Asteroids: Crash Course Astronomy #20

Now that we’ve finished our tour of the planets, we’re headed back to the asteroid belt. Asteroids are chunks of rock, metal, or both that were once part of smallish planets but were destroyed after collisions. Most orbit the Sun between Mars and Jupiter, but some get near the Earth. The biggest, Ceres is far smaller than the Moon but still big enough to be round and have undergone differentiation. CORRECTION: In the episode we say that 2010 TK7 is 800 km away. However, 2010 TK7 stays on average 150 millio