Julia Hinde reports from the annual American Association for the Advancement of Science meeting in Seattle
Scientists looking for extra-terrestrial life are turning their attentions to Jupiter's moon Europa.
Eugene Shoemaker of the United States Geological Survey told the meeting that he would lay bets on Europa as being the most likely place to find signs of life beyond Earth, though he still supported work to find life on Mars. His views were echoed by John Delaney of the University of Washington.
Their hopes for Europa rest on geological evidence which suggests the moon harbours a massive ocean and possibly vulcanism below its icy crust to prevent the water from freezing. Work on earth has shown that volcanoes can support life independent of the sun, as long as liquid water is present.
Interest in Europa has been boosted by pictures from the US spacecraft Galileo, which has produced spectacular images of its icy surfaces.