I wondered why everyone kept clustering around Tony Irving, of the University of Washington at Seattle. Then I realized: if you’re the guy holding a moon rock at a lunar science conference, you’re pretty popular. Here’s Tony with his 600-gram, 1-centimetre thick slice of the moon, taken from the 2nd largest lunar meteorite ever, an 11.5 kilo monster found in Morocco last summer. That’s just shy of “Big Muley,” an 11.7 kilo sample that was the biggest returned by the Apollo astronauts.

Meteorite hunting has become big business in the dry deserts of northwest Africa and the Arabian peninsula. You can buy moon rocks on eBay, where little flakes sell for hundreds and thousands of dollars. Randy Korotev, who maintains a wonderful lunar meteorite Web site at Washington University in St. Louis, estimates that, per gram, you pay more for moon than you would for diamond or gold.

Assuming a bargain basement price of $1,000 per gram, Tony’s slab would be worth half a million dollars, and the 11.5 kilo monster it came from would be worth more than $10 million. But Tony insists: “It’s a scientific treasure, not a financial treasure.”

The rocks are important because they represent a wider distribution of the types of rocks that exist on the moon. The Apollo missions only retrieved rocks from a few specific areas. Whereas the 56 known lunar meteorites, which result from random impacts, sample a far greater area. This one, Tony says, comes from highlands on the lunar far side. He says it’s an important rock because it contains bits of iron nickel metal that are exotic to the moon.

When I spoke with him, Tony was expecting, that afternoon, lab results that would estimate the period of time the rock had sat in the Moroccan desert. Then he plans to do another test to find out how long the rock spent in space. He already can guess the rough age of the rock itself: something on the order of 4 billion years, when the moon became a cold, dead place.

But this cold, dead rock was arousing some lively discussions. As Irving walked around, many stopped to stare at the sample sealed within the vacuum of the Captain Nemo, submarine-style chamber. “Some people say it looks like a map of France,” he says.