Surface Gravity of the Moon

One sixth of a g changes how bodies move, not how much they mass. Apollo astronauts found that walking was inefficient and adopted a loping bunny-hop, and the same acceleration is why a hammer and a falcon feather dropped by Dave Scott on Apollo 15 hit the dust together — Galileo's experiment finally run without air. Ascent from the lunar surface needs only about 1.9 km/s of delta-v, against roughly 9.4 km/s from Earth, which is the whole reason lunar-orbit rendezvous won the Apollo mission-mode argument.

Local gravity is not uniform. Dense mascons buried under the maria pull hard enough to perturb low lunar orbits noticeably, an effect that surprised the Lunar Orbiter program in 1966 and that GRAIL later mapped in detail; most low circular orbits around the Moon are unstable over months as a result.