During its long mission, Galileo has found evidence of liquid water on Jupiter's moons Europa and Callisto. Oceans under the icy surfaces could provide habitats were microscopic life might already exist.
But these moons are not the only objects orbiting Jupiter that might contain life. Galileo may be carrying with it single-celled organisms from home. Some Earth microbes are known to have survived for years in space in a dormant state.
Terrestrial microorganisms could conceivably pose a threat to microbes that may exist on Europa or Callisto. The extinction of life there would be an incalculable loss. Hence, NASA plans to aim the aging towards Jupiter, where the tremendous pressure of the planet's gas clouds will crush the spacecraft and any organisms on it completely.
But the work of Galileo isn't over quite yet. The crash won't take place until December 2002 at the earliest.
Aug 16, 2004 | MISSIONS
Scientists Discover Ganymede has a Lumpy Interior
(NASA - JPL) - Scientists have discovered irregular lumps beneath the icy surface of Jupiter's largest moon.
Sep 22, 2003 | MISSIONS
Galileo End of Mission Status
(NASA) - Galileo plunges into Jupiter to end its 14-year mission.
Sep 19, 2003 | MISSIONS
Surprising Jupiter
(NASA - JPL) - NASA's Jet Propulsion Laboratories discusses the accomplishments of the Galileo spacecraft.
Sep 15, 2003 | MISSIONS
Historic Galileo Mission Nears End
(NASA) - On September 21, Galileo will end its mission with a plunge into Jupiter's atmosphere.
Apr 10, 2003 | MISSIONS
Galileo Millennium Mission Status
(NASA - JPL) - Galileo discovers new space rocks near inner moon of Jupiter.
Feb 26, 2003 | MISSIONS
Galileo's Jupiter Tour Winding Down
(JPL) - The flight team for NASA's Jupiter-orbiting Galileo spacecraft will cease operations on February 28 after a final playback of scientific data from the robotic explorer's tape recorder.
Oct 11, 2002 | SCIENCE, MISSIONS
Boost for Life on Jupiter Moon
(BBC) - New observations made by the Galileo spacecraft may strengthen the argument for life on Europa.
Dec 04, 2001 | SCIENCE, MISSIONS
Ocean Inside Jupiter's Moon Callisto May Have Cushioned Big Impact
(NASA) - A recent image from NASA's Galileo spacecraft adds evidence that Callisto may hold an underground ocean.
Aug 23, 2001 | SCIENCE, MISSIONS
Callisto's Bizarre Landscape Revealed
(NASA) - New images from NASA's Galileo spacecraft give the highest resolution view ever seen of any of Jupiter's moons.
Jul 27, 2001 | SCIENCE, MISSIONS
Eilene Theilig: Faith, by Jupiter
(CNN) - The manager of NASAÂs Galileo mission to Jupiter discusses the 12-year-old spacecraft and what it has taught us so far.
May 25, 2001 | MISSIONS
Galileo Succeeds in Its Closest Flyby
(NASA) - NASA's Galileo spacecraft has successfully completed a flyby of Jupiter's moon Callisto, closer than any of the spacecraft's previous flybys of Jovian moons.
May 22, 2001 | MISSIONS
Galileo's Last Encounter with Jupiter's Callisto
(NASA/JPL) - On its third and final tour of duty in the Jovian system, NASA's dauntless Galileo spacecraft makes its closest pass yet to Jupiter's outermost large moon. On Friday the orbiter should skim over Callisto, at an altitude of about 123 kilometers, or 76 miles.
Apr 13, 2001 | SCIENCE, MISSIONS
Focus on Europa
(NASA Astrobiology Institute) - Scientists from a variety of disciplines met recently to consider the possibility of life on Europa, and to plan how to look for it.
Mar 16, 2001 | SCIENCE, MISSIONS
Through Thick or Thin: Exploring Europa's Outer Layer of Ice
(NASA Astrobiology Institute) - When NASA's Galileo spacecraft sent back images and data of the Jovian moon Europa, scientists began thinking seriously that life just might exist on this enigmatic, frozen world.
Mar 09, 2001 | SCIENCE, MISSIONS
Ganymede's liquid past
(NASA) - Long swaths of bright, flat terrain on the surface of Jupiter's icy moon Ganymede may testify that water or slush emerged there about a billion years ago, say planetary scientists.
Feb 02, 2001 | SCIENCE, MISSIONS
Jovian moons
(NASA Astrobiology Institute) - Jupiter's four largest moons were discovered by Galileo in 1610. Three of them might hold oceans of liquid water beneath their icy exteriors. Liquid water is a prerequisite for life.
Dec 28, 2000 | MISSIONS
Galileo swings by Ganymede
(Science@NASA) - The space probe photographed and collected data on Jupiter's largest moon.
Dec 17, 2000 | SCIENCE, MISSIONS
Evidence of ocean on Jupiter's moon Ganymede
(NASA) - Data from the Galileo space probe suggest that liquid water may lie beneath Ganymede's icy crust.
Dec 08, 2000 | MISSIONS
NASA's Galileo celebrates five years orbiting Jupiter
(NASA) - In its years of service, Galileo has provided evidence of liquid water on Europa and Callisto.
Aug 25, 2000 | SCIENCE, MISSIONS, TECHNOLOGIES
Strong evidence of ocean of water on Europa
(NASA) - Magnetic readings from the Galileo space probe provide the latest indication of liquid water under the thick ice of this moon of Jupiter.
Aug 22, 2000 | SCIENCE, MISSIONS, TECHNOLOGIES
Galileo returning data on Ganymede and Europa
(Spaceflight Now/NASA) - Measurements of Ganymede's magnetic field may indicate whether there is an ocean of water beneath its surface.
Aug 10, 2000 | SCIENCE, MISSIONS
Scientists uncover evidence of tidal squeezing on Europa
(space.com) - Images show folds where Europa's icy crust has been compressed by tidal forces from Jupiter.
Jun 08, 2000 | SCIENCE, MISSIONS, TECHNOLOGIES
Cracks in Europa's ice may create habitat for life
(space.com) - As icebergs slide past each other, friction may melt ice. The liquid water might provide a habitat for living organisms.
Apr 20, 2000 | SCIENCE, MISSIONS
New image of Europa
(Spaceflight Now) - The image suggests the presence materials conducive to life on Europa's icy surface.
Feb 21, 2000 | MISSIONS
With mission ending, NASA considers crash-landing Galileo probe
(Yahoo!/AP) - The spacecraft could send valuable data as it plunges into Jupiter or one of its moons. NASA will not crash Galileo into Europa for fear of planetary contamination.
Aug 12, 1999 | MISSIONS
Galileo to fly by Europa today
(NASA) - The moon of Jupiter is a prime target in the search for life elsewhere in the solar system.
Oct 23, 1998 | SCIENCE, MISSIONS, TECHNOLOGIES
Signs of water on Callisto
(Science@NASA) - Scientists may have discovered a salty ocean and some ingredients for life on Jupiter's moon.
Jul 15, 1998 | SCIENCE, MISSIONS
Evidence of ancient ocean on Ganymede
(ABC News) - Images taken by the Galileo spacecraft indicate that Jupiter's largest moon may once have had an ocean of liquid water.
