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.
She is the wife of professional tennis player Roger Federer, having first met him at the 2000 Summer Olympics. She retired from the game in 2002 due to a persistent foot injury. She has since frequently been seen on the ATP circuit attending her husband's matches.