After being lost for 36 years, the lunar rover Lunokhod 1, has been rediscovered by astronomers using laser pulses. Using data from NASA's Lunar Reconnaissance Orbiter (LRO), Associate Professor Tom Murphy at the University of California, San Diego, and his colleagues worked out its position to within a few centimetres, reports
Lunokhod 1 was launched from the Baikonur Cosmodrome aboard the then Soviet Union''s Luna 17 mission, landing on the Moon on the 17 November 1970.
The rover is about the size of a small car and looks like a tin bathtub with a lid. It travelled about 10 kilometres along the lunar landscape sending back tens of thousands of images and soil analyses from over 500 sites.
After it stopped working, scientists continued to bounce laser light off an array of French-built mirrors located on the rover''s back. The last recorded return signal was in May 1974, but the exact details of its position were never fully locked down.
The more reflectors you have the more accurately you can measure the position of the Moon, so researchers enlisted the help of the LRO to search for Lunokhod 1.
One month later, Murphy's team fired a laser from the Apache Point Observatory in New Mexico in that direction and detected a return.
"We found to our surprise that Lunokhod 1 is a much better reflector than its twin L2," they wrote.
The researchers said the Lunokhod 1 reflector is especially useful because it is closer to the Moon''s limb than any of the other reflectors. And unlike the Lunokhod 2 reflector, it can be used during the lunar day.
Their paper has been submitted ot the journal Icarus.