'Tunnelbot' will search for life on Jupiter's moon Europa by drilling to a hidden ocean

Nasa is working on a nuclear-powered robot to explore Jupiter's frozen moon Europa. It is believed the moon is home to a subterranean ocean which may harbour microbial life. Ice above the ocean is thought to be between 2 and 30 kilometres (1.2 and 18.6 miles) thick and researchers have proposed a tunnelling probe as the best way to penetrate the frosty shell and study its internal structure. Ice above the ocean is thought to be between 2 and 30 kilometres (1.2 and 18.6 miles) thick and researchers have proposed a tunnelling probe (pictured) may be the best way to penetrate the frosty shell Several flybys of the solar system's gas giant between 1995 and 2003 by NASA's Galileo spacecraft alerted scientists to the presence of the water. Researchers agree the best place to look is underneath the thick, planet-wide ice shell where water is in contact with a rocky core.