Lake Vostok micro-organism. Scanning electron micrograph (SEM) of an as yet unidentified micro- organism discovered in ice from Lake Vostok, Antarctica. This freshwater lake is trapped beneath up to 4 kilometres of ice, and may harbour a unique ecosystem. The lake's water stays liquid due to geothermal heat, and has been isolated from the rest of the world for millennia. The ice cores containing the specimens were up to 400,000 years old. This organism, nicknamed sphere", may be new to science. Lakes of water under ice are also thought to exist on Jupiter's moon Europa. Magnification: x3500 when printed 10cm wide."