But when the question of how to explore the lake came up, not long after its discovery, the Vostok scientists faced a serious dilemma. The lake is under immense pressure, and to breach the ice would have devastating consequences.
Roger Federer: Swiss star will play on until at least 2019. Updated 1815 GMT (0215 HKT) February 21, 2017. Chat with us in Facebook Messenger. Find out what's happening in the world as it unfolds.
Roger Federer has struggled with injuries this yearGetty. Tennis legend Roger Federer has admitted that pulling out of the recently concluded 2016 French Open was a good move as he readies himself for competing at the Mercedes Open in Stuttgart which starts on 6 June.