First orbit of an asteroid this month (around Vesta, with ion drive)

[marcus]

Dawn spacecraft is nearing Vesta and is planned to go into orbit 16 July.
http://science.nasa.gov/science-news/science-at-nasa/2011/06jul_vestamoon/

The craft will orbit Vesta for several months and then move on to another asteroid, Ceres.
The NASA press release mentions that several asteroids have been found to have moons.
For example Ida has a tiny moon. A photo of Ida and its moon is included in the release. Also an early picture taken by Dawn of Vesta itself.

 

[Drakkith]

Nice! Thanks marcus!

 

[tony873004]

Should we start a pool? How many moons does Vesta have? My guess is 2. Soon we'll know!

 

[Drakkith]

1 + or - 1.

 

[marcus]

Drakkith is sure to win One plus-or-minus one covers all the reasonable possibilities, including zero (which is my guess).

According to the latest report, Dawn goes into orbit around Vesta tomorrow, 15 July. It will stay in orbit for about one Earth-year, and then (if all goes well) move on to orbit Ceres.
http://science.nasa.gov/science-news/science-at-nasa/2011/15jul_dawn2/

To me the surface of Vesta (which we are beginning to see in some detail) does not look very interesting. I am more excited by the prospect of our studying Ceres, which is believed to have a lot of water in the form of an ice mantle. One estimate is 200 million cubic km.
http://en.wikipedia.org/w/index.php?title=Ceres_(dwarf_planet)#Internal_structure

This compares with the amount of water in all forms (freshwater, oceans, ice sheets, ground water etc.) on Earth, estimated at 1380-1390 million cubic km.
http://ga.water.usgs.gov/edu/earthhowmuch.html

Ceres is classified as a "dwarf planet", which I expect means that it is inhabited by dwarves
They probably have their houses deep in the ice mantle layer which is thought to be 100 or more km thick.
Dwarves are known to like caves, so that would make sense.

In any case I am a bit more intrigued by the prospect of Dawn studying Ceres. But Vesta (not a dwarf planet with differentiated structure, but a large asteroid) is already interesting. So here we go.

 

[Drakkith]

Do you think the dwarves will accept immigrants? I've always wanted to be the tallest person in the world at 5'7".

 

[marcus]

Do you think the dwarves will accept immigrants? I've always wanted to be the tallest person in the world at 5'7".

I'm sure you realize that as scientists we must base our statements only on firm evidence, not on idle speculation and guesswork. We know that Ceres is inhabited by dwarves, since it is unquestionably a dwarf planet. But so far, at this point, we know nothing about their immigration policy.

=======================

Dawn is now in orbit around Vesta, and we have this photograph
http://science.nasa.gov/science-news/science-at-nasa/2011/18jul_dawn4/

 

[marcus]

Here are some more photographs, some taken from as close as 5000 kilometers.

http://news.yahoo.com/photos/vesta-asteroid-1312296950-slideshow/

The photos show the distinctive "Snowman" feature made of three adjacent craters

The also show bands or grooves, which seem to girdle Vesta. Curious feature. Any comment?

 

[Drakkith]

I think my work likes to do weird things to half the links here at PF, so I can't see any pics yet. I'll have to look when I get home.

But it is definitively interesting with the bands and stuff.

 

[marcus]

I think my work likes to do weird things to half the links here at PF, so I can't see any pics yet. I'll have to look when I get home.

But it is definitively interesting with the bands and stuff.

Sorry Drakkith! the first link I put up was bad. Fixed it.