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Reader Supplement HERE & NOW Galileo Spacecraft MissionVicki M. Harder |
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Reader Supplement HERE & NOW Galileo Spacecraft MissionVicki M. Harder |
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The Galileo spacecraft's mission is to conduct detailed studies of the planet Jupiter, its largest moons and the Jovian magnetic environment. Galileo was launched in October 1989 and entered orbit around Jupiter on December 7, 1995. The spacecraft will make repeated flybys of Jupiter and its moons during it's two-year mission.
The spacecraft was named for the Italian Renaissance scientist Galileo, who discovered Jupiter's major moons in 1610 with the first astronomical telescope. The 2,223-kilogrom (2/1/2-ton) Galielo orbiter spacecraft carries 10 scientific instruments; there are another sidx on the 339-kilogram (746-pound) probe. The spacecraft radio link to Earth and the probe-to-orbiter radio link serve as instruments for additional scientific investigations. Of Jupiter's 16 satellites - Ganymede, Europa, and Io, have been visited by Galileo whose results are reported on in the Science News Reader articles. |
En route to its first rendezvous with the Jovian moon Ganymede, the Galileo spacecraft took images from Io. In the Science News Reader article Galileo spacecraft glimpses changes on Io, scientists noticed many changes on the moon's surface when compared to images sent back by Voyager some 17 years earlier. These changes are all related to Io's volcanic activity.
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As reported in Picturing a new world: Views of Ganymede the Galileo spacecraft flew within 830 km of the Jovian moon capturing details of the planet never before imaged in sharp detail. There has been a dramatic improvement in the quality of the images from the 1979 flyby of the Voayger 2 spacecraft to the June 27, 1996 flyby of Galileo.
These new images have changed the ideas formed from the Voyager flyby. What was thought to be the youngest areas of the moon are now seen to be quite old, fractures suggest that Ganymeded may once have possessed a subsurface ocean, and a weak magnetic field has been detected. |
During the Sept. 6, 1996 flyby of the Jovian moon Galileo revealed that Ganymede may be experienceing the sublimation and redeposition of water-ice in its northern regions. Images from the June 27 flyby were combined with those of Septermber 6 to create a stereo perspective of the planet, giving scientists a 3-dimensional view of the surface.
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| On June 27 the Galileo spacecraft passed close enough to Europa to photograph its surface, just hours after a flyby of Ganymede. According the the Science News Reader article Visions of Eurpoa: Galileo tour heightens speculation about life on Jovian moon, the Galieleo spacecraft is scheduled to take extreme close-ups of Europa during 3 flybys. During the December 19 flyby the craft imaged equatorial features as small as 20 meters across; on February 20, 1997 Galileo examined details of Europa's midlatitudes, and in December 1997 the spacecraft will zoom in on the Jovian moon's north pole region. |
In all flybys scientists will closely scrutinize evidence of an ocean on the Jovian moon. Unfortunately, the Galileo spacecraft lacks instruments to directly detect subsurface water and so the evidence must be collected indirectly. Several models have been proposed to account for an ocean on Europa. |
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