system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5: gravity anomalies on the moon.
gpt
The moon is not a perfectly symmetrical sphere of mass, it's lumpy inside, with some parts heavier/denser than others, likely due to higher concentrations of metals in those areas.  If you're above a dense part, gravity is a little stronger than elsewhere.  These are the so-called gravitational anomalies.