So much for “leave only footprints”
Getting to the Moon isn’t easy, which means coming back from the Moon isn’t much easier. With a few, mostly sentimental exceptions, we’ve just decided that it isn’t worth the trouble to pick up after our various visits to the Earth’s primary natural satellite.
With any mission, bringing cargo home means heavier spacecraft that requires more fuel to move (which is, in turn, heavier still.) With this in mind, NASA planners never really considered bringing home non-essential items, such as disposable food storage bags, wet wipes, and of course human waste. Even more durable goods weren’t worth the risk of complicating the return trip: TV cameras, golf balls, hammers, and the famous moon buggy all remain where we left them.
Some items were left for other, more symbolic purposes. American flags (now bleached white by UV light), a patch from the ill-fated Apollo 1 mission, and a silicon disc with greetings from world leaders were purposely left, as sort of reverse-souvenirs. One of the more touching items are the cremated remains of planetary geologist Eugene Shoemaker, who was unable to visit the Moon in his lifetime. It remains to be seen if these will be recovered by future, lunar archaeologists or discovered by some other life entirely, but efforts were clearly made to make sure we left a better calling card than just backpacks, boots and hygiene kits.
Beyond these items are around 70 spacecraft, mostly from unmanned missions. These craft were, again, never intended to return to earth, instead transmitting their scientific measurements electromagnetically back to Earth.
Estimates put the total collection at nearly 400,000 lbs of gear on the Moon, and chances are that total will grow further still before we even consider the costs of cleaning up. At least there’s no wild life to worry about.
Source: The Trash We've Left on the Moon by Megan Garber, the Atlantic