"UT's Experimental Mission Reveals Secrets of Gravity Holes and Ice Cap Melt"
Researchers have used the Gravity Recovery and Climate Experiment (GRACE) satellite mission to study changes in mass on Earth, including the discovery of "gravity holes" - spots on the planet's surface with less gravity than others. GRACE, launched in 2002, mapped the planet's mass by measuring the distance between two satellites as they orbited the Earth. The mission not only revealed changes in gravity but also provided evidence of melting ice caps. The data collected by GRACE was so significant that NASA launched a follow-up mission, GRACE-FO, in 2018.