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.
In the Wimbledon finals this weekend, two of the older players on tour have a shot at winning titles. Serena Williams, who is 33 years old, will play 21-year-old Garbine Muguruza on Saturday in the womenâs final. And on Sunday, Roger Federer, who is also 33, will play 28-year-old Novak Djokovic. In the Open era, 33 has historically been pretty old to be near the top of the rankings.