4 Vesta Options

[Jeffrey]

I read somewhere that when Dawn gets to Vesta it might be able to determine if it's spherical as Ceres is, and thus qualify to become another dwarf planet. Now that I hear Dawn might head off to Pallas, that makes me wonder if what I read for some time previous, and that Vesta has already been visited. Though if it were spherical and thus another dwarf planet I probably would have read about it by now.

Are there any cylindrical maps of Ceres out there? Thanks to jumpjack I now have icosahedra and gores of all the spherical satellites as well as all the planets and the Sun, so all I'm now missing is Ceres.

[ynyralmaen]

No, Vesta hasn't been visited yet; from HST observations, it doesn't look very spherical. Nice rotation movie also here.

[Greg Hullender]

Jeffrey: Sounds like you need to be reading better sources! :-)

Why not start with the material on the Dawn web site?

http://www.dawn-mission.org/mission/background.asp

That'll tell you that no mission has been to Vesta before and there's no chance it's round.

You might also check their FAQ's

http://www.dawn-mission.org/mission/faqs.asp#

In particular, this would tell you that they have no intention of visiting Pallas.

--Greg

[Patteroast]

Correct me if I'm wrong, but I was under the impression that there was still some debate as to whether Vesta might qualify as a dwarf planet, depending on whether it had achieved hydrostatic equilibrium before the giant impact at the south pole.

Wasn't the Pallas thing just an extended mission idea some people were tossing around?

[Greg Hullender]

I suppose a lot depends on what you mean by "debate." Do you mean is there debate within this forum? If so, sure; people have speculated about both ideas -- and convincingly ruled both out, in my opinion. But if you mean is there debate in the literature, then the answer seems to be no. I just did a search at the University of Washington library (including materials held at libraries worldwide) for papers since 2003 with "Vesta" and "Asteroid" in them. There are only a dozen, and none proposes it might have been in hydrostatic equilibrium. And if you mean is there debate within the Dawn team, they seem to have already answered this on their web site -- unless they've changed their minds since then.

--Greg

Edit: "Dawn: A Journey in Space and Time" (Russell; 2004), suggests Vesta, although not round, is a differentiated body with a metallic core and a history of melting. It refers the reader wanting more details to 'Geological history of asteroid 4 Vesta: The "smallest terrestrial planet"' (Keil K; 2002), which might be of interest. It's not available online, but it's collected in "Asteroids III," which is in the stacks at UW. I'll see if I can get a look at it today.