The "Bigger" Asteroids

[David C]

This is 4Vesta by 'Hubble', perhaps the one we are best aquainted with, as a lot of meteorites originate from it.
However, NASA's JPL has project 'Dawn' approaching Vesta, and is just about to go into orbit around it, and we hope it will provide some great 3D pics!
The other picture is a 3D simulation of Vesta by the NASA scientists. Vesta is also regarded as a 'Protoplanet'.

[David C]

This is probably my favourite, Itokawa, no bigger that 600yds long, it looks as if two bodies attached by each others gravitational pull have 'merged'. I would suggest that this asteriod is also highly magnetic, as the space rubble attached seems to have just stuck!

[David C]

Eros, another 'biggie':

[David C]

Gaspra, one more big one.

[David C]

...and one more - Phobos

[Matt Smith]

I would suggest that this asteriod is also highly magnetic, as the space rubble attached seems to have just stuck!

Erm..... much as I hate to be picky I think we can be pretty confident that gravity is solely responsible for holding rubble pile asteroids together!

Edited to add: and Phobos is a moon, not an asteroid, although it may have been an asteroid prior to being captured by Martian gravity.

[David C]

Matt,,do you honestly think that something 600yds long has a 'gravity'? I don't think so. Unless a magnetic field can be defined as gravity. Look at all the rubble that has attached itself, and the random way it has happened.
Phobos and Deimos are small Asteroids, that act like a moons in orbit around Mars

[Matt Smith]

Matt,,do you honestly think that something 600yds long has a 'gravity'? I don't think so. Unless a magnetic field can be defined as gravity. Look at all the rubble that has attached itself, and the random way it has happened.
Phobos and Deimos are small Asteroids, that act like a moons in orbit around Mars

Asteroids orbit the Sun, moons orbit planets. Therefore Phobos and Deimos are moons.

Any object with mass will have a gravitational field, the force from a 600m object may be small but in the absence of any other force it will be more than sufficient to hold a loose pile of rocks together. Remember that the whole solar system formed from a cloud of dust and gas attracted together by gravity. Gravity was sufficient even on those microscopic particles to pull them together, the tiny forces involved are not a problem.

[Barwellian]

I believe that there is a good video somewhere demonstrating that very fact when one of the astronauts aboard the space station was experimenting with dust, or was it salt or similar which was shaken up in a poly bag and then low and behold it gradually clumped together.

Graham

[Barwellian]

Actually, slight correction, I believe the initial forces attracting such small particles were believed to be electrostatic and gravity played its part later.

See videos etc here...

http://www.skyandtelescope.com/news/330 ... page=1&c=y

I like the last comment when asked if Jupiter might be made in such a way he replied he would need a bigger bag!

Graham