25
votes
3answers
1k views

Why are there no asteroids or meteoroids with relativistic speeds?

Cosmic rays can have energies going into the $10^{20}$ eV domain. Asteroids and meteoroids originating in the solar system are probably limited in their speed because they all started out from the ...
7
votes
3answers
80 views

Are there any Earth-Meteorites on Earth?

A follow-on from this question, if meteorites can come from Mars, it seems they could have come from Earth and ended up back here (though I'm guessing that to be less likely). Do we have any evidence ...
6
votes
2answers
549 views

Are meteorites igneous, sedimentary or metamorphic rocks?

Are meteorites igneous, sedimentary or metamorphic rocks? Or do we need a new method of rock classification for them?