Scientists say the chunks of space rock -- which come from asteroids or more rarely from the moon or Mars -- may hold the answers to questions about the solar system, the formation of Earth and how life began.

"It is kind-of like the ultimate detective story," said Thomas Wagner, National Science Foundation program director for Antarctic Geology and Geophysics.

Meteorites found on the southernmost continent are especially valuable because snow and ice have kept them in pristine condition.

"If we dropped a rock in North America, it is going to get rained on, it is going to get sun on it, and it is going to break down," Wagner said. "In Antarctica, that doesn't happen."

One question Antarctic meteorites already have answered is whether chunks of other planets or moons fall to Earth. Wagner said scientists once thought it couldn't happen, but five Martian meteorites and 15 lunar meteorites found in Antarctica's tundra now are housed at the Houston lab.

"Meteorites represent the crust, mantel and core of planets that were completely smashed to bits, so they are an important piece of information in understanding other planets," Wagner said.

In the sterile lab, workers cover their clothes, shoes, heads and hands in one room before stepping into another for an air shower to remove any dust or other particles. Once the air cuts off, scientists open another door leading to a room where meteorites await cataloguing and study. Nitrogen constantly flows over the meteorites to keep them dry and protected.

The latest 1,358 frozen Antarctic meteorites -- most the size of baseballs, golf balls or smaller -- arrived at the lab last month, bringing the collection to an impressive total of about 14,000.

Workers number and chip away a small piece of each new arrival to send to the Smithsonian, which catalogues the meteorites. The remainder of the sample remains at Johnson Space Center for at least five years. Photographs and a description of each meteorite are included in scientific catalogues aimed at drawing researchers to the lab.

"You can study a small sample in great detail and learn a lot," said Kevin Righter, the Space Center's Antarctic meteorite curator. "There is value in the small ones as well as the large. They all provide different information."

Big Lew's shape -- which resembles a spacecraft nose cone -- and large size makes the meteorite special, Righter said.

Big Lew was discovered in the 1980s in Antarctica's Lewis Cliffs ice field hundreds of thousands of years after it landed. It weighed so much, scientists had a hard time removing it from the frozen landscape.

NASA cosmic mineralogist Mike Zolensky was among the group who found the meteorite. He said Big Lew's shape is similar to some of the earliest meteorites discovered, which inspired the design for the space crafts in the 1950s. The shape is a result of the mass being heated and melted as it enters the Earth's atmosphere.

Scientists from Japan and Europe also have collected Antarctic meteorites, but the U.S. collection is the most well-organized, documented and studied, said lunar geochemist Randy Korotev, a professor at Washington University in St. Louis.

"For people like me, they are absolutely invaluable," Korotev said. "From my perspective, it is a national treasure."