There is some evidence, in the form of ice cores drilled to about 400 m (1,300 ft) above the water line, that Lake Vostok's waters may contain microbial life. The frozen surface of the lake shares similarities with Jupiter's moon, <answer>Europa</answer>. If life is discovered in Lake Vostok, it would strengthen the argument for the possibility of life on <answer>Europa</answer>. On 7 February 2008, a NASA team embarked on a mission to Lake Untersee, searching for extremophiles in its highly alkaline waters. If found, these resilient creatures could further bolster the argument for extraterrestrial life in extremely cold, methane-rich environments.
To what does the frozen surface of Lake Vostok resemble?
Europa