Tranquility Base (Apollo 11 landing site)

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The Apollo 11 landing site, on the southwestern Mare Tranquillitatis. Eagle set down here on 20 July 1969. The descent stage, the Passive Seismic Experiment package, the Laser Ranging Retroreflector, a United States flag, discarded equipment and the crews' bootprints all remain, imaged from orbit by the Lunar Reconnaissance Orbiter Camera since 2009 — the LROC data give the descent stage's position as 0.67408° N, 23.47297° E in the IAU lunar reference frame. The retroreflector is still ranged by laser from Earth, measuring the Earth–Moon distance to millimetre precision more than half a century later. The site was chosen for flatness, good Lunar Orbiter mapping coverage, an approach path clear of rough terrain, and a low-energy trajectory from an equatorial parking orbit.