Exploration
Several probes flying by or orbiting Jupiter have explored Ganymede more closely, including four flybys in the 1970s, and multiple passes in the 1990s to 2000s.
Pioneer 10 approached in 1973 and Pioneer 11 in 1974, and they returned information about the satellite. This included more specific determination on physical characteristics and resolving features to 400 km (250 mi) on its surface. Pioneer 10's closest approach was 446,250 km.
Voyager 1 and Voyager 2 were next, passing by Ganymede in 1979. They refined its size, revealing it was larger than Saturn's moon Titan, which was previously thought to have been bigger. The grooved terrain was also seen.
In 1995, the Galileo spacecraft entered orbit around Jupiter and between 1996 and 2000 made six close flybys to explore Ganymede. These flybys are G1, G2, G7, G8, G28 and G29. During the closest flyby—G2—Galileo passed just 264 km from the surface of Ganymede. During a G1 flyby in 1996, the Ganymedian magnetic field was discovered, while the discovery of the ocean was announced in 2001. Galileo transmitted a large number of spectral images and discovered several non-ice compounds on the surface of Ganymede. The most recent spacecraft to explore Ganymede up close was New Horizons, which passed by in 2007 on its way to Pluto. New Horizons made topography and composition maps of Ganymede as it sped by.
Read more about this topic: Ganymede (moon)
Famous quotes containing the word exploration:
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