Asteroooooid De-FENSE!

Asteroids are rocky bodies in our solar system that either failed to form into planets during the early universe or are fragments of smashed planets. Most asteroids orbit in the belt between Mars and Jupiter, with over 1.8 million known asteroids ranging from 30 feet to several hundred kilometers in radius. NASA tracks about 25,000 near-Earth asteroids, discovering roughly 1,100 new ones annually.

• Asteroids are either ancient pieces meant to become planets but never did, or smashed remnants of early planets
• Most asteroids are trapped between Jupiter and Mars in the asteroid belt
• Over 1.8 million known asteroids exist, with 25,000 classified as near-Earth asteroids
• NASA discovers about 1,100 new near-Earth asteroids every year

In the 1770s, astronomer Johan Bode discovered a mathematical sequence explaining planetary distances from the sun, which suggested a missing planet between Mars and Jupiter. In 1801, Italian astronomer Giuseppe Piazzi discovered Ceres, the largest asteroid which comprises one-third of the entire asteroid belt's mass. Jupiter's immense gravitational pull has broken these objects into increasingly smaller pieces over time.

• Johan Bode's mathematical sequence in the 1770s predicted a missing object between Mars and Jupiter
• Giuseppe Piazzi discovered Ceres in 1801, noticing it was darker than other planets
• Ceres is 620 miles (1,000 kilometers) across and makes up one-third of the asteroid belt's total mass
• Jupiter's gravitational pull breaks asteroids into smaller and smaller pieces