The scientific results from the Mars rovers and Phoenixprobe, which are poised to reveal provocative new clues in the tantalizing search for water and life on the Red Planet.

More than four years after they landed on Mars, NASA's twin robot explorers, Spirit and Opportunity , have lasted 16 times longer and driven 20 times farther than expected. Along the way, they've endured the worst Martian storm ever recorded and survived near-fatal software glitches, a broken wheel and hair-raising climbs and descents on steep slopes. And since May 25, 2008, they've had new company on the red planet: NASA's Phoenix probe, which dramatically "tasted" water ice on the planet in July. NOVA "Is There Life on Mars?" showcases the latest scientific results from the rovers and Phoenix , which are poised to reveal provocative new clues in the tantalizing search for water and life on the Red Planet.