The Mars rover Curiosity has found something — something
noteworthy, in a pinch of Martian sand. But what is it? The
scientists working on the mission who know are not saying.
Outside that team, lots of people are guessing. The intrigue
started last week, when John Grotzinger, the Mars mission’s
project scientist, told National Public Radio: “This data is
going to be one for the history books. It’s looking really
good." And then he declined to say anything more. Fossils?
Living microbial Martians? Maybe the carbon-based molecules
known as organics, which are the building blocks of life? That
so much excitement could be set off by a passing hint reflects
the enduring fascination of both scientists and nonscientists
with Mars. “It could be all kinds of things," said Peter Smith,
a planetary scientist at the University of Arizona who was the
principal investigator for NASA’s earlier Phoenix Mars mission
but is not involved with Curiosity. “If it’s historic, I think
it’s organics. That would be historic in my boo