PITTSBURGH -- Carnegie Mellon University's Nomad robot, which conducted an autonomous search for meteorites in Antarctica from Jan. 20-30, has successfully completed its mission, examining more than 100 indigenous rocks, studying about 50 in detail and classifying seven specimens as meteorites.
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.
With the help of machine learning and statistical techniques, Nomad puts a numerical value on its confidence that a rock is or is not of extraterrestrial origin. It classified its first meteorite with a confidence rating 2.5 times higher than any other rock it examined. The more rocks it studied, the higher its confidence rating went in making its determinations.
Six researchers from Carnegie Mellon's Robotics Institute and ANSMET team member John Schutt accompanied Nomad to Elephant Moraine. After Nomad located the meteorites, Schutt collected and gave them a temporary numerical label. "This is a small step for a robot and a big step for robot kind," said William L. "Red" Whittaker, principal investigator for the Robotic Search for Antarctic Meteorites initiative. "This marks the first discovery in the natural world by robotic machine intelligence and sets a precedent for a new class of robotic science on Earth and in space."
"Nomad's meteorite finds are a great achievement," said Apostolopoulos. "However, it had to gather still more data. During the last three days of the expedition, the robot was turned loose in an unscouted area to seek meteorites among high concentrations of terrestrial rocks mixed with snow and ice. Making more interpretations like this in the field enabled Nomad to prove its robustness. Further analysis of the field data will allow a solid scientific evaluation of the robot's abilities and can help set expectations for future generations of planetary rovers."
"With these finds, Nomad takes robotics beyond the typical concerns about nuts and bolts and into the universe of scientific inquiry," said Ralph Harvey, principal investigator for ANSMET. "We all dream of a future where robots can act and perhaps even think independently," he added. "Nomad has now taken the first steps along that path."
Nomad's expedition to Elephant Moraine is a collaborative effort between the Robotics Institute at Carnegie Mellon University and the National Science Foundation's (NSF) Antarctic Search for Meteorites program. It is being performed under the auspices of NSF's Office of Polar Programs.
The Nomad robot has been developed through research at Carnegie Mellon's Robotics Institute and is funded by grants from NASA's Surface Systems Thrust of the Cross Enterprise Technology Development and Space Telerobotics programs.
Experience Nomad's search for Antarctic meteorites at:
www.ri.cmu.edu/~meteorobot2000.
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