The footprints left by Apollo astronauts on the Moon will last approximately 100 million years

The Moon has no atmosphere, no wind, no rain, and no significant erosion processes. The footprints left by Neil Armstrong, Buzz Aldrin, and subsequent Apollo astronauts in the lunar regolith (dust) will remain largely intact for tens of millions of years. The only forces that will eventually erode them are tiny micrometeorite impacts and cosmic rays, processes so slow that the prints are expected to survive for 10-100 million years. The Apollo equipment left on the surface will similarly last almost indefinitely.