Image-processed Voyager 1 photograph of Jupiter & three Jovian satellites; far right Europa (white), Io (red/brown) & nearly invisible at the bottom left is Callisto. The image was taken on the 5th February 1973 when the spacecraft was 28.4 million kilometres (17.5 million miles) away from the planet. Jupiter's Great Red Spot (oval), a large circulating atmospheric disturbance, is clearly visible in the southern hemisphere.