nonsense,' he said, with nothing more to add.”
arizonadailystar-az.newsmemory.com?publink=33a9...
UA team catches rare interstellar comet on camera
HENRY BREANArizona Daily Star A University of Arizona-led team using a
arizonadailystar-az.newsmemory.com
November 22, 2025 at 4:05 PM
LPL’s Shane Byrne speaking truth:
“Byrne was less diplomatic. 'It's a bunch of nonsense,' he said, with nothing more to add.”
arizonadailystar-az.newsmemory.com?publink=33a9...
“Byrne was less diplomatic. 'It's a bunch of nonsense,' he said, with nothing more to add.”
arizonadailystar-az.newsmemory.com?publink=33a9...
Reposted by Mark Marley
And the camera and the spacecraft were designed to be pointed at Mars 300 km below us, not out at an interstellar comet 30 million km away!
November 19, 2025 at 9:59 PM
And the camera and the spacecraft were designed to be pointed at Mars 300 km below us, not out at an interstellar comet 30 million km away!
Reposted by Mark Marley
Here’s an annotated version of our comet image.
We also want to thank our downlink and uplink teams who spent a huge amount of time working on this. Our camera was not designed to image interstellar objects 19 million miles away, but their hard work and planning paid off.
We also want to thank our downlink and uplink teams who spent a huge amount of time working on this. Our camera was not designed to image interstellar objects 19 million miles away, but their hard work and planning paid off.
November 19, 2025 at 9:31 PM
Here’s an annotated version of our comet image.
We also want to thank our downlink and uplink teams who spent a huge amount of time working on this. Our camera was not designed to image interstellar objects 19 million miles away, but their hard work and planning paid off.
We also want to thank our downlink and uplink teams who spent a huge amount of time working on this. Our camera was not designed to image interstellar objects 19 million miles away, but their hard work and planning paid off.
Lots of people thought of doing this, including me back on the day the comet was announced. Crazy fun to see the image now.
November 19, 2025 at 9:22 PM
Lots of people thought of doing this, including me back on the day the comet was announced. Crazy fun to see the image now.
Reposted by Mark Marley
Congratulations to the LPL's HiRISE team for successfully imaging interstellar comet 3I/ATLAS!
HiRISE Image of Exocomet 3I/ATLAS!
On 2 October 2025, MRO turned away from Mars to image 3I/ATLAS, only the third interstellar object ever observed passing through our solar system!
https://www.uahirise.org/releases/3i-atlas/
On 2 October 2025, MRO turned away from Mars to image 3I/ATLAS, only the third interstellar object ever observed passing through our solar system!
https://www.uahirise.org/releases/3i-atlas/
November 19, 2025 at 9:14 PM
Congratulations to the LPL's HiRISE team for successfully imaging interstellar comet 3I/ATLAS!
Amazing job by the HiRISE team @uahirise.bsky.social to target and image this object.
November 19, 2025 at 8:31 PM
Amazing job by the HiRISE team @uahirise.bsky.social to target and image this object.
Reposted by Mark Marley
NASA's pix of the interstellar comet 3I/ATLAS are now up science.nasa.gov/solar-system...
This is the HiRISE/MRO image ⬇️
This is the HiRISE/MRO image ⬇️
November 19, 2025 at 8:27 PM
NASA's pix of the interstellar comet 3I/ATLAS are now up science.nasa.gov/solar-system...
This is the HiRISE/MRO image ⬇️
This is the HiRISE/MRO image ⬇️
Reposted by Mark Marley
Our image should come online at uahirise.org very shortly.
HiRISE | High Resolution Imaging Science Experiment
uahirise.org
November 19, 2025 at 8:09 PM
Our image should come online at uahirise.org very shortly.
Reposted by Mark Marley
NASA Shares Interstellar Comet 3I/ATLAS Images
YouTube video by NASA
www.youtube.com
November 19, 2025 at 8:01 PM
Reposted by Mark Marley
🧪🔭⭐ #exoplanets #exoplanet #youngplanets
New paper from our group and @madysonbarber.bsky.social today!
