astrafoxen

tiny correction:
I accidentally mixed JPL's 3-sigma uncertainty with Deen's 1-sigma uncertainty. Values are correct, but it'd be more appropriate to express them with same sigma.

JPL's 1-sigma uncertainty would be ±773 km (divide 3-sigma by 3), compared to Deen's 1-sigma uncertainty of ±49 km.

A mission to YR4 would definitely be nice! Right now the missions are only concepts and it's too early to say if they'll actually happen.

This NASA paper mentions there's still value in sending a mission to YR4 even after lunar impact is ruled out. ntrs.nasa.gov/api/citation...

There's the possibility of nongravitational forces directing YR4 closer to the Moon, but it's unlikely they'd be strong enough to push it toward collision.

Deen's paper mentioned that Yarkovsky forces (reemitted sunlight pushing the asteroid) could bring YR4 as close as
19189±3537 km to the Moon.

The 21,200 km Moon close approach distance reported in the NASA press release isn't quite accurate and doesn't include uncertainties, so I'm directing you to the JPL Small Body Database page for 2024 YR4 instead. It's updated with the new JWST observations. ssd.jpl.nasa.gov/tools/sbdb_l...

Now that the news are out...

Rivkin's Feb 2026 JWST observations of asteroid 2024 YR4 shows that it'll pass 21,938 ±2,320 km from the Moon (according to JPL SBDB), while Deen's precoveries from 2016 found that YR4 will pass of 22,001 ±49 km from the Moon.

Both independent results are spot on! 🔭☄️

real

(damn I wish I could find the actual email where I submitted the proposal. I probably sent it through my now-deleted elementary school district email or through a web form on the MPC website, which could the reason why it's lost now)

if you don't believe me, i don't blame you lol

i'm not gonna defend it

I named an asteroid after Cary Huang (that guy from @jacknjellify.bsky.social)

all I did was write the name proposal and email it to the IAU WGSBN back in February 2021 cause I was bored during COVID lockdown. It got accepted in June 2021 somehow

MORE underrated astro Youtubers! Subscribe to them please! (1)
* Geo Girl (geology/planetary) youtube.com/@geogirl
* Dr. Fatima (academia/politics) www.youtube.com/@dr.fatima
* Oge Okoronkwo (PhD vlogs) www.youtube.com/@ogeokoronkwo
* Syzygy "Z" Altair (Vtuber) www.youtube.com/@SyzygyAltai...

(2)
* Nora's Guide to the Galaxy www.youtube.com/@NorasGuidet...
* Astro Kirsten www.youtube.com/@astrokirsten
* Sixty Symbols www.youtube.com/@sixtysymbols
* Deep Sky Videos www.youtube.com/@DeepSkyVideos
* Sci Facts for Sci Fics youtube.com/@scifactsfor...
* Kyplanet www.youtube.com/@Kyplanet893

MORE underrated astro Youtubers! Subscribe to them please! (1)
* Geo Girl (geology/planetary) youtube.com/@geogirl
* Dr. Fatima (academia/politics) www.youtube.com/@dr.fatima
* Oge Okoronkwo (PhD vlogs) www.youtube.com/@ogeokoronkwo
* Syzygy "Z" Altair (Vtuber) www.youtube.com/@SyzygyAltai...

YouTube video by JayChoken The Weird Worlds of Gliese 876

Hi yall! Please check out JayChoken, he's a super underrated worldbuilding Youtuber who makes videos about exoplanets! :D

He's approachable, straight to the point, & shows his analysis of sources with proper visuals, unlike most astro Youtubers. No drama-doc BS here! www.youtube.com/watch?v=5G7P...

sorry for the even more belated response..
but yes, you can predict/estimate how much moons above a certain radius exist! A 2021 study did that and previously predicted that Saturn should have 150±30 outer moons larger than 1.4 km radius (more moons than Jupiter) iopscience.iop.org/article/10.3...

i see this as an absolute win :3

Some stuff I did for the first 3 days of @morgandenman.bsky.social's #SpacetoberChallenge! Been too busy with college so I can't do these on time blehhhh

(I'll post these individually later)

(update)
This teeny meter-wide asteroid C15KM95 was officially announced with the new name "2025 TF" today! minorplanetcenter.net/mpec/K25/K25...

