Jakobshavn Glacier in west Greenland viewed by the Copernicus Sentinel-2 mission on 29 April 2019. In recent years, Greenland has been losing more ice through this glacier than from anywhere else on this huge ice sheet. Various types of satellite data have been used to understand and monitor the glacier’s flow over the last 20 years. This revealed that the glacier was flowing at its fastest and losing the most ice in 2012–13. In places, the main trunk of the glacier was deflating by 10 m a year as it adjusted dynamically to ice loss and melting. However, information from satellites such as ESA’s CryoSat and the Copernicus Sentinel-1 mission show that between 2013 and 2017, the region drained by the glacier stopped shrinking in height and started to thicken. The overall effect is that Jakobshavn is now flowing more slowly, thickening, and advancing toward the ocean instead of retreating farther inland.