Space rocks in Western Australia

Meteorites

Other planets and rocky material are in orbit around the sun. Some fragments of rocky material exist as small particles called meteoroids which are smaller than asteroids or comets.
Every day, tonnes of this material hit the top of the Earth's atmosphere where friction causes it to heat up and vaporize. This sometimes causes a spectacular display called a meteor shower or shooting star. The larger particles do not completely vaporize and a few hit the Earth. These rocks are called meteorites.
Meteorites are mainly made up of either stone, iron or stony-iron. Which mostly have the same elements we have on Earth such as nickel and iron.

This meteorite was found at Millbillillie in Western Australia and is approx 4,550 million years old (around the same age as the planets). It could from the asteroid Vesta.
It was photographed at the WA museum.

The average meteoroid enters the atmosphere at between 10 and 70 km/sec. But only meteoroids that are larger than a few hundred tonnes are big enough to hit the Earth causing large craters, the rest burn up on entry.

Some meteorites are from the Moon or from between Mars and Jupiter and are called achondrites.

Craters are where the meteorites have hit and this can be seen on the moon and on earth. Other planets in our solar system also have volcanoes.

Meteorite Photographed at the Western Australian Museum.

This is a stony meteorite, achrondrite. It is an igneous rock thought to have come from Mars. It formed approx 1,300 million years ago. This is much younger than other meteorites.

Achrondrites are similiar to basalts.

It was photographed at the Western Australian Museum.

Wolfe Creek, Kimberley WA

Photographed at the Western Australian Museum.

This is a meteorite from Wolfe Creek crater in the Kimberley just east of Halls Creek. This crater is the second largest in the world at 880m across and the floor today is 60m deep. This meteorite is now changed to iron-shale and probably crashed here around 300,000 years ago. The whole meteorite would have weighed more than 50,000 tonnes.

This meteorite is called an Ordinary Chondrite meteorite. It was found on the Nullabor in WA. They are the most common meteorites.
The iron rich chrondrites formed in high temperatures oxygen-poor regions close to the sun whereas the carbonaceous chrondrites probably formed in the cooler outer regions of the solar system.

Chrondrites never heated enough to melt so they are nearly unchanged in their make-up. They are mainly made from the mantle or crust of a planet.

Photographed at the Western Australian Museum.

Tektites

Tektites are not meteorites. They are a natural silica glass formed by melting Earth rocks during giant meteorite impact.

This is the largest Tektite found so far, called Tektite australite from 14.7 million years ago.

Photographed at the Western Australian Museum

This tektite was also found in Western Australia.

Photographed at the Western Australian Museum

Text;

Western Australian Museum Perth. There is a display on meteorites and tektites to see.
http:// www.nineplanets.org/meteorites.html
http:// www.calm.wa.gov.au/national_parks/previous_parks_month/wolfe_creek.html