NASA renews hunt for Antarctic meteorites

NASA explores more cues to the primitive building block sof the solar system.

Washington, Nov 16: NASA has renewed its search for Antarctic meteorites to help learn more about the primitive building blocks of the solar system and answer questions about Earth's neighbours like the Moon and Mars.

NASA, the National Science Foundation (NSF) and the Smithsonian Institution (SI) recently renewed their agreement to search for, collect and curate Antarctic meteorites in a partnership known as Antarctic Search for Meteorites Programme (ANSMET).

The signing of this new joint agreement advances the programme for an additional decade, replacing an earlier agreement signed in 1980, NASA said.

"Antarctic meteorites are posing new questions about the formation and early history of our solar system. Some of these questions are spurring new exploration of the solar system by NASA missions," Smithsonian meteorite scientist Tim McCoy said.

Since the US began searching for meteorites in Antarctica in 1976, the ANSMET programme has collected more than 23,000 specimens, dramatically increasing the number of samples available for study from the Moon, Mars and asteroids.

Among them are the first meteorites discovered to come from the Moon and Mars, and the well-known ALH 84001 Martian meteorite, which helped renew interest in Mars exploration in the 1990s.

Meteorites are natural objects that fall to Earth from space and survive intact so they can be collected on the ground, or - in this case - on ice.

Antarctica provides a unique environment for the collection of meteorites, because the cold desert climate preserves meteorites for long periods of time, NASA said.

Movements of the ice sheets can concentrate meteorites in certain locations, making them relatively easy for scientists to find.

To search for meteorites, ANSMET deploys small field parties during the Antarctic summer (winter in the northern hemisphere). Even in summer conditions are harsh, with temperatures dropping to well below minus 18 degrees Celsius.

The ANSMET teams are flown to remote areas, where they live in tents on the ice and search for meteorites using snowmobiles or on foot.

Meteorites come from a variety of places in the solar system. Most meteorites originated on asteroids, which are remnants of the materials from which the planets formed.

Impacts of asteroids on the ancient Earth and other bodies in the solar system also may have played a significant role in the delivery of volatiles (like water) and organic molecules (such as amino acids) to planetary bodies, which, in turn, could have been important to the development of life.

A few meteorites originated on the Moon and Mars - blasted off the surfaces by large asteroid impacts and later falling to Earth.

The lunar meteorites may come from parts of the Moon not visited by astronauts in the 20th century, and they extend our knowledge of Earth's companion and how it formed.

Martian meteorites are humankind's only specimens of rocks known to be from another planet.

PTI