Vesta news conference!
We finally got a news conference from the Dawn team reporting on their preliminary findings from the survey orbits of Vesta. Here’s a link to the video (I don’t seem to be able to embed it properly):
Summary of the findings that stood out to me:
- The huge impact basin that takes up most of the southern hemisphere of Vesta is actually two huge impact basins. The main one with the big mountain at the center, which is called Rheasilvia Basin, is overlapping another, slightly smaller and somewhat older impact basin. So Vesta’s southern hemisphere was struck by a huge impactor not just once, but on two separate occasions. The older basin and the mountain in Rheasilvia haven’t been named yet; the mountain is currently just called the “Central Complex” of Rheasilvia.
- The mysterious grooves that gird most of Vesta’s equatorial region are some kind of “ripples” resulting from the impacts. There are two sets of grooves, the main one that circles 2/3 of the planetoid, and an older set in the northern part of the other 1/3. The older set seems to be roughly centered on the older southern impact basin, and the younger equatorial ridges roughly center on Rheasilvia.
- There’s a wide variety of different materials visible on the surface, suggesting a complex geologic history, but no hard evidence yet that Vesta’s mantle is exposed in the impact basins. However, it could be buried under looser regolith (i.e. “soil”). But the geologists are excited at how well Vesta’s surface has retained a record of its complicated history.
So how does this affect what I wrote about Vesta in Only Superhuman? Well, I didn’t really say that much about the planetoid itself, but there is one sentence in Chapter 4 that I’ll definitely have to reword in copyedits, a description of the southern polar “crater” that’s no longer accurate. Hopefully they’ll at least coin a name for the big mountain before the text gets locked down.
What’s surprising to me is how little attention the Vesta mission is getting in the news. It’s been hours since the press conference ended, and it’s very hard to find coverage of it, even on the science news sites. And at the conference itself, even though it went out live over the Internet, there were only a few questions and a lot of dead air during the Q&A period. I mean, this is exciting stuff! Vesta is one of the weirdest, coolest worlds we’ve seen, with all sorts of fascinating features.