We report a brand-new planet around a <50 Myr star—adding to a very small (but rapidly growing!) population of the youngest known transiting planets.
Paper: arxiv.org/pdf/2511.10734
New paper from our group and @madysonbarber.bsky.social today!
We report a brand-new planet around a <50 Myr star—adding to a very small (but rapidly growing!) population of the youngest known transiting planets.
Paper: arxiv.org/pdf/2511.10734
arxiv.org
November 19, 2025 at 2:43 PM
🧪🔭⭐ #exoplanets #exoplanet #youngplanets
New paper from our group and @madysonbarber.bsky.social today!
We report a brand-new planet around a <50 Myr star—adding to a very small (but rapidly growing!) population of the youngest known transiting planets.
Paper: arxiv.org/pdf/2511.10734
New paper from our group and @madysonbarber.bsky.social today!
We report a brand-new planet around a <50 Myr star—adding to a very small (but rapidly growing!) population of the youngest known transiting planets.
Paper: arxiv.org/pdf/2511.10734
A couple of weeks ago I started preparing today's Exoplanet grad class on atmospheric escape and thought, "why am I doing this when the world expert on atmospheric escape is Zahnle?". He kindly said yes to the ask, so I'm excited Kevin will be giving a remote lecture to my class today.
November 18, 2025 at 4:24 PM
A couple of weeks ago I started preparing today's Exoplanet grad class on atmospheric escape and thought, "why am I doing this when the world expert on atmospheric escape is Zahnle?". He kindly said yes to the ask, so I'm excited Kevin will be giving a remote lecture to my class today.
"Huge if True" podcast visited Mt. Lemmon and the Catalina Sky Survey @catalinaskysurvey.bsky.social
youtu.be/LOn-mmezykQ?...
youtu.be/LOn-mmezykQ?...
Humanity’s Real Plan to Stop This Asteroid (Feat. Mark Rober)
YouTube video by Cleo Abram
youtu.be
November 17, 2025 at 11:28 PM
"Huge if True" podcast visited Mt. Lemmon and the Catalina Sky Survey @catalinaskysurvey.bsky.social
youtu.be/LOn-mmezykQ?...
youtu.be/LOn-mmezykQ?...
We need a reimagined LPSC flavored meeting and the locale should be Tucson in March, after the gem show. Plenty of hotel choices along the free tram line that goes to the convention center. Visit Tucson is onboard to support this. If anyone has the bandwidth to invent the meeting we've got the city.
Abstracts submitted to LPSC 2026 are required to comply with White House (non-legally binding) executive orders forbidding mention of topics related to diversity, equity, and inclusion.
At least USRA/LPI isn't hiding it.
But is this what our community wants? Or deserves? I don't think so.
At least USRA/LPI isn't hiding it.
But is this what our community wants? Or deserves? I don't think so.
November 17, 2025 at 11:07 PM
We need a reimagined LPSC flavored meeting and the locale should be Tucson in March, after the gem show. Plenty of hotel choices along the free tram line that goes to the convention center. Visit Tucson is onboard to support this. If anyone has the bandwidth to invent the meeting we've got the city.
Great postdoc opportunity at LPL w/Sukrit Ranjan on exoplanet atmospheres including "hydrodynamic atmos. escape from rocky exoplanets, N & S cycling on early Mars & Earth, chem kinetics of early Earth, Venus, Mars...& interior-atmosphere interactions on rocky worlds" arizona.csod.com/ux/ats/caree...
Postdoctoral Research Associate I (Lunar and Planetary Laboratory)
The successful applicant will conduct original research in collaboration with Prof. Sukrit
Ranjan and his group related to the composition and structu...
arizona.csod.com
November 17, 2025 at 4:09 PM
Great postdoc opportunity at LPL w/Sukrit Ranjan on exoplanet atmospheres including "hydrodynamic atmos. escape from rocky exoplanets, N & S cycling on early Mars & Earth, chem kinetics of early Earth, Venus, Mars...& interior-atmosphere interactions on rocky worlds" arizona.csod.com/ux/ats/caree...
Had zero idea until just now about this different Daisy World.
