In Antarctica, Russian scientists posed at the site where they say they've drilled through to Lake Vostok. The sign indicates that the breakthrough happened on Feb. 5, 2012. Russia's Federal Service for Hydrometeorology and Environmental Monitoring hide caption

itoggle caption Russia's Federal Service for Hydrometeorology and Environmental Monitoring

While a team of Russian scientists were drilling ice core samples from their Vostok base in Antarctica, new satellite imagery revealed the outline of a lake the size of New Jersey buried two miles underneath the ice. It's thought to be the third largest lake on the planet. Earth Observatory/NASA hide caption

itoggle caption Earth Observatory/NASA