Meteorites

Meteoroid in space Meteor in atmosphere Meteorite on Earth Meteors?

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

Pribram 1959 Innisfree 1977 How do we know?

Asteroids can be really big Mars Often smash into each other

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 meteorites Stony meteorites –Chondrites –Achondrites Stony Iron Stony

Early Solar System A star explodedA star exploded Bits of the cloud, called a nebula, began to stick togetherBits of the cloud, called a nebula, began to stick together Gravity pulled the lumps togetherGravity pulled the lumps together The lumps gathered more and more rocky dustThe lumps gathered more and more rocky dust They became the planetsThey 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 Has a ‘thumb pressed’ surface Caused by melting due to friction in the atmorpshere This stamp commemorates the fall of this meteorite

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

Achondrites CrustNot differentiated Differentiated Body

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

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 Impact_calculator