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our solar system our solar system consists of a central star the Sun and

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and the eight planets that orbit the Sun.

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It is also made of asteroids, moons, comets, and lots more.

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The Sun was born in a vast cloud of gas and dust around 5 billion years ago.

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Our Sun is not unique in the universe, though.

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It is a common middle-sized yellow star, which scientists have named Sol,

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after the ancient Roman name.

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This is why our system of planets is called the solar system.

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There are trillions of other stars in the universe just like it,

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and many of these stars have their own systems of planets, moons, asteroids, and comets.

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The planet Mercury is the closest of the planets to the Sun.

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Because this planet lies so close to the Sun, and as a result somewhat near to Earth,

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It is visible to observers on Earth in the late evening or early morning sky.

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Because of this, Mercury has been a part of mythology and legend of almost every culture throughout the history of the Earth.

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Venus is in many ways Earth's sister planet.

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It is almost identical in size, chemistry, gravity, and density as the Earth.

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In other words, Venus is made up of almost the exact same types of materials as the Earth,

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and in about the same amounts.

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Venus has volcanoes, mountains, and sand, just like Earth.

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However, Venus is far too hot and has an atmosphere made up of almost entirely carbon dioxide,

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which means that no living thing could survive on the planet.

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Our planet is an oasis of life in an otherwise desolate universe.

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The Earth's temperature, weather, atmosphere, and many other factors are just right to keep us alive.

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There are currently over 7 billion people living on the Earth,

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and about 30% of the Earth's surface is covered with land, while about the other 70% is covered by oceans.

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Mars excites scientists because its mild temperament is more like the Earth's than any of the

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other planets.

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Evidence suggests that Mars once had rivers, streams, lakes, and even an ocean.

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As Mars' atmosphere slowly depleted into outer space, the surface water began to permanently

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evaporate.

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Today, the only water on Mars is either frozen in polar caps or underground.

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Jupiter is by far the largest planet in our solar system.

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The Earth could fit inside Jupiter more than 1,000 times.

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Jupiter is a very stormy planet.

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There are storms found throughout the atmosphere, and most of the storms seem to never end.

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The many different cloud formations and storms in the atmosphere also make Jupiter a very colorful planet.

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Saturn is most well known for its rings.

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However, it is not the only planet with rings.

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The rings are not solid, but rather are made up of particles of ice, dust, and rocks.

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The rings are held in place around Saturn by the moons that also orbit this large planet.

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The gravity of these moons also cause the gaps that are seen between the rings.

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Uranus has 27 moons.

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Five of these moons are large and the rest are smaller.

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The largest moon is called Titana.

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Like Jupiter and Saturn, Uranus is a gas giant, but Uranus is a little different.

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Unlike all the other planets, and most of the moons in our solar system, Uranus spins

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on its side.

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Not much was known about planet Neptune until it was visited by the spacecraft Voyager 2

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on August 25, 1989.

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Voyager 2 took many pictures of the planet,

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and much of what we know today about Neptune

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came from this single visit.

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These pictures show a brilliant blue planet

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with a few thin white clouds laced around its surface.