Strange Asteroids Baffle Scientists

Raver32 writes to mention that two nearby asteroids may be evidence of a new class of asteroid or long eroded mini-world. Mineral evidence gathered using photometric data shows these asteroids to contain basalt not normally found in asteroid belt objects. "The lack of basalt and another mineral, olivine, in asteroid belt objects has long puzzled scientists. These two minerals would have formed the crust and mantle, respectively, of belt objects the size of Vesta or larger; theory predicts that more than half of all asteroids should be composed of one or the other of these substances"

Comments

Re:interesting

[jamstar7]

Or, some of these objects could be formed as a result of collisions. Just Googled Vesta, for instance, and at 525 km, it's pretty big for a projectile thrown clear from an impact:

Vesta is the most geologically diverse of the large asteroids and the only known one with distinctive light and dark areas -- much like the face of our Moon. Hubble images have revealed a diverse world with ancient lava flows and a gigantic impact basin that is so deep, it exposes the asteroid's subsurface, or mantle. Vesta's surface shows a geology similar to that of terrestrial worlds such as Earth and Mars. Ground-based spectroscopy of Vesta indicates regions that are basaltic, which means lava flows once occurred on its surface. This is surprising evidence that the asteroid once had a molten interior, like Earth does. This contradicts conventional ideas that asteroids are essentially cold, rocky fragments left behind from the early days of planetary formation.

Seems to me that if some of these basalt asteroids are chunks left over from a collision, the target of the collision would likely be in bad shape. Could the remainder of the Main Belt asteroids be the pieces of the target? Sign me up to go check 'em out...

Re:Wish more people would fess up their bafflement

[geekoid]

The other thing being the desire to disprove hypothesis of the new observation.

This is odd

[PPH]

From the article:

"The lack of basalt and another mineral, olivine, in asteroid belt objects has long puzzled scientists. These two minerals would have formed the crust and mantle, respectively, of belt objects the size of Vesta or larger; theory predicts that more than half of all asteroids should be composed of one or the other of these substances"

It would appear as though the above 'theory' is incorrect if, up until now, very little basalt has been detected. Perhaps the material in the asteroid belt never went through the planetary formation stages necessary to form such rocks (volcanism).

The presence of this new class of material might suggest that the asteroid belt is made up of the remains of a small planet (moon perhaps) plus lots of additional garbage that never formed a planet.