Io - Galileo

Io in front of Jupiter

Galileo image of Io with Jupiter in the background. Io was about 487,000 km away when this image was taken, and Jupiter 908,000 km. The hemisphere of Io shown always faces away from Jupiter. Like the Earth's Moon, Io is tidally locked to Jupiter. The color has been enhanced to bring out details on Io's surface. This also accounts for Jupiter's blue color. Io is the most active volcanic body in the solar system, and the black and red areas are recent volcanic deposits, probably no more than a few years old. The black and gray circular area just right of the center of the disk is the active volcano Prometheus. The surface appears to have undergone substantial change since the Voyager images were taken in 1979, and even exhibits changes over the period of months between encounters. Io is 3640 km in diameter and north is up. (Galileo, P-47971)
Larger image (266K) jpg

High resolution tif file (1.8M)

Location & Time Information
Date/Time (UT): 1996-06-25
Distance/Range (km): 487,000.
Central Latitude/Longitude (deg): N/A
Orbit(s): Flyby

Imaging Information
Area or Feature Type: global view
Instrument: Solid State Imaging CCD Camera
Instrument Resolution (pixels): 800 x 800, 8 bit
Instrument Field of View (deg): 0.46 x 0.46
Filter: N/A
Illumination Incidence Angle (deg): N/A
Phase Angle (deg): N/A
Instrument Look Direction: N/A
Surface Emission Angle (deg): N/A

Ordering Information
CD-ROM Volume: N/A
NASA Image ID number: P-47971
Other Image ID number: MRPS-77053
NSSDC Data Set ID (Photo): NSD XD-12A
NSSDC Data Set ID (CD): N/A
Other ID: N/A


[NASA Logo] Authors/Curators:

Dave Williams,, (301) 286-1258
Code 690.1, NASA Goddard Space Flight Center
Greenbelt, MD 20771, USA

Jay Friedlander,, (301) 286-7172
Code 612.4, NASA Goddard Space Flight Center
Greenbelt, MD 20771, USA

NASA Official: Ed Grayzeck,

Last updated: 24 September 2015