I’ve just finished reading about how researchers have concluded that Mars was never warm based on analysis of a meteor–found on earth. More distantly you’ll remember that they were debating whether a fossil of a living organism had been found in a martian meteor found in Antarctica. My question: How do they know these meteors came from Mars? Are they labeled? Have they found meteors from other planets that they recognize? Why waste all this money and time on the space program if there are rocks from these planets just lying around earth? –Kent, Birmingham, Alabama
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The rocks were found on earth, Kent, so they’re meteorites, not meteors. (Meteors are space rocks that fry in the atmosphere; meteorites are the remnants that make it all the way down.) Once you get that straight, try chewing on this: Scientists think the martian meteorites came from Mars because–I realize the nontechnical mind won’t find this entirely persuasive–they couldn’t plausibly have come from anywhere else.
Convinced? McSween’s fellow rock jocks initially didn’t buy it either. But then other researchers analyzed the minute bubbles trapped in a shergottite meteorite, which presumably were a trace of the atmosphere of the rock’s home planet. The noble gases in the bubbles (argon and such, which being noble don’t change over time and so are a sort of planetary fingerprint) precisely matched those in the martian atmosphere as sampled not long before by the Viking landers.
Art accompanying story in printed newspaper (not available in this archive): illustration/Carl Kock.
