People with a general idea of how space works may assume everything we left on the Moon from the US trips in the late 60’s and early 70’s should remain exactly the way it is, footprints and all, given a lack of interference. This isn’t entirely true. Future visitors to the Moon may see an odd white handkerchief on a pole instead of the Stars and Stripes.
Why? Well, you may have noticed when you keep an object near a window for several months, its colors eventually start getting bleached out by the sun’s UV rays. Now imagine how much quicker that would happen without an ozone layer or any of the other protections the Earth’s atmosphere provides. Analysis: the flags on the moon are white now.
And as lunar scientist Paul D. Spudis points out in his article on the Air and Space Museum website, circumstances will get worse: “For forty-odd years, the flags have been exposed to the full fury of the Moon’s environment – alternating 14 days of searing sunlight and 100° C heat with 14 days of numbing-cold -150° C darkness.” He points out, “Some of them may even have begun to physically disintegrate under the intense flux.”
This all means by the time anybody can gather up the money and manpower to revisit the Moon, the US flags may no longer be there. You’d think the $5.50 NASA spent on the nylon (accurate) would hold up.