Nomad's quest

 作者:陈穗     |      日期:2019-02-27 08:08:00
By Jeff Hecht WHILE the Sojourner rover crawled over a few metres of the Martian landscape, a larger robot called Nomad was making an epic journey across the barren Atacama desert in Chile. The four-wheeled Nomad clocked up 215 kilometres in six weeks of tests designed to discover how robotic vehicles might explore the Moon and Mars. Nomad not only succeeded in finding meteorites planted in the desert, but it also made a real discovery—a type of rock not recorded in Chile before, says Nathalie Cabrol of the NASA Ames Research Center in California. Measuring 2.4 metres across and weighing 250 kilograms, Nomad dwarfs the Martian rover. It was built by William Whittaker and his team at Carnegie Mellon University, Pittsburgh. Next year, NASA plans to put Nomad to work looking for meteorites on the Antarctic ice. The project has cost $1.6 million so far. The robot identified one meteorite placed on the desert surface, and recognised two other unusual rocks that were not meteorites. Nomad also spotted two out of three buried meteorites, with its magnetometer. The discovery of the new type of rock was good news for the team: this is precisely the sort of task NASA wants robots to perform on Mars. The team at “mission control”, thousands of kilometres away, saw that the rock was unusual—and might contain fossils— from data provided by Nomad’s sensors. Team members in Chile retrieved it and sent it to Ames. Tests showed that the rock was formed more than 150 million years ago in the ocean, but did not reveal any definitive traces of life. Nomad carries a camera that gives a full 360° view of its surroundings. “That’s exactly what geologists need to understand the area,