據《科學》雜志報道，蘇聯的月球車40年前在月球表面留下了激光反射器，雖然經過多年的搜尋科學家始終沒有發現激光反射器的蹤跡。

　　4月22日，一組物理學家終于發現了來自反射器的微弱閃光。NASA的月球偵察軌道器在這項發現中起了重要作用，它上個月拍攝了據報導蘇聯登月車駛過的地區的衛星圖像。加州大學圣迭戈分校的Tom Murphy領導的團隊分析了地圖，終于發現了反射器的位置。利用新墨西哥州Apache Point天文臺3.5米口徑望遠鏡發射出的一束激光，研究人員立即測量出地球到反射器的距離，誤差在1厘米內。

In 1970 the Soviet Union put a laser reflector on the moon, carried by a rover. A few months later, it disappeared. Some speculated that the rover had fallen into a crater or parked in such a way as to render the reflector inaccessible. Now, after 40 years on the lunar surface, the reflector has been found.

A team at U.C. San Diego had been searching for it. Earlier this year, NASA’s Lunar Reconnaissance Orbiter camera provided images of the original landing area. A sunlit speck, miles from where the team was looking, turned out to be the rover and reflector. The San Diego team was quickly able to pinpoint the reflector’s location to within 10 meters.

Scientists send laser pulses to the moon and measure signals that bounce back from three reflectors left by Apollo astronauts, along with another Soviet one. This information helps track the moon’s position and orbit. And the researchers say that the rediscovered Russian reflector is particularly useful for studying the moon’s liquid core and testing ideas about gravity. Says team leader Tom Murphy of the reflector, “It’s got a lot to say after almost 40 years of silence.”

—Cynthia Graber