Leave No Trace
It's the most iconic footprint in the history of the human race, and every time I look at it, I think about how permanent a scar has been left on a pristine landscape. Left behind in 1969, that footprint is almost certainly still there, nearly identical to its original impression. There is erosion on the Moon, but it exists on a millennial scale, as solar wind and meteoroid bombardment slowly smooth away such imperfections. Barring impact with a huge meteor, this footprint, and the many hundreds more like it, not to mention the tire tracks left by the lunar rover, will still be there long after humankind has forgotten who put them there. If you've had anything to do with Scouting lately, or visited a National Park, or even been to Burning Man, you've encountered the words "Leave no trace." It's an ethical approach to outdoor recreation that has its roots in the environmental movement of the 1960s. I didn't hear the words until about 2003, when I was tr...