Introduction:
              This is a scale model of the solar system made in our science class. Our scale in planet diameter is one to five billion. Our scale in distance from the sun is one to ten trillion. We made the Sun using a balloon and tissue paper. Most of the planets are made of a mixture of clay and salt dough. Now we will tell you about our solar system.

The Sun:
               The Sun’s gravity holds all the planets in orbit, 99.8 percent of the mass of the solar system is the sun. It has an interior and an atmosphere; it does not have a solid interior. It is like a giant furnace. The sun’s energy comes from nuclear fusion. The sun’s core or center reaches about 15 million degrees Celsius.

 Mercury:
         The first planet in the solar system is Mercury. Mercury is not much bigger than Earth’s moon. Mercury is made mostly of iron and metals. Since Mercury is so close to the Sun, astronomers are unable to get a good view of it. Mercury has an extremely thin atmosphere. During the day Mercury reaches up to 450*C and at night it reaches ---170*C. Mercury has the greatest range of temperatures in the solar system. The only knowledge about Mercury scientists have is from Mariner 10, a probe which was sent to study Mercury.

Venus:
         Venus is the second planet from the Sun. Venus is a lot like Earth in size that it is sometimes called Earth’s twin. Astronomers also think that the density of Venus is also similar to that of Earth’s. Venus rotates extremely slowly, while it takes about 8 months for it to revolve around the Sun. Venus rotates so slowly, that it’s day is longer than it’s year. The prediction proposed by astronomers is that Venus was hit by a large object billions of years ago, causing the direction of Venus’ rotation to change. The atmosphere of Venus is so thick that every day is a cloudy one. If you could stand on the surface of Venus, you would immediately be smashed by the weight of it’s pressure.

Earth:
            Earth is the third planet from the Sun. The Earth’s atmosphere extends 100 kilometers above it’s surface. Oxygen makes up about 20 percent of Earth’s atmosphere. Almost all the rest is made of nitrogen gas, with a little carbon dioxide. Most of Earth, 70 percent, is covered with water. No other planet in our solar system has oceans like Earth’s.

Mars:
          Mars is the fourth planet in the solar system. Mars is called the red planet because of its reddish look. The atmosphere on Mars is mostly made of carbon dioxide. Today some water remains on Mars. The water is frozen in the polar caps. Mars’s polar caps in the winter are frozen over because of carbon dioxide. Like Earth, Mars is also tilted on its axis causing seasons. About one hundred years ago people thought plants were growing on Mars, later astronomers proved this to be false.

Asteroid Belt:
           In between Mars and Jupiter is the Asteroid Belt. Astronomers have found more than 10,000 asteroids. Ceres, Pallas, Juno, and Vesta are among the twelve asteroids that are over 250 kilometers across.

Jupiter:
            The 5th planet from the sun is Jupiter. Jupiter is the largest planet in the solar system. If Jupiter were any bigger it would become a Sun. Jupiter’s atmosphere is made mostly of helium and hydrogen. Jupiter has 17 known moons. Galileo discovered four of Jupiter’s moons, which are Io, Europa, Ganymede, and Callisto. Jupiter is probably most famous from its Great Red Spot. The Great Red Spot is a violet storm on Jupiter. Many violent storms occur on Jupiter.

Saturn:
        Saturn is the 6th planet from the Sun. Saturn is the second largest planet in the solar system. Saturn has a thick atmosphere made up of mostly hydrogen and helium. Saturn is the only planet in the solar system that is less dense than water. Saturn is surrounded by beautiful rings made of chunks of rocks and ice.

Uranus:
         Uranus is 2,871,000,000km from the sun. Uranus is the 7th planet from the sun. Uranus is about four time’s the diameter of the earth. But it’s smaller than Jupiter and Saturn. Uranus is twice as far from the Sun as Saturn. And it’s very cold.
    Uranus was found in 1781. They said it was the first new planet discovered since ancient time’s.
    I found out it has 17 moon’s. Uranus’s diameter, in kilometer’s, are 51,200. The period of rotation in Earth day’s are 0.72.

Neptune:
         Neptune is 4,497,000,000km. From the Sun. Neptune is 30 time’s farther than Earth’s distance from the Sun.  Neptune’s atmosphere contains visible clouds on the surface. Astronomers discovered eight moon’s revolving around Neptune. Neptune’s largest moon is “Triton.” Neptune is the 8th planet from the Sun. The diameter is 49,500 kilometer’s. In Earth day’s the period of rotation is 0.67. The average distance is 4,497,00,000. The period of revolution in Earth’s years are 165 days.

Pluto:
        Pluto is the 9th and last planet from the sun. Pluto has one moon. It is called Charon. Pluto and Charon have solid surfaces and masses much less than the Earth. Pluto is so small that astronomers think it should not be considered a planet.