PLANETS IN OUR SOLAR SYSTEM
Nine known planets revolve around the sun in our solar system. The planets, shown here in order by their distance from the sun, vary greatly in size, rotation, color, and composition. For instance, Mercury, a small, hot planet, is a mean distance of 58 million km (36 million mi) from the sun, while icy Pluto is 5.9 billion km (3.67 billion mi) away. Venus rotates relatively slowly around its axis, so that one day on the planet equals 58 earth days. Jupiter is the largest planet in the system, with a volume 1400 times greater than that of earth. Saturn has a broad set of rings and features more than twenty satellites, the most of any planet. Mars is characterized by orange coloration and distinct polar ice caps, while methane in the atmospheres of Uranus and Neptune makes these planets a bright blue-green. In addition to being the farthest planet from the sun, Pluto has the longest period of revolution: 247.7 years.