As shown in the solar system poster to the left, the nine planets revolve around the sun. The distance from the earth to the sun, known as an astronomical unit is 150 million kilometers (93 million miles). Pluto, the most distant planet is 39.4 astronomical units from the sun.
Of all planets in the solar system, ours is the only known to support life. Some scientists do believe that there is a high chance of life existing on the planet Mars though this has yet to be proven beyond doubt.
Looking at the solar system poster to the right, you can see that the sun is depicted as a red hot ball. In reality, the sun is a 'medium-sized' star in terms of its size and luminosity. What really goes on in the sun is a chemical reaction called nuclear fusion by which hydrogen gas is converted to helium. Scientists estimate that the sun will continue to shine at its present rate for another 6 billion years before it eventually dies out. For now, it provides sufficient light and energy to sustain life on earth as well as maintaining a balance in the solar system.
The solar system poster to the left shows the relative sizes of the planets. The inner planets (Mercury, Venus, Earth and Mars) are relatively small in size and composed of rock and iron. The outer planets (Jupiter, Saturn, Uranus and Neptune) are large and consist chiefly of hydrogen, helium and ice. Pluto is an outer planet that is very small in size. Between Mars and Jupiter is an asteroid belt consisting of interplanetary dust, ash and asteroids that revolve around the sun.
A number of planets such as Earth, Saturn, Jupiter and Uranus have moons that go around them. Saturn is rather famous for the beautiful rings that encircle it - these rings are shown on all solar system posters on this page including the solar system poster to the right. The rings of Saturn actually consist of dust, gas and tiny icy particles. Comets crisscross their way through the solar system. Unlike the planets, they do not revolve around the sun on definite elliptical paths. The most famous comet in recent history is Halley's comet which returns to the inner solar system every 75 years and was last seen in 1986. Parts of comet Shoemaker-Levy 9 collided with Jupiter in 1994 creating such a large explosion which could be seen here on earth with the aid of a telescope.
We hope you find these solar system posters educating and useful to your needs. We are grateful to Art.com for permitting us to make use of them on our site. Clicking on each solar system poster links you to the Art.com site.
More information on other posters is also available.
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