Meteorites. Meteoroid in space Meteor in atmosphere Meteorite on Earth Meteors?

Meteorites

Meteoroid in space

Meteorin atmosphere

Meteorite on Earth

Meteors?

Where do they come from?

Asteroid belt: source of meteorites

Pribram 1959

Innisfree 1977

How do we know?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 Types of MeteoriteMeteorite

stony, iron orstony-iron…

Stony

Iron

Stony-iron

Types of Meteorite

• Iron meteorites

• Stony meteorites– Chondrites– Achondrites

Stony

Iron

Stony

Early Solar SystemEarly Solar System • A star explodedA star exploded• Bits of the cloud, Bits of the cloud,

called a called a nebulanebula, , began to stick began to stick togethertogether

• Gravity pulled the Gravity pulled the lumps togetherlumps together

• The lumps The lumps gathered more and gathered more and more rocky dustmore rocky dust

• They became the They became the planetsplanets

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 Carbonaceous chondriteschondrites

• 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 MeteoriteIron Meteorite• Sliced to reveal

the inside• Iron-nickel alloy • Unique pattern of

crystals called ‘Widmanstätten’

Achondrites

CrustNotdifferentiated

DifferentiatedBody

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!

PallasitesPallasites• 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

http://down2earth.eu/Impact_calculator