An expert from the National Science Foundation's Antarctic Search for Meteorites (ANSMET) program, who collected the specimens after Nomad identified them in the field, has concluded that five of the seven are meteorites.

The other two raise enough questions about their composition to merit further study. ANSMET is housed at Case Western Reserve University in Cleveland.

Meteorites are curated at the Johnson Space Flight Center in Houston and made available to scientists around the world.

"Nomad has found and correctly classified three indigenous meteorites in-situ," said Dimitrios Apostolopolous, a systems scientist at Carnegie Mellon's Robotics Institute and project manager of the Robotic Antarctic Meteorite Search initiative.

"The robot correctly classified three other indigenous meteorites and misclassified one as terrestrial rock. Nomad achieved these results autonomously and without any prior knowledge about the samples."

Most of the chondrites that Nomad found are relatively common types, composed mainly of rock with small metallic infusions that probably originated from asteroids.

One achondrite meteorite which Nomad classified as interesting is so rare that the robot didn't have the data in its base to make a determination.

The robot made its discoveries at Elephant Moraine in eastern Antarctica, 160 miles northwest of the United States base at McMurdo Station.

The area is an important site for meteorite discovery, with nearly 2,000 specimens recovered during seven previous visits, including the first meteorite identified as definitely being from Mars.

This expedition took place in an area that was last searched by ANSMET scientists in 1979.

Nomad's expedition and the discoveries it has made are significant because it marks the first time a robot, relying on sensors and artificial intelligence, has been able to find a meteorite lying on the ice and distinguish it from ordinary rocks in the area.

The first discovery came on Jan. 22, as the robot traveled over an area the size of a football field in patterns similar to those a person would make when mowing a lawn.

The search site contained false meteorite look-alikes, sometimes called "meteorwrongs," as well as typical Antarctic rocks.

When Nomad encounters a promising rock, it deploys its manipulator arm containing a high-resolution camera and a spectrometer to gather visual images and spectroscopic data upon which to determine a specimen's composition.

When Nomad found its first meteorite, it had already completed 350 meters of linear searches and had examined seven other rocks.

ROBOTS DO ANTARCTICA - PART TWO