It sounded like thunder. Then a farmer in Zagami, Nigeria, heard a loud thud in his field and found a shiny black rock. It turned out the rock, with a surface that looked like a burnt English muffin, had once been a part of Mars. It was a relatively rare 1962 discovery.
Scientists regularly comb the ice fields of Antarctica looking for tiny bits of rock that have survived the flaming flight through Earth's atmosphere. Of 20,000 recorded meteorites, only 12 are known to be of martian heritage. If you put all the Mars rocks on one scale, they would weigh only about 30 pounds. Most are in museums, which have agreed to a moratorium on the future sale or exchange of the rocks.
Tomorrow, however, three pieces of the Red Planet will be auctioned off by Guernsey's, a New York auction house. The owner, who wishes to remain anonymous, has placed a reserve, or minimum bid, of about $1 million on the lot, which comprises the three meteorites, each representing a separate entry into Earth. A portion of the proceeds will go to the American Cancer Society. Guernsey's president, Arlen Ettinger, expects the rocks to sell for $1.5 to $2 million.
This estimate for a few rocks is not as wild as it seems. In 1993, Sotheby's, another auction house, sold three small Russian moon rocks for $442,500. Sotheby's had estimated the rocks would sell for $30,000 to $50,000. In fact, that entire auction, which included space capsules, brought in $6.8 million.
The seller of the Mars rocks is capitalizing on a sudden price surge in martian rocks. "Until recently they were not that expensive ... but they have quadrupled in price over the last six months," says Simon Clemett, a post-doctoral student at Stanford University in Palo Alto, Calif. and a Mars rock researcher.
Behind the surge is an increasing interest in the fourth planet from the sun. In early November, NASA launched a satellite that will orbit and map Mars. And earlier this year, scientists said a martian rock showed signs that microbial life once existed on the planet. This sparked Page 1 stories. In 2003, NASA hopes to culminate its studies by retrieving about a pound of martian rock. The cost: a projected $8 billion.
The mania is moving some entrepreneurs into warp speed to look for more martian rocks. Robert Haag, a Tucson, Ariz., collector is working with a village in Egypt to search for pieces of a Mars meteorite that landed nearby. "This is incredibly labor intensive, but if you can get them looking with the reward of big cash, there's a chance," he says.
That chance, however, may be pretty small. There is nothing particularly striking about rocks from Mars. "If I found one in my garden, I would be likely to throw it away," says Richard Zare, a chemistry professor at Stanford University and a Mars meteorite expert.
In fact, in order to assure buyers that these particular rocks are from Mars, Guernsey's has turned to Robert Hutchison, one of the foremost experts on martian rocks and head of the Cosmic Meteorology Department at the Natural History Museum in London.
Scientists normally find meteorites in the Antarctic ice beds. "There is no way you would expect a rock to be in the ice, so if it's there it came down from above," says Mr. Zare.
Scientists were able to determine that some of these meteorites came from Mars after the Viking mission sent back soil data in 1976. When they reexamined some of the meteorites, they had the same mineralogy.
One of the meteorites offered for sale - the one that landed in the Nigerian field - is similar in chemical and mineralogical makeup to another meteorite that fell in Shergotty, India 100 years earlier. A "Shergotite" meteorite from Antarctica is the rock that contained possible traces of microbial life. (Meteorites have very wide geographic distribution because they break up as they enters Earth's atmosphere. Scientists name meteorites for the first place they are discovered. Thus, a meteorite found in Antarctica could be named after the first discovery of the meteorite in India.)
Mr. Clemett says it is doubtful that the Shergotite rock being auctioned would have much scientific value. "It's too heavily contaminated and been around too long," he explains. Most of the scientific samples recovered from Antarctica are kept in nitrogen to prevent oxidation.
Zare, however, says the rock, which weighs a whopping 420 grams (1.1 lbs.), would be interesting to examine for its isotope ratios. These don't change with normal handling. And according to a study conducted by a team of British scientists, they may hold signs of past microbial life.
Mr. Haag, who claims one of the largest meteorite collections in the country, also owns the largest Mars meteorite, a seven-pound hunk discovered in Nigeria. He values it at $10 million. Even before the auction, it seems the price of Mars rocks is going to the moon.