Infrared and visible images of Jupiter, 1979.
© National Aeronautics & Space Administration / Science & Society
The infrared image (left) is made up of earth-based measurements of Jupiter's emision at 5 microns wavelength. Infrared astronomy is useful in analysing Jupiter's meteorology; the bright areas are hot spots which represent sinking, anticyclonic regions of the planet's atmosphere. Comparison of the two images confirms that the bands of the atmosphere which appear darker at visible wavelengths are hotter than the lighter zones. The visible image of the planet was taken by Voyager 1. Two Voyager spacecraft were launched in 1977 to explore the planets in the outer solar system. Voyager 1 flew past Jupiter at 278,000 kilometres in March 1979 and then past Saturn at a height of 124,000 kilometres in November 1980.