Jupiter. Radio image of Jupiter taken by the Very Large Array telescope. The colour code runs from dark blue for the darkest regions through green and yellow to red for the brightest parts. The emission from the planet itself appears at centre as a blue oval with a green-yellow stripe. Two bright areas are seen on each side of the planet. They are caused by electrons moving at high speed in Jupiter's magnetic field and emitting radiation in narrow beams by the synchrotron process. The red spot at bottom left appears brighter because the beam points towards the Earth. The image was made at a wavelength of 20cm.