Asked by: Steve Cameron, by email
It has been estimated that there are more than 180 tonnes of man-made material on the Moon, ranging from bags of human body waste to crashed spacecraft. But there is very little to affect this material – no wind, pollution or water to erode, rust, dissolve or abrade it – although the action of sunlight, particularly UV radiation, has probably already bleached the US flags left there by the Apollo astronauts. While the constant bombardment by energetic micrometeorites is likely to gradually erode this material over time, current research suggests it could survive for up to 100 million years!
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