Meet Yeti, a faithful rover of the robotic kind that sniffs out dangerous crevasses for convoys crossing the glaciers of Antarctica and Greenland, explores ice caves on an active volcano and finds old buildings buried under the polar ice.

This southern summer, Yeti trundled ahead of the bright orange tractors that deliver supplies to research outposts throughout Antarctica. Towing a ground-penetrating radar, the rover alerts drivers to hidden breaks in the ice. Snow often bridges the fissures, obscuring hazards, but the little robot is light enough (150 pounds, or 68 kilograms) to ford the breaks if not stopped in time.

"It's not likely to fall through, and there's no danger to the robot except losing the robot," said Laura Ray, an engineer at Dartmouth in Hanover, N.H., who led the robot's development.

... The Yeti robot, conceived and built by Dartmouth engineering students, cost about $25,000, Ray said. The Mars Curiosity Rover cost $2.5 billion to design, construct and land on another planet.

Constructed from off-the-shelf parts and batteries sturdy enough for very low temperatures, the rover has been a popular addition to the United States polar science program.

"It's always in the field or in transit," Ray said. "I would love to make a second or a third robot, or transfer this technology to a company so we can get them into more hands."