New analysis suggests that two faint signals thought to be from the Mars Polar Lander were likely terrestrial in origin, a Stanford University scientist said Tuesday. A 150-foot (46-meter) radio antenna at the Northern California university picked up the weak signals on December 18 and January 4, reviving hopes at the time that the errant Polar Lander remained alive. The $165 million spacecraft vanished December 3 after plunging into the martian atmosphere at the start of what was to have been a 90-day mission.