Narrator: This is Science Today. NASA's plan to launch a robotic Mars rover in 2003, will mark the longest scientific exploration ever undertaken across the Martian surface. Biochemist Mark Thiemens, of the University of California, San Diego, developed a new way to interpret the make-up of martian meteorites and is looking forward to studying 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.
Narrator: Thiemens and his group developed a way to use isotopes to fingerprint chemical processes in Martian meteorites, which 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: For Science Today, I'm Larissa Branin.