Sean Raymond (planetplanet.net)

Like dinosaurs, Saturn and Jupiter roamed They sculpted this system that humans call home The gas giants roared, the system unstable An ice giant planet fell right off the table! A whole ring of comets was launched to the stars The planets — bombarded — still bear the scars.

And Lift Off! A glorious launch of #MMX, the start of an amazingly awesome 5 yr round trip to Mars' moon Phobos. 1yr to get there, 3yrs exploration landing on the surface (twice), then 1yr to get home with the bounty (2tbls of Phobos dust), arriving in the Australian outback in 2031! 🥳🔭🧪🛰️🚀

Thanks Phil Plait for writing about our paper about "constellations of co-orbital planets" for Scientific American! www.scientificamerican.com/article/how-... And if you want all the animations, see my blog post about it: planetplanet.net/2023/04/20/c...

We've made a starter pack of Nautilus contributors! A great way to jumpstart your Bluesky experience with great science minds. go.bsky.app/RbETK5c

A couple of great talks coming at the @labastrobordeaux.bsky.social on Fri Oct 2. Make sure to sign up first! smr.u-bordeaux.fr/departement-...

Named for NASA's first chief astronomer, the Nancy Grace Roman Space Telescope is expected to reveal new information about the expansion of the universe and discover multitudes of planets orbiting distant stars. #NASARoman 🔭

Published version of our new review on planetary ejection (led by @malenarice.bsky.social, and with Will DeRocco) is out now! iopscience.iop.org/article/10.1...

I needed something spectacular, and here it is: a view of the August 12 solar eclipse as seen from South Korea's Danuri satellite, in orbit around the Moon. You can see the lunar shadow sweeping across Greenland. 🔭🧪 www.mt.co.kr/amp/tech/202...

This is a pleasing factoid: the Nancy Grace Roman space telescope is the same size and weight as a T-Rex! Countdown: 15 days to launch! 🚀 AUG 30, 2026 11:26 UTC ℹ️: science.nasa.gov/mission/roma...

In this new paper we showed that interstellar objects can be captured as a byproduct of stars flying by each other in the Galaxy (no planets involved). It only works for strong-enough encounters, probably just a few for the Sun during its history. It means that all stars have (sparse) Oort clouds

I fell asleep and forgot my June 15th tradition of reminding the world that something amazing may have happened on June 15, 2014 -- but no one on Earth saw it.. planetplanet.net/2014/06/04/s...

For #AsteroidDay, here is a good ol' poem about, well, asteroids! planetplanet.net/2020/06/30/a...

A nice write-up of a new paper by Nate Kaib and myself by @starstryder.space. The punchline: the orbits of long-period comets appear to hold a signature of the flyby of the star HD 7977, which happened 2.5 million years ago! phys.org/news/2026-06...

I never thought I'd get the chance to shake hands with the president and have a one-on-one chat -- for a solid 15 seconds, during which one subject of conversation was, indeed, my tie (thanks to Marisa for suggesting it!)

Left: the comet in Deep Impact (1998) Centre: the comet in Armageddon (1998) Right: an actual, real-life comet (2015)

@elizabethtasker.bsky.social made an amazing and amazingly clear all about sample return mission from asteroids. Well worth your time!

I love this new paper about planets in AGN disks around supermassive black holes! arxiv.org/abs/2605.19241 Naturally, it also helps to motivate some of the crazy planetary systems I've built: planetplanet.net/2018/06/01/t...

For your Monday, here's one of the JWST Deep Field images. This is a portion of the sky about one-fifth the size of a full Moon. And it contains THOUSANDS of galaxies—some of which extend back to when the Universe was a couple of billion years old. The redder a galaxy, the farther away it is.

This week in my "Planets in Science Fiction" class, I will be discussing the amazing short story "Nightfall" by Isaac Asimov and its insights into the nature of scientific bias. Also be sure to check out the incredible work of @planetplanet.bsky.social at planetplanet.net.

It's official. I just took over as the new director of the Laboratoire d'Astrophysique de Bordeaux (@labastrobordeaux)! It's a whole new gig -- wish me luck!

Last week, my son Zack shadowed me at my department for a week. I put him to work but I gave him a choice -- and he decided to simulate rings of planets and stars orbiting a black hole. And he wrote a blog post about it for your reading enjoyment (with gif!) planetplanet.net/2025/12/13/b...

About 100 billion humans have walked the Earth. About 100 billion stars roam the Milky Way galaxy. About 10,000 humans have ever been paid to study the stars (if anyone has better data let me know). So, modern astronomers are each lucky to the tune of 1 in 10 million!

I just realized that a couple weeks ago was the fifth anniversary of the release of my astronomy poem book: Black Holes, Stars, Earth and Mars. www.amazon.com/dp/B08LFZZWGZ

nautil.us/the-nautilus...

New animation of the ultimate engineered solar system for a talk I'm giving tomorrow at a sci-fi convention in Lithuania. It has 400 rocky planets in the habitable zone of a single Sun-like star It's perfectly stable (I simulated it out to about a billion years) planetplanet.net/2017/05/03/t...

AAS members are on the Hill today to #SaveNASAScience and advocate for sustained funding for NASA, NSF, and our nation's other science agencies! Help us amplify their voices by calling and writing to your Congressional offices today: aas.org/action-alert...

In my new @nautil.us article, I use a lot of recent research to argue that rocky exoplanets on eccentric orbits are often very good candidates for life. (At least, eccentric/inclined orbits should not be used as a negative for habitability) nautil.us/wild-orbits-...

Here's something new and weird -- eccentric rings of co-orbital planets. They are stable indefinitely, from an orbital point of view. Could they actually form and exist? planetplanet.net/2025/09/02/e...

Flashback to 2012 when I ate the Sun (Photo from the top of Vulcano in Sicily)

Sigh. sites.psu.edu/astrowright/...

Still can't get over @deschscoveries.bsky.social parodying Loeb, and Loeb straight-up playing out the parody a 3 days later. Is Desch a clairvoyant, or did Loeb read this mockery of him and think—hey, that's actually a great idea!—and just plagiarize him?!

My complaints have not yet been resolved. medium.com/@steve.desch...

Loeb’s bad science flies out faster than any one of us should have to deal with it. For a nice explanation of what’s wrong with many of his claims I have not addressed, see @hectorsocas.bsky.social ’s work here: tinieblasyestrellas.blogspot.com/2025/08/3iat...

Today, *every* living prior leader of NASA's science directorate have released a joint letter condemning the proposed cuts to NASA science. These individuals every administration from Reagan to Biden, and all believe these cuts are insanely destructive: www.planetary.org/press-releas...

Folks need to remember that public funding of science drives economic growth and human quality of life decades into the future. This is about more than saving jobs on the line now. It's about your future health, and the future of health and well-being for the next several generations.

The details are not yet finalized, but the budget bill would devastate NASA science and the future of US exploration in space and astronomy. Among many other things. 🔭🧪 www.planetary.org/articles/nas...

Oh hey I didn't know you were here! I wrote about it too. 😄 www.scientificamerican.com/article/coul...

@nytimes.com article about Nate Kaib's and my recent paper on the future stability of the Solar System when passing stars are accounted for. www.nytimes.com/2025/06/28/s...

I was the scientific advisor for the latest video by Balade Mentale about "World-Killer Planets: The Chaotic History of Planetary Systems" (in French) youtu.be/_6J9axX3r08?...