November 16, 2025 at 6:28 PM
Had zero idea until just now about this different Daisy World.
More Tucson problems on the bike trail. Everyone, walkers included, was very chill and just went around behind the rattlesnake.
November 15, 2025 at 8:17 PM
More Tucson problems on the bike trail. Everyone, walkers included, was very chill and just went around behind the rattlesnake.
“I don’t need to bring the bins into the garage since they’ll be smart enough to smell that they are empty.”
November 15, 2025 at 5:56 PM
“I don’t need to bring the bins into the garage since they’ll be smart enough to smell that they are empty.”
The things you can find opening random storage closets in our basement.
November 14, 2025 at 9:19 PM
The things you can find opening random storage closets in our basement.
I'm co-author on a submitted paper that cited another group's modeling infrastructure and included their papers from 2001, 2004, 2006, 2009, 2011, 2013, 2017, and 2020. Reviewer: the actual paper from that group that lays out the model is 2008.
November 14, 2025 at 5:11 PM
I'm co-author on a submitted paper that cited another group's modeling infrastructure and included their papers from 2001, 2004, 2006, 2009, 2011, 2013, 2017, and 2020. Reviewer: the actual paper from that group that lays out the model is 2008.
Reposted by Mark Marley
Avi Loeb's calculations about 3I/ATLAS are 100% wrong because he has never understood that dust in the tail(s) responds to solar radiation pressure. Solar wind shapes the ion tail. But the radiation pressure is about 1000 times larger than the solar wind ram pressure, for particles that feel it.
November 13, 2025 at 9:36 PM
Avi Loeb's calculations about 3I/ATLAS are 100% wrong because he has never understood that dust in the tail(s) responds to solar radiation pressure. Solar wind shapes the ion tail. But the radiation pressure is about 1000 times larger than the solar wind ram pressure, for particles that feel it.
Former LPL Director Tim Swindle and me last night with former NASA astronaut Scott Altman who was CDR on the last two HST servicing missions. He told some hair raising stories about the two missions. Event was awarding of the Astronaut Scholarship Foundation recognition to a fantastic UA undergrad.
November 14, 2025 at 2:40 PM
Former LPL Director Tim Swindle and me last night with former NASA astronaut Scott Altman who was CDR on the last two HST servicing missions. He told some hair raising stories about the two missions. Event was awarding of the Astronaut Scholarship Foundation recognition to a fantastic UA undergrad.
Thanks so much to @luiswel.bsky.social who drove down twice from ASU to give two great lectures to my exoplanets grad class students. Explained both how retrievals work and how easy it can be to engineer the significance to tell the story you want. Plus a bonus visit by @joneskuma.bsky.social
November 14, 2025 at 2:21 PM
Thanks so much to @luiswel.bsky.social who drove down twice from ASU to give two great lectures to my exoplanets grad class students. Explained both how retrievals work and how easy it can be to engineer the significance to tell the story you want. Plus a bonus visit by @joneskuma.bsky.social
Reposted by Mark Marley
"The fallacies behind the cult of Loeb"
New entry in my blog. Other articles have covered the scientific aspects; this one reflects on the social phenomenon. I argue it’s driven by a series of fallacies
tinieblasyestrellas.blogspot.com/2025/11/the-...
New entry in my blog. Other articles have covered the scientific aspects; this one reflects on the social phenomenon. I argue it’s driven by a series of fallacies
tinieblasyestrellas.blogspot.com/2025/11/the-...
The fallacies behind the cult of Loeb
How media hype and misunderstanding fuel pseudoscientific fascination Introduction The word “cult” is used here in the sense given by...
tinieblasyestrellas.blogspot.com
November 13, 2025 at 11:09 AM
"The fallacies behind the cult of Loeb"
New entry in my blog. Other articles have covered the scientific aspects; this one reflects on the social phenomenon. I argue it’s driven by a series of fallacies
tinieblasyestrellas.blogspot.com/2025/11/the-...
New entry in my blog. Other articles have covered the scientific aspects; this one reflects on the social phenomenon. I argue it’s driven by a series of fallacies
tinieblasyestrellas.blogspot.com/2025/11/the-...