Temperature Map of Ganymede

NOTE: This JPEG image is made available in order to share with the public the excitement of new discoveries being made via the NASA/JPL Galileo spacecraft. Galileo scientists are in the process of calibrating and validating this data. The data necessary for scientific analysis will be released within one year of receipt of this orbit's last data.

This image is available only on the WWW; it is not available in hardcopy or other forms.

This map shows the temperatures for most of the surface of Ganymede made from data taken by the Photopolarimeter/Radiometer (PPR) instrument on June 26, 1996 as Galileo approached the sunlit side of the moon. The color bar shows the range of temperatures of this data, with the dark red being the coldest and white being the warmest. This is similar to the temperature forecast maps that you see on the evening news or in some newspapers. The difference between this map and one of Earth is that PPR measures the temperature of the surface (the ground), instead of air temperature. Ganymede is much colder than Earth, with these daytime temperatures ranging across the surface from 90 to 160 Kelvin (or -297 to -171 degrees Fahrenheit). Jupiter and its moons receive less than 1/30th the amount of sunlight that the Earth does, and Ganymede has essentially no atmosphere to trap heat. Ganymede's day is just over 7 Earth days long, the same time it takes to orbit Jupiter once.

To compare this temperature map to surface features of Ganymede, you can look at this Ganymede Image taken during the Ganymede 1 orbit. The PPR map covers almost the same area as the image but is rotated about 30 degrees to the west.

The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.

This and other data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://www.jpl.nasa.gov/galileo.

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