Astronomy Picture of the Day

Explanation: It may look like some sort of cute alien robot, but it was created here on Earth, launched to the Moon in 1970, and now reflects laser light in a scientifically useful way. On November 17, 1970 the Soviet Luna 17 spacecraft landed the first roving remote-controlled robot on the Moon. Known as Lunokhod 1, it weighed just under 2,000 pounds and was designed to operate for 90 days while guided in real-time by a five person team near Moscow, USSR. Lunokhod 1 toured the lunar Sea of Rains (Mare Imbrium) for 11 months in one of the greatest successes of the Soviet lunar exploration program. This Lunokhod's operations officially ceased in 1971. Earlier this year, however, the position of the rover was recovered by NASA's moon-orbiting Lunar Reconnaissance Orbiter. Given that position, laser pulses from Earth were successfully bounced off the old robot's reflector. Bouncing laser pulses off of this and other lunar reflectors could yield range data to the moon accurate enough to track millimeter-sized deviations in the Moon's orbit, effectively probing lunar composition and testing gravitational theories.