Before revision: Effect of lunar mascons on satellite orbits Lunar mascons alter the local gravity above and around them sufficiently that low and uncorrected satellite orbits around the Moon are unstable on a timescale of months or years.
After revision: Effect of lunar mascons on lunar orbits of satellites Lunar mascons alter the local gravity above and around them sufficiently that low and uncorrected satellite orbits around the Moon are unstable on a timescale of months or years.