Researchers from the Western Australian Museum, the Imperial College in London and Ondrejov Observatory in the Czech Republic have identified a unique meteorite and its orbit in the Solar System.

The meteorite was tracked through a network of cameras as it fell to Earth in July 2007. The cameras take a single time-lapse picture every night to record any fireballs in the sky.

The Desert Fireball Network Project of All-Sky Cameras is set up in the Nullarbor Plain to monitor incoming meteors and track any possible meteorites to the ground so scientists can recover them.

When a meteorite falls to Earth the researchers use complex calculations to determine its orbit and where it was likely to have fallen so they can retrieve it.

Dr Alex Bevan, Head of Earth and Planetary Sciences from the WA Museum is a co-researcher on the project. He and his staff have been involved in the project since its inception in 2006.

When Dr Bevan and his co-researchers received the film from the meteorite fall in 2007 they were able to view the time-lapsed photo showing the fireball and its trajectory as it fell to Earth.

On their first expedition to the desert the researchers discovered three fragments of the meteorite within 100m of the predicted site. Known as Bunburra Rockhole the fragments are between the size of a cricket ball to the size of a golf ball.

The Western Australian Museum currently has one fragment of the meteorite while the other two fragments are on loan in Europe.

The subsequent research and calculations of this meteorite fall have determined it was following an unusual orbit around the Sun.

The research team believe it started out as part of the asteroid in the innermost main asteroid between Mars and Jupiter. It then gradually evolved into an orbit around the Sun very similar to Earth’s. The data researchers have other data for show meteorites follow orbits that take them back, deep into the asteroid belt.

“This research is incredibly exciting,” Dr Bevan said.

“For the majority of meteorites we have found we have little or no information about where they came from in the Solar System or their path to Earth.

“Through this project we were able to track and predict the location of the meteorite fall based only on instruments. If it were not for this research we may never have known about this meteorite falling let alone where it came from or its orbit to Earth,” he said.

The Bunburra Rockhole is unusual because it is composed of a rare type of basaltic igneous rock. The researchers say that its composition, together with the data about where the meteorite comes from, fits with the recent theory about how the building blocks for the terrestrial planets were formed.

Chief executive officer of the WA Museum Diana Jones said the research as a great coup for Western Australia and an important project for scientific research into our Solar System.

“The All-Sky Cameras project really is an extraordinary project and opens a great deal of possibilities for future research,” she said.

The findings of the Desert Fireball project will be published in Science magazine today. http://www.sciencemag.org

Renae Woodhams
Manager, Media and Communications
Western Australian Museum
Tel: 08 9212 3860
Mob: 0439 948 779
Email: renae.woodhams@museum.wa.gov.au