The world's largest canyon may be sitting beneath the Antarctic ice sheet and if satellite readings are accurate, it stretches more than twice as long as the Grand Canyon.

According to Discovery News, parts of the canyon in east Antarctica sit beneath ice a mile thick. An estimated 621 feet long, the canyon is more than twice as long as the Grand Canyon and it can be as deep as 3,280 feet.

"Our analysis provides the first evidence that a huge canyon and a possible lake are present beneath the ice in Princess Elizabeth Land. It's astonishing to think that such large features could have avoided detection for so long," study lead researcher Stewart Jamieson, of Durham University, said in a press release. "This is a region of the Earth that is bigger than the UK and yet we still know little about what lies beneath the ice. In fact, the bed of Antarctica is less well known than the surface of Mars. If we can gain better knowledge of the buried landscape we will be better equipped to understand how the ice sheet responds to changes in climate."

The researchers published their findings in the journal Geology.

"Antarctic scientists have long recognized that because the way ice flows, the landscape beneath the ice sheet was subtly reflected in the topography of the ice sheet surface. Despite this, these vast deep canyons and potential large lake had been overlooked entirely," study co-author Neil Ross, of Newcastle University, said in the release. "Our identification of this landscape has only been possible through the recent acquisition, compilation and open availability of satellite data by many different organizations (e.g. NASA, ESA and the US National Snow and Ice Data Center), to whom we are very grateful, and because of some serendipitous reconnaissance radio-echo sounding data acquired over the canyons by the ICECAP project during past Antarctic field seasons."