This is a montage of planetary images taken by spacecraft managed by the Jet Propulsion Laboratory in Pasadena, CA. Included are (from top to bottom) images of Mercury, Venus, Earth (and Moon), Mars, Jupiter, Saturn, Uranus and Neptune. The spacecraft responsible for these images are as follows:the Mercury image was taken by Mariner 10,the Venus image by Magellan,the Earth image by Galileo,the Mars image by Viking, andthe Jupiter, Saturn, Uranus and Neptune images by Voyager.
Pluto is not shown as no spacecraft has yet visited it. The montage was created soon after Voyager 2's historic encounter with Neptune in August 1989 and thus takes the perspective of looking back from Neptune (in the foreground) toward the Earth. The inner planets (Mercury, Venus, Earth, Moon, and Mars) are roughly to scale to each other; the outer planets (Jupiter, Saturn, Uranus, and Neptune) are roughly to scale to each other, with the exception of Neptune, which as a foreground object, is shown larger. PIA01341 is the same montage with Neptune shown more to scale. Actual diameters are given below:
Sun 1,390,000 km Mercury 4,879 km Venus 12,104 km Earth 12,756 km Moon 3,475 km Mars 6,794 km Jupiter 142.984 km Saturn 120,536 km Uranus 51,118 km Neptune 49,528 km Pluto 2,390 km
For more information on the Planets, a good place to start is the Planets section of the NASA Solar System Exploration Home Page at http://sse/features/planets/planetsfeat.html.