Meteorites Meteors Meteoroid in space Meteor in atmosphere

Meteorites

Meteors? Meteoroid in space Meteor in atmosphere Meteorite on Earth

Where do they come from? Asteroid belt: source of meteorites

How do we know? Pribram 1959 Innisfree 1977

Asteroids can be really big • Often smash into each other Mars

Meteorites are…. • • Samples of planetesimals Samples of asteroids Oldest evidence of our solar system Up to 4. 6 billion years old!

Types of Meteorite stony, iron or stony-iron… Stony Iron Stony-iron

Types of Meteorite Iron • Iron meteorites Stony • Stony meteorites – Chondrites – Achondrites Stony

Early Solar System • A star exploded • Bits of the cloud, called a nebula, began to stick together • Gravity pulled the lumps together • The lumps gathered more and more rocky dust • They became the planets

Chondrite • From the oldest asteroids • Lumps ‘left over’ from when our Solar System formed!

Crusty Chondrite • Can you see the ‘crust’ on this meteorite? • Friction melted the meteorite’s surface as it entered the Earth’s atmosphere

Carbonaceous chondrites • Rare meteorites • Most studied • Formed in the solar nebula 4. 56 billion yrs ago • Contain elemental carbon and amino acids.

Differentiation • Some planetesimals were large • They differentiated into an iron-rich core and a rocky mantle and crust

Iron Meteorite • From the cores of asteroids • Dense iron-nickel • Same material as core of Earth

Iron Meteorite This stamp commemorates the fall of this meteorite • Has a ‘thumb pressed’ surface • Caused by melting due to friction in the atmorpshere

Iron Meteorite • Sliced to reveal the inside • Iron-nickel alloy • Unique pattern of crystals called ‘Widmanstätten’

Not differentiated Differentiated Body Crust Achondrites

Achondrites • From the crust of a planetary body • Created by meteorite impacts • Look like rocks from Earth

Stony meteorite (Achondrite) • Some are from the crusts of asteroids • Others are from the Moon and Mars

Stony meteorite (Achondrite) • This one is actually from the Asteroid Vesta!

Pallasites • Mixtures of iron-nickel alloy and non-metallic minerals • Earth's core/mantle

Stony meteorites (Achondrites) • Look like rocks from Earth • Some are the crusts of asteroids • Others are from the Moon and Mars

Tektites • Earth rocks can be melted on impact • Molten droplets of splashed rock fall back to Earth

Moldavites Source crater Moldavites • A type of tektite found in the Czech Republic • From the Ries crater in Germany • 15 million years old

How to spot a meteorite • Magnetic • No holes or bubbles • Melted outside, silver inside • OR Dark crust, grey inside

Impacts Try the Impact Calculator to see what effect a meteorite impact can have http: //down 2 earth. eu/ Impact_calculator