[meteorite-list] Australian Desert is Perfect Place to Photograph Fireballs

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Tue Oct 26 12:43:20 2004
Message-ID: <200410261628.JAA09944_at_zagami.jpl.nasa.gov>

http://www.abc.net.au/science/news/stories/s1222754.htm

Oz desert best to photograph fireballs
Heather Catchpole
Australian Broadcasting Corporation Science Online
October 19, 2004

The Australian desert is the perfect place for a crafty camera system
that automatically captures the trails of meteors as they shoot across
the sky, says an international team of scientists.

U.K. researcher Dr Philip Bland from Imperial College London
published the team's results in the current issue
of the journal Astronomy & Geophysics.

Bland and team are from the Desert Fireball Network, which includes
scientists from the U.K., Czech Republic and Australia.

Like other fireball networks since the 1950s, the researchers attempt to
track the orbit of meteors and collect meteorites that fall to Earth.

But only four meteorites have ever been recovered from meteors whose
trails have been photographed, Bland said.

The Desert Fireball Network has built and tested a Czech-built,
prototype camera that automatically takes photographs of the sky, the
first autonomous camera to be used this way.

Humans are needed only to change the camera's film and batteries, which
over one year of testing experienced lightning, dust storms and 45?C heat.

Lovely spot for a camera

The researchers looked at deserts around the world for the perfect place
to put the camera.

Bland said this was the Nullarbor Plain, which stretches about 1200
kilometres across Western Australia and South Australia.

Team member Dr Alex Bevan, curator of mineralogy and meteoritics at the
Western Australian Museum in Perth, said
the surface of the Nullarbor is about 35,000 years old, and is dry most
of the time.

"There's a lack of vegetation, and pale limestone makes the meteorites
easy to spot," Bevan told ABC Science Online.

The team aim to put another two autonomous cameras on the Nullarbor with
the prototype. The extra cameras are needed to triangulate the positions
of the meteors as they streak across the sky.

"Eventually we hope to have five cameras to increase the area of sky
covered," he said.

Monitoring meteors

The photographs give accurate measurements of the velocity, start point
and end point of meteors as they burn up in the Earth's atmosphere,
Bevan said.

"If you can calculate the velocity of the meteor relative to the Earth,
you can get the velocity relative to the Sun and calculate its orbit.

"It also gives us an idea where to look on the ground."

Bevan said they hope to double the number of meteorites discovered
within a few years.

"The more meteor orbits you know, the more likely you are to pin the
source of the meteors down to a particular object in the asteroid belt,"
he said.

He said currently the U.S. and Japan were spending millions of dollars
trying to sample asteroids within the asteroid belt between Mars and
Jupiter.

The Australian cameras would allow scientist to better predict where the
meteors came from and pinpoint certain asteroids, he said.

"You can say this asteroid is interesting, go and look at this."

Bland said scientists have built most fireball networks in their own
countries.

Australia, for example, has had its own network before, but not on this
scale and not with this sophistication.

And in Europe, networks have taken photos of hundreds of meteors, but
the meteorites themselves often end up lost in the vegetation.
Received on Tue 26 Oct 2004 12:28:57 PM PDT