The Western portion of Antarctica has melted so much over the past few years that Earth’s gravity is weaker than it used to be. I’m just going to leave that here and let it sink in for a second.
The European Space Agency (ESA) has special satellites that it uses to measure variations in Earth’s gravitational field. Basically, the mission involves sending up two satellites that remain in orbit near one another. Because of their proximity, slight changes between their positions signify changes in gravity, which computer programs then interpret. From 2009-2013, the ESA conducted the “Gravity field and steady-state Ocean Circulation Explorer” (GOCE) mission, which gave scientists thorough and accurate gravitational measurements on an unprecedented level. The program was able to map the predictable variations due to the planet’s rotation and other geological shifts, but the most recently measured shift is much more substantial than that.