So How's the Europan Seafood?
Even if life does exist on Europa, it is still too early to take up extraterrestrial ice fishing. Most likely, only very primitive forms of life would exist (microbes or bacteria), but discovery of living organisms in any form would cause a universal change in human understanding in the evolution and creation of life. The importance of such a discovery is why NASA is now concentrating its efforts into probing potential spots for life in the solar system.
Besides the current Galileo mission to Jupiter, NASA launched the Cassini spacecraft on Oct. 15, 1997. Cassini will rendezvous with Saturn in June 2004, and primarily study Titan, the largest moon of Saturn. Titan has a thick (1.6 times as thick as Earth's) nitrogen atmosphere, and is larger than both Pluto and Mercury. The Cassini spacecraft will send a probe into Titan's atmosphere, gaining new insight into the atmospheric and surface conditions. Titan may prove to be the most likely place for life to exist besides Earth. It is believed that the chemistry on Titan contains the molecules, hydrocarbons, needed for life to begin.
Galileo's Ongoing Mission
As scientists wait for Cassini to arrive at Saturn, they are busy directing Galileo and analyzing data already transmitted. While it is doubtful Galileo will find any direct evidence for a subsurface ocean on Europa, scientists are using stereo imaging to photograph sections of the moon's surface, and information on Europa's magnetic and gravitational fields to help unlock clues on its internal environment.
After Galileo finishes with its passes around Europa, it will proceed to fiery Io to study the volcanic activity, from perilously close range, until the termination of its mission on New Year's Eve 2000.
NASA is currently planning and designing future missions to Europa concerned with more direct evidence of a subsurface ocean. Both Europa Ice Clipper and Europa Ocean Explorer are proposed missions in the design stages concerned with robotic exploration of the surface and drilling to the possible ocean below. These missions could proceed after the Europa Orbiter Mission (beginning 2003) maps the surface of the moon at high resolution. For now, Galileo will continue to provide the groundwork for future exploration of a possible location of extraterrestrial life.