Narrator: This is Science Today. Recent images of dust storms on Mars are helping astronomers study its changing surface and weather conditions and prepare for NASA's mission to send rovers to explore the planet's surface in 2004. Meanwhile, biochemist Mark Thiemens of the University of California, San Diego has developed a way to chemically interpret the make-up of Martian meteorites. This can help scientists unravel the history of the red planet - including signs of past life.
Thiemens: The meteorites we get and analyze have come from different times in Martian history, so by looking at those, one has sort of a snapshot of what happened over time in the Martian atmosphere.
Narrator: Thiemens says the Mars exploration rovers will provide researchers with new samples.
Thiemens: We can certainly continue in analysis of other of these Martian meteorites that come from different times, but we really need return samples - carefully controlled and from areas where you might really get at the information you need. That you can go down to the precision and determine where your samples come from, rather than random events.
Science Today, I'm Larissa Branin.