Research Objectives:
Since 1976, ANSMET (the antarctic search for meteorites program) has recovered more than 14,000 meteorite specimens from locations along the Transantarctic Mountains. Antarctica is the world's premier meteorite hunting ground for two reasons:
+ First, although meteorites fall at random all over the globe, the likelihood of finding a meteorite is enhanced if the background material is plain and the accumulation rate of terrestrial sediment is low; this makes the East Antarctic Ice Sheet the perfect medium.
+ Second, along the margins of the sheet, iceflow is sometimes blocked by mountains, nunataks, and other obstructions; this exposes slow-moving or stagnant ice to the fierce katabatic winds, which can deflate the ice surface and expose a lag deposit of meteorites (a representative portion of those that were sprinkled throughout the volume of ice lost to the wind). When such a process continues for millennia, a spectacular concentration of meteorites can be unveiled.
The continued recovery of antarctic meteorites is of great value because they are the only currently available source of new, nonmicroscopic extraterrestrial material. As such, they provide essential "ground truth" about the composition of asteroids, planets, and other bodies of our solar system. ANSMET recovers samples from the asteroids, the Moon, and Mars for a tiny fraction of the cost of returning samples directly from these bodies.
During the 2004-2005 field season, ANSMET's main field party (eight people) will work at the LaPaz icefields, approximately 250 miles from Amundsen-Scott South Pole Station. A total of more than 1,000 meteorites have been recovered from the site during visits in 1991, 2002 and 2003. This year's field team will continue systematic searches of the icefields in an effort to recover a representative sample of the extraterrestrial material falling to Earth.
A second team consisting of four people will conduct high-level reconnaissance at a number of icefields throughout the mid-range of the Transantarctic Mountains, from the Zanefeldt Glacier in the south to Buckley Island in the north. This reconnaissance team will visit poorly known or previously unvisited icefields, recovering meteorites and identifying their potential for more detailed searches during future seasons.
