Michael BuschApr 20, 2025

I am wondering if #Donaldjohanson will look something like Toutatis or 2003 SD220. Or maybe it will be more like a small Mathilde.

QT Dr. Raphael Marschall @spacemarschall.net‬
2025 April 19

What can we expect from tomorrow's flyby of Lucy at asteroid Donaldjohanson (DJ)?

I bet that we are going to see a weird object!

Why? There are two peculiar things we know:

DJ rotates very slowly (period = 251 h)
DJ has a large light-curve amplitude (~1 mag)
https://bsky.app/profile/spacemarschall.net/post/3ln625qbs522o

Dr. Raphael Marschall (@spacemarschall.net)

What can we expect from tomorrow's flyby of Lucy at asteroid Donaldjohanson (DJ)? I bet that we are going to see a weird object! Why? There are two peculiar things we know: 1️⃣ DJ rotates very slowly (period = 251 h) 2️⃣ DJ has a large light-curve amplitude (~1 mag) 🧵 1/3 #PlanetSci #SciComm

Bluesky Social
Show threadMichael Busch

Asteroid #Donaldjohanson is like #Toutatis .

https://science.nasa.gov/image-article/nasas-lucy-spacecraft-images-asteroid-donaldjohanson/

NASA’s Lucy Spacecraft Images Asteroid Donaldjohanson

In its second asteroid encounter, NASA’s Lucy spacecraft obtained a close look at a uniquely shaped fragment of an asteroid that formed about 150 million

NASA Science
Apr 21, 2025 at 6:46pmWeb
Show threadMichael BuschApr 21, 2025

This animation of some of the #LucyMission images of main-belt asteroid #Donaldjohanson from yesterday is too high-resolution for Mastodon to accept for embedding:

https://assets.science.nasa.gov/content/dam/science/missions/lucy/djencounter_movie_release_v2.gif

Good problems to have?

Show threadMichael BuschApr 21, 2025

Donaldjohanson looks like it may have more craters per unit area than Toutatis, which would be expected given the longer YORP timescale and the impact rate in the Main Belt.

But I defer to the crater counting experts.

Show threadV MartínApr 21, 2025

@michael_w_busch a conversion to mp4 is good enough in this case while we wait for the highres data 😉

https://mastodon.social/@sharponlooker/114377679103602831

Show threadsimonbpApr 21, 2025
@michael_w_busch And Braille, which is even closer in size.
Show threadMichael BuschApr 21, 2025

@simonbp

Braille is only ~2 km long; versus ~5 for Toutatis and ~8 for Donaldjohanson?