At any given moment, there are thousands of man-made objects orbirting our planet.Â Should an error occur and one come crashing back to Earth, we’re protected by our atmosphere.Â Our atmosphere will burn up most objects before they impact the ground, except for the largest of objects.
But that’s not the case with the moon.
With our atmospheric barrier, objects orbiting the moon could come crashing down to the lunar surface at 5,000 miles per hour, endanger astronauts on the surface or the historic landing site for the Apollo lunar missions.Â
To combat this problem, scientists at NASA are working to limit the number of artifical satellites placed into the moon’s orbit.
“NASA’s new robotic lunar exploration program and the eventual return of astronauts to the moon dictated that we address potential debris in lunar orbit,” explained Nicholas Johnson, Chief Scientist for Orbital Debris at the NASA Johnson Space Center. “The new NASA procedural requirements for orbital debris mitigation identifies the issue of the disposal of objects in lunar orbit and assigns responsibilities for ensuring that end-of-mission actions do not pose a threat to future lunar missions or to operations on the lunar surface.”
NASA’s intentions to keep the moon’s skies free of orbiting debris dates back to the lunar landings of the ’60s and 70’s.Â Â Â The big reason is that lunar orbits are unstable.
“The orbits of lunar satellites are normally chaotic and short-lived, due in part to lunar mascons,” Johnson told SPACE.com.
So, might there be other now defunct satellites still in lunar orbit at the mercy of the mascons that may pose a danger despite the new procedural requirements?
“Very few of the U.S. and Soviet vehicles left in lunar orbit during the 1960’s and 1970’s are assessed to still be in lunar orbit. Any objects remaining in lunar orbit would necessarily have to be at relatively high altitudes,” Johnson said.