Meet Nomad, a clever robot that is sweeping the frozen landscape of Antarctica in search of meteorites.

It may have the appearance of beach buggy, but this machine represents a significant step forward in robotics and could pave the way to a new kind of mission to Mars and the Moon.

Nomad has been developed by researchers from Carnegie Mellon University's Robotics Institute, with funding from Nasa. The four-wheeled vehicle will autonomously search for meteorites and classify them with scientific instruments contained in its manipulator arm.

Its current expedition, just underway, marks the first time a robot has been used to discover extraterrestrial material that has fallen to Earth.

"Until now, explorative robots have taken pictures, gathered data and returned what they viewed to scientists who made judgements and decisions," says Nomad's project director, Professor Red Whittaker. "This time, Nomad will make its own judgements and inferences about the rocks that it encounters."

Mars meteorite

The robot is spending the next few weeks trundling around Elephant Moraine, a remote area in eastern Antarctica, 260 kilometres (160 miles) northwest of the US base at McMurdo Station.

Elephant Moraine is regarded as one of the more important sites for meteorite discovery, with thousands of specimens already recovered during previous expeditions, including the first meteorite identified as definitely being from Mars. Nomad's expedition is taking place near an area last searched in 1979.

Nomad has been programmed to move up and down a search area in much the same way as we would operate a lawn mower.

It has stereo cameras to give it a sense of the surroundings as it hunts for rocks distinguished by their dark colour against the white ice background. A high-resolution camera is used to zoom in on interesting specimens. A spectrometer then analyses the light reflected off a particular rock to determine its composition and whether it is a likely meteorite or not. A metal detector will pick up any iron content, an important component of some space rocks.

If Nomad thinks a specimen is a meteorite, it will radio the object's exact location to the researchers using co-ordinates calculated by the satellite-based Global Positioning System. The project team can then pick up the rock at a later time.

Breakthrough technologies

As Nomad explores an area, it must choose which rocks to examine and in what order. The robot has to decide whether it should drive, use its arm or employ both capabilities to reach its goal.

"This expedition will showcase the ability of a robot to discover meteorites, distinguish them from surrounding rocks and do it in an autonomous, self-reliant, self-contained manner," says Professor Whittaker.

"The breakthrough technologies are robotic classification and search. Humans classify every time they sort pennies from nickels, and they search every time they lose their car keys. But these are new skills for robots."

This is Nomad's fourth expedition overall, but the first on which it is expected to move and analyse specimens completely on its own. Previous outings, in Antarctica and Chile's Atacama Desert, have been used only to test systems.

If the Elephant Moraine expedition succeeds, the project scientists hope the technology will be picked up by Nasa for future missions to other worlds.

Nomad's expedition can be followed on Carnegie Mellon's interactive website known as the Big Signal Project.