All articles tagged with #retroreflectors
Apollo-era lunar retroreflectors remain functional, allowing Earth-based lasers to measure the Earth–Moon distance to millimeter precision. The Moon is slowly drifting away at about 3.8 cm/year due to tidal friction, enabling stringent tests of general relativity, with next-generation reflectors and DLLR aiming to improve measurements further.
Humans have dumped a surprising amount of material on the Moon—from rocket stages and rovers to sentimental keepsakes (an Apollo 16 family photo, Gene Shoemaker’s ashes, and goodwill messages from 73 nations), commemorative patches, a rumored Moon Museum ceramic wafer, a falcon feather, and even 96 bags of human waste. NASA’s 2012 list tallies about 400,000 pounds of Apollo‑era debris, with additional gear from other programs; retroreflectors remain on the surface for millimeter‑precision distance measurements. As new missions resume lunar exploration and imaging improves, lunar debris management could become a hot topic for future explorers.