American physicists locate long lost Soviet Union reflector on Moon

SAN DIEGO - A team of physicists, led by a University of California professor, has pinpointed the location of a long lost light reflector left on the Moon by the Soviet Union nearly 40 years ago, which many scientists had unsuccessfully searched for and never expected would be found.

The French-built laser reflector was sent aboard the unmanned Luna 17 mission, which landed on the Moon on November 17, 1970, releasing a robotic rover that roamed the lunar surface and carried the missing laser reflector.

The Soviet lander and its rover, called Lunokhod 1, were last heard from on September 14, 1971.

“No one had seen the reflector since 1971,” The American Astronomical Society quoted Tom Murphy, Associate Professor of Physics at University of California, San Diego, as saying.

Murphy said his team had occasionally looked for the Lunokhod 1 reflector over the last two years, but faced tall odds against finding it until recently.

The breakthrough came last month when the high-resolution camera on NASA’s Lunar Reconnaissance Orbiter, or LRO, obtained images of the landing site, he added.

The camera team, led by Mark Robinson at Arizona State University, identified the rover as a sunlit speck on the image- miles from where Murphy and his team had been searching.

“It turns out we were searching around a position miles from the rover. We could only search one football-field-sized region at a time. The recent images from LRO, together with laser altimetry of the surface, provided coordinates within 100 meters, and then we were in business and only had to wait for time on the telescope in good observing conditions,” Murphy said.

On April 22, his team sent pulses of laser light from the 3.5 meter telescope at the Apache Point Observatory in New Mexico, zeroing in on the target coordinates provided by the LRO images.

Murphy, together with Russet McMillan of the Apache Point Observatory in Sunspot, NM, and UCSD Physics graduate student Eric Michelsen found the long lost Lunokhod 1 reflector and pinpointed its distance from Earth to within one centimeter.

They then made a second observation less than 30 minutes later that allowed the team to triangulate the reflector’s latitude and longitude on the Moon, in other words its exact spot on the Moon, to within 10 meters.

In the coming months, he estimates it will be possible to establish the reflector’s coordinates to better than one-centimeter precision. (ANI)