Meteors and meteorites

Meteorites are some of the oldest rocks in our solar system and studying them helps us understand how the solar system was formed.

Do you know your meteorites from your meteors? Your stony meteorites from your iron meteorites? Take our quiz to test your knowledge!

Meteor shower. — Image: Bill Ingalls / NASA

Although they are both rocks from space, what is the main difference between a meteorite and a meteor? 

A meteorite breaks through the atmosphere to strike the Earth’s surface, whereas a meteor burns up before reaching the ground.

Each year, thousands of meteors enter Earth’s atmosphere, many of them burning up before impact. The ones that do reach the Earth’s surface are called meteorites.

Most meteorites go unnoticed—many are made up of tiny sand-grain sized particles and will land in the ocean or unpopulated areas. Around 16 meteorites per year are witnessed falling and then recovered. Large meteorites can create massive craters in the Earth and cause widespread destruction.

A meteor breaks through the atmosphere to strike the Earth’s surface, whereas a meteorite burns up before reaching the ground.

A meteor is significantly larger in size than a meteorite.

A meteorite is significantly larger in size than a meteor.

Which of the following rocks is a meteorite? 

Volcanic bomb from Mount Noorat, an extinct volcano.

Moon Rock (on loan from NASA's Johnson Space Centre, collected during Apollo 15 moon landing in July 1972), on display at Dynamic Earth exhibition.

Murchison meteorite. Class: Stony. Group: Carbonaceous Chondrite. Type: CM2. Location: Australia, Victoria, near shearing shed, Pranjip Park, Murchison.

Meteorites can be tricky for people to identify and there are many different types. Some are dense and heavy, like iron meteorites, while others that have been on Earth a long time will become weathered and look very similar to Earth rocks. This meteorite is a piece of the Murchison meteorite. In 1969, hundreds of fragments of meteorite fell from the sky around the little town on Murchison in Victoria, with many residents collecting pieces shortly afterwards.

Where do most of Earth’s meteorites come from? 

The moon

The Kuiper belt in the outer solar system

Supernova explosions (the death explosions of huge stars) 

The asteroid belt between Mars and Jupiter

Although some incredibly rare meteorites are fragments of the Moon, Mars or comets, most of the meteorites that land on Earth come from the asteroid belt between Mars and Jupiter.

What species was wiped out by the impact of a colossal meteorite around 65 million years ago? 

Erbenochile erbeni, triobite, fossil. Location: Foum Zguid district, Morocco. Timrhanrhart Formation, Lower Devonian. Reg. no.: P 332725.

Trilobites

Colour illustration of the dinosaur Tarbosaurus bataar in a natural setting.

Dinosaurs

Megafauna

Thylacine, Thylacinus cynocephalus from J. Gould's Mammals of Australia, 1863, vol 1, pl 54

Thylacines

The huge asteroid that scientists believe struck Earth 65 million years ago marked the end of the Cretaceous period and caused the mass extinction of dinosaurs, pterosaurs, and many marine reptiles and marine invertebrates. It was approximately 10km wide and made a crater that was a whopping 150km in diameter. Enormous dust clouds generated by the impact would have blocked out much of the Earth’s sunlight, causing plants to die and affecting the food chain for most animals. 

Which of the following Australian landscapes was shaped by the impact of a meteorite? 

Mt Noorat, near Terang is one of the best preserved extinct volcanoes in Victoria.

Mt. Noorat, VIC 

Wolfe Creek, WA

Aerial view of Lake Keilambete, maar volcano with tuff ring northwest of Terang.

Lake Keilambete, VIC

Field site, Muldoons Sinkhole, Lake Condah. Location: Australia, Victoria, Budj Bim National Heritage Landscape, Lake Condah, Muldoons. Survey: BBLC 405.

Muldoons Sinkhole, Budj Bim National Heritage Landscape, VIC

The Wolfe Creek crater in Western Australia is about 1km wide and 60 metres deep. Geologists estimate it was created approximately 300,000 years ago by a meteorite weighing 50,000 tonnes (the weight of around 250 blue whales!).

Representations of the Wolfe Creek crater are prominent in the art and stories of the Djaru people, an Indigenous group from the Southern Kimberley region. The largest meteorite crater in Australia
(and one of the largest in the world) is Lake Acraman in South Australia, 90km in diameter.

What is the most common type of meteorite found on Earth? 

Stony meteorites

Henbury meteorite. Class: Iron. Group: Octahedrite, medium. Type: Iron, IIIAB. Location: Australia, Northern Territory, Henbury Meteorite Craters .

Iron meteorites

Esquel Stony iron meteorite (Pallasite). The green crystals are olivine set in a iron-nickel alloy.

Stony-iron meteorites

All of the above

Meteorites are grouped by their compositions. 95% of meteorites are made up largely of silicate minerals, and these are called stony meteorites. This stony meteorite is another example of the Murchison meteorite. Meteorites can also be composed of iron and nickel (iron meteorites), or a mixture of metal and silicate minerals (stony-iron meteorites). Meteorites provide clues to the formation of our solar system.

Shooting stars and falling stars are actually meteors. True or false?

True

What we know commonly as shooting stars or falling stars actually have nothing to do with stars at all! They are small grains of rock and dust burning up as they hit the atmosphere at high speed. Meteor showers, where you can see multiple ‘falling stars’ at once, occur regularly during the year when the Earth passes through patches of dust and debris left behind by comets. Each year as Earth orbits the sun, we move through the same patches of dust, and this is how scientists can predict when meteor showers will occur.

False

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Credits: Images sourced from Museums Victoria and NASA.

Meteors and meteorites

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