The 12 members of the winter 2005-2006 expedition
(Photo: Gordon Osinski)
In the wind-swept Miller Range of the Transantarctic
Mountains, 12 intrepid scientists have come in search of meteorites, rocks that have fallen to Earth from outer space. Among them is Dr. Gordon Osinski of the Canadian Space Agency.
For two months, he joins the Antarctic Search for Meteorites Program (ANSMET), led by Ralph Harvey from Case Western Reserve University and funded by the U.S. National Science Foundation and NASA. This is Osinski's second trip to the Antarctic; he was part of the team that found a Martian meteorite in 2003.
Antarctica is one of the best places on Earth to find meteorites. On expanses of ancient, blue glacial ice where there's no permanent snow cover, almost any rock the team finds is likely to be a meteorite. In some places, concentrations of meteorites have built up over thousands of years, deposited by the continental ice sheet.
Gordon Osinski shows off a meteorite with a shiny fusion crust, formed as it passed through the Earth's atmosphere
(Photo: Gordon Osinski)
Patches of blue glacial ice in the Miller Range are a prime hunting ground for meteorites
(Photo: G. Osinski)
Another search begins
On November 19, 2005, the search team gathered in Christchurch, New Zealand for the 45-day search.
They were able to pack their gear and learn how to operate their equipment in extreme cold weather during
an overnight training session; they ensured it was working properly. Each team member was outfitted with rescue equipment because they could be stuck inside the tent for days during howling winds of 60
km an hour or more.
ANSMET camp on an ice field in
the Antarctic
(Photo: G.
Osinski)
Gordon Osinski (right) inspects a large fusion-crusted meteorite (Photo:
G. Osinski)
The meteorites found in the Antarctic could have fallen to Earth as long as 100,000 years ago. And for those that are recovered, another journey awaits. The meteorites are placed untouched in a sealed bag and kept frozen en route to the Johnson Space Center in Houston, Texas. They are then classified and made available to scientists around the world.
Reading rocks for evidence of water on Mars
Since 1976, the ANSMET program has collected more than 15,000 meteorites from the Antarctic. Most of the rocks are pieces of asteroids, while a few originated on the Moon and Mars. The collection has led to a better understanding of the history and composition of the solar system. For example, the abundance of meteorites that are chemically very similar to the Sun offers more opportunities to study what conditions were present during the formation of the solar
nebula—the large cloud of gas and dust from which the Sun and planets formed 4.6 billion years ago.
The 2003 ANSMET field team with
its 500th meteorite
(Photo: G. Osinski)
Gordon Osinski on the 2003 Antarctic meteorite search
(Photo: G. Osinski)
Osinski will also start a new project. "It involves studying how meteorites and Earth rocks weather in the cold, dry Antarctic
climate, which is similar in some respects to Mars," he says. "We'll be documenting the types of rocks we find and analyzing what processes are responsible for creating various textures in them. We can then use our findings to help analyze images sent back to Earth by robotic missions to Mars. Ultimately, our goal is to try to find evidence that there was once liquid water on
Mars."
