London: Astronomers have discovered a
specific piece of meteorite on Nullabor Plain, after tracking
it from orbit, a rare finding which they claim is a major
breakthrough for planetary science.
An international team, led by Phil Bland of Imperial
College London, has spotted not only a tiny meteorite on the
Nullarbor Plain, but also its orbit and the asteroid it came
from, using cameras which capture fireballs streaking across
the night sky and mathematics, the `Science` journal reported.
The astronomers deployed three "all sky cameras"
on the Nullarbor Plain to form a fireball camera network. The
cameras take a single time lapse picture of the sky throughout
the entire night to record any fireballs over the Plain.
Combined with some clever mathematics, they were then
able to calculate the original orbit of the object and where
to search for the meteorite on the ground.
And, the ability to track meteorites back to
their asteroid home also means it is an incredibly cheap way
of sampling that asteroid, rather than conducting an expensive
space mission, the astronomers said.
Team member and CSIRO Exploration & Mining scientist
Rob Hough said the search for the meteorite was helped by the
fact the Nullarbor Plain is marked by white limestone rocks.
"So a dark meteorite on the white surface is easier to
find, however it`s very tiny, so the discovery is still really
quite amazing. This particular meteorite is very interesting
because of its rarity. It is an achondrite -- a basalt -- with
a composition that suggest an asteroid from the inner asteroid
belt," Hough said.
According to the astronomers, the all sky cam network
had been an extremely successful project and had spotted many
fireballs.
"The Plain is very difficult place to have technology
like the cameras and the fieldwork to find the meteorite is
not trivial. The logistics are a really important aspect of a
project like this and it takes a lot of planning to make it
work," he said.
Bureau Report
