Credit: NASA

A joint mission between NASA and the German Research Centre for Geosciences (GFZ), the GRACE mission – Gravity Recovery and Climate Experiment – launched in 2002 and collected data on fluctuations in Earth’s gravity until October 2017, detailing changes to ice sheets and groundwater, and helping revolutionise the science of the so-called cryosphere. This NASA video explains its techniques and impact, which will be continued through its successor mission, GRACE-FO.