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.
How is the universe put together? How is it built? And how does it actually work? Learn how nuclear fusion keeps them burning for billions of years and what powers our nearest star: the Sun. in Part 3 NASA's Parker Solar Probe investigates our Sun.