Minor Members

Things that didn’t make up planets or

moons.

Asteroids• Rocky objects usually larger

than a mile across.• Most are found in the Asteroid

Belt between Mars and Jupiter• Earth has been hit by asteroids

in the past.

Comets• Are mostly made of ice.• Orbit the sun.• Their return can be predicted.• Their tail shows the direction of the

sun, not which way they are headed.

Meteoroids• Small (less than 1 mile) rocks in

space.• When they enter a planets

atmosphere they are meteors.• When they strike the ground, they

are meteorites.

We Have Been Hit• The moon shows it’s record of

impacts because it has no erosion.

• Earth shows only recent signs of impact.

• One major theory says that we were hit 65 MYA and this killed the dinosaurs.

Iridium• Iridium is very rare here on

Earth but plentiful in asteroids.

• A layer of Iridium is found at the K-T boundary (65 MYA)

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