Hiawatha glacier and crater in Greenland, satellite image with ice cover partially removed. The rounded structure at centre is a large impact crater that is covered in ice (removed in this view) from the Hiawatha Glacier in north-western Greenland. This is the first meteorite impact crater found under the Greenland ice sheet. It is one of the largest impact craters on Earth, measuring around 300 metres deep and more than 30 kilometres in diameter. It has been studied using satellites and airborne ice-penetrating radar. The crater was formed less than 3 million years ago, probably towards the end of the last ice age. This image combines data from various satellites and was obtained on 14 November 2018. For this area with the ice cover present, see image C047/9571.