Planetary scientist David Grinspoon discussed the discoveries and data that have been coming back from the Huygens Probe which landed on Titan. In many ways, Titan is like an "alternate reality" Earth with its weather and geology resembling ours, he said. But instead of water, there are rains of liquid methane which sets up a hydrological dynamic. Though it's very cold on Titan (the sun would only appear 1/10th as large) it's possible that some type of life form that thrives on methane or other substances might exist there, he theorized. Going deeper into Titan's surface it would be warmer and there could be liquid water mixed with ammonia there, he added.

"I think there could be life on Venus," such as bacteria that evolved to live in the clouds there, Grinspoon speculated.He was enthusiastic about the renewed interest in our moon and the new photos coming in from ESA's SMART-1. "We've only scratched the surface" and there are many mysteries to yet uncover on our moon, he said.He also admitted that "it's quite possible there could be alien artifacts in the solar system."

Grinspoon said he is now involved in developing a new Martian rover for NASA that will launch in 2009. He's working on building an instrument called RAD (radiation assessment detector) which will measure the radiation environment on Mars.