Asteroids, the Universe, and Everything: Meet 42 space rocks

Between Mars and Jupiter in our solar system lies the Main Asteroid Belt, a region over 150 million kilometers across where most of the biggest asteroids lie. The first, Ceres, was discovered on January 1, 1801, and since then over a million more have been found. There may be a billion or more larger than 100 meters in size.

Because they’re far away and tend to be small, they appear as dots in telescopes — the name "asteroid" means "star-like." That’s been true for decades, centuries really, un...