(and a neat photo of the asteroid by @filipp-romanov.bsky.social over at: bsky.app/profile/fili...)

Now to wait an hour until this gets on Wikipedia...

nyoooom

A moderate bright point-source in the middle and smaller sources around them, labeled with dates.

Dwarf Planet #Quaoar and its moon #Weywot with #Hubble WFC3/UVIS filter F350LP. Quaoar is located in the Kuiper Belt (beyond planet Neptune).

I combined different epochs and oriented them with north being up. I removed stars. The moon changed position during its orbit around the #DwarfPlanet.

Small preview of color photographic map of Pluto in Mollweide oblique projection. It contains one large global map with four small hemispheric maps and basic description. Full version of this map is available for download in links in the main post. Credit: NASA/JHU-APL/SwRI/Marc W. Buie/ESA/Daniel Machacek.

My new color photographic map of Pluto is now online.

Full resolution image version (~322Mpix) is available on Flickr www.flickr.com/photos/10958...
PDF version (~73MB) is available here: drive.google.com/file/d/1EW-x...

🧵 1/5

More attention, views, & clicks = more ego and money (ad revenue i guess?)

I only look for astro news from places that I know are reliable (phys.org, arxiv, anton petrov, space.com, etc.), so idk what weird stuff ppl are saying elsewhere. From experience, reddit and tiktok are absolute garbage lmao

ooooo hypeeee!!

yeah... genuinely sad that there's actual fearmongering. Personally I find 3I/ATLAS super fricking awesome!

(tho not as weird as the nitrogen & carbon monoxide-rich blue comet C/2016 R2 and the explodey comet 29P/Schwassmann-Wachmann... I've been hyperfixating on these two and THEYRE SO WEIRDDD)

As one of the people (who had been) actively updating the 3I/ATLAS Wikipedia article, thanks! :D

Mike Kelley describes spectra of the icy surface of comet Hale-Bopp, taken at a distance of 46 AU (!!) with JWST 🔭 : similar to Water-type TNOs but with organic features

heck yeah Makemake getting that makeover from JWST!
So now we have evidence of geochemical activity, a cryovolcanic hotspot, and a potential atmosphere.

I swear if Makemake turns out to also have rings or a second moon, it's gonna become my 4th favorite dwarf planet

Mimas science is serious business

Lucy image of asteroid Donaldjohanson, with features labeled with their formal names approved by the IAU

A screenshot of the IAU's announcement of 11 new names for Donaldjohanson's surface+shape features. The text reads: 11 Names Approved for (52246) Donaldjohanson: Afar Lobus, Olduvai Lobus, Hadar Regio, Minatogawa Regio, Luzia Dorsum, Boxgrove Saxum, Kennewick Saxum, Cashel Saxum, Mungo, Narmada, and Windover Collum 08/27/2025 The IAU Working Group for Planetary System Nomenclature has approved the names Afar Lobus, Olduvai Lobus, Hadar Regio, Minatogawa Regio, Luzia Dorsum, Boxgrove Saxum, Mungo, Narmada, Kennewick Saxum, Cashel Saxum, and Windover Collum for eleven features on the asteroid (52246) Donaldjohanson. For more information, please see the Donaldjohanson nomenclature map in the Gazetteer of Planetary Nomenclature.

The IAU announced official names for Donaldjohanson's surface & shape features 2 weeks ago, but nobody has mentioned the news. They're all named after archeological sites and hominin fossils, which is fun and awesome haha

(Afar Lobus = small lobe, Olduvai Lobus = big lobe, Windover Collum = neck)

Today on arXiv: The recent JWST TRAPPIST-1 e papers.

They are somehow not even the biggest news in the list. Today's arXiv day's absolutely stacked.

bwehh i haven't gotten to reading it yet lol