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's wife Mirka gives birth to second set of twins. Roger Federer and his wife, Mirka, described themselves as incredibly happy after having their second set of twins. Boys Leo and Lenny are the latest addition to the Federer family, after the couple had twin girls, Myla Rose and Charlene Riva, four years ago.