After more than two decades of drilling in Antarctica, Russian scientists have reached the surface of a gigantic freshwater lake hidden under miles of ice for some 20 million years, a lake that may hold life from the distant past and clues to search for life on other planets. Reaching Lake Vostok is a major discovery avidly anticipated by scientists around the world hoping that it may allow a glimpse into microbial life forms, not visible to the naked eye, that existed before the Ice Age.