We drove the farthest winding roads of Sierra Madre to the base of Mt. Wilson, where we parked, crossed a bridge, over a babbling gully, and into the greenhouse of Antonin Bouchez. Antonin is a planetologist who divides his time between the observatories of Hawaii, Alaska, Arizona and California. In a few weeks, he is off to the Keck Observatory on the Big Island. Then, to San Jose for NASA, where he will spend 120 nights watching Io, a moon of Jupiter, and studying its volcanology.

"You can't actually see an eruption," he says, "I'll be looking for gray rings of sulfur, and watch how they disperse." Soon, we were passing through the Northern Mojave. Somewhere past Lancaster, Antonin pointed out a steep ledge, "The Garlock fault," he said, "was just discovered a few years ago."

Past Acton, we climbed a slight incline, dotted by new homes and billboards with fancy names for new developments. "This is the San Andreas Fault," Antonin said, and we stared out the window at the roadcut. It was contorted rock - swirled and shaken and molten and reshaped. Lily said, "I bet none of these people have a clue about what they're standing on."