PICTURES from the Galileo spacecraft are fuelling speculation that
Jupiter鈥檚 moon Europa may have oceans, and possibly life. The images, released
by NASA last week, were beamed back by Galileo in February, during its closest
flyby of Europa so far.
The pictures show chunks of ice, much like icebergs on Earth, that appear to
have broken up and floated apart鈥攑erhaps on water or slushy ice
underneath. Liquid water could only exist if Europa has some kind of internal
heat source. This is most likely to be tidal heating caused by the constant
squeezing and stretching of the moon by Jupiter鈥檚 gravity.
That heat would probably also mean that the oceans contain volcanic
hydrothermal vents, where life could evolve in darkness. Some Galileo scientists
are saying that it is odds on that there is life on Europa.
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But others on the team are more cautious. 鈥淲hat we鈥檝e found is a fine habitat
for life鈥攁ll the right ingredients seem to be there,鈥� says Clark Chapman
of Southwest Research Institute in Boulder, Colorado, one of the Galileo imaging
team. 鈥淏ut no scientist can logically say that we know there鈥檚 life. That鈥檚 a
long step away from seeing ice rafts.鈥