GENEVA (AP) -- A fist-sized meteorite, one of only 18 rocks on Earth known to have come from Mars, has been found by Swiss scientists in the Oman desert -- a prize discovery that could help determine if the planet ever sustained life.
Scientists at the University of Bern announced the find Friday and said they are just beginning to examine the meteorite. Most of the other 17 Martian rocks have been snapped up by collectors, they said, so few are fully available for study.
``I suspected from the beginning that it was from Mars,'' said Marc Hauser, a geologist who found the gray, ridged specimen during a collecting excursion in January. ``The color was different and, above all, it wasn't magnetic.''
Initial conclusions could take several months.
Unusually large pockets inside the half-pound rock could provide evidence about life that is far more conclusive than American suggestions about possible fossils on an earlier meteorite found in Antarctica, Hauser told The Associated Press.
The new meteorite was named Sayh al Uhaymir 094 after the region of desert where the team found it and more than 180 other meteorites. The team, in a statement, said they were certain it would contribute to rapidly growing knowledge of the planet.
Interest increased in 1996 after a Martian meteorite found near the South Pole, known as Allen Hills 84001, showed possible remnants of life. But such arguments ``are hardly taken as solid evidence today,'' the research team said.
Most earlier meteorites from Mars were found in the Antarctic before scientists turned their attention to deserts in recent years.
Hauser said X-rays of the new rock had shown a surprising number of hollow pockets inside that might contain gases or atmosphere. That could offer clues about both the meteorite's history and Mars itself.
The pockets have ``a much greater potential'' than the rest of the rock for containing evidence of life on Mars, Hauser said.
Most of the 180 meteorites found by the team were magnetic and looked distinctive, but the Martian rock looked more like rocks from Earth and was difficult for the team to recognize as a meteorite. The other meteorites also contained no minerals.
Hauser said the team believes the Martian meteorite is part of another one found earlier in the same area.
That first rock is in unknown private hands, as are most Martian meteorites because collectors are willing to pay $1,000 a gram for such treasures. But the team was able to obtain a small fragment of it for testing, Hauser said, and its makeup is practically identical.
The team said they and other scientists had determined their meteorite is from Mars by the nature of its minerals, measurements of its oxygen isotopes and its overall composition. They conducted analyses on both the entire rock and tiny fragments of it.
They said the rock had been formed from molten lava, similar to volcanic rocks on Earth.
Mars is the most Earth-like of all the solar system's planets, and evidence suggests both planets developed similarly during their first billion years -- the period when life first appeared on Earth.
The team said recent discoveries about life on Earth in extreme environments -- such as in very hot ocean springs or within porous rocks deep inside the planet's surface, support the theory that early Mars could have had environments suitable for life.
The rare Martian meteorites could be the only physical evidence available to scientists for at least 10 years, when a U.S. space probe might bring back 1.1 pounds of Martian samples ``at very high costs.''
Rocks from Mars start their journey toward Earth when a meteorite from elsewhere slams into the Martian surface, scattering rocks into space at high speed. They eventually make their way to Earth, sometimes after millions of years.
File Date: 6.15.01