Lunokhod 1 was a robot type of rover that the Soviets landed on the moon in 197o thanks to the Luna 17 lander.

Using solar panels during the day and a radioisotope powered heater at night, the rover was able to explore the moon for 322 Earth days. From NASA:

This first successful Soviet rover operated for 11 lunar days, the equivalent of 322 Earth days. It traveled more than 10 km across the lunar surface, during which it transmitted more than 20,000 TV images and 206 high-resolution panoramas, performed 25 soil analyses with its spectrometer, and used a penetrometer to test the soil’s mechanical characteristics at more than 500 locations.

After losing contact with the rover, the project was terminated on October 4, 1971.

A team of researchers from the UCSD (University of California at San Diego) have been using reflective space junk left on the moon to show deviations in Einstein’s theory of relativity. This is accomplished by measuring the shape of the lunar orbit using light pulses, distance and time. The team leader is Tom Murphy, associate professor of physics at UCSD and they have been searching for Lunokhod 1 for many years.

Tom states:

We quickly verified the signal to be real and found it to be surprisingly bright: at least five times brighter than the other Soviet reflector, on the Lunokhod 2 rover, to which we routinely send laser pulses, Murphy said. The best signal we’ve seen from Lunokhod 2 in several years of effort is 750 return photons, but we got about 2,000 photons from Lunokhod 1 on our first try. It’s got a lot to say after almost 40 years of silence.

Link via (The Register)