What is the Solar System?
The Solar System is our neighbourhood in space. You PROBABLY live somewhere on the world. Well, this world's real name is "Earth," and it's part of a whole family of objects that orbit the Sun.
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The Solar System formed 4.57 billion years ago, which would be 4 570 000 000 years ago, but it's full process dates back over 5 billion years! A nearby star died and exploded into a supernova, and all those shock waves sent a cloud of gas and dust (a solar nebula) spinning. The centre started condensing and heating up until the Sun was formed. Outside, dust and gas also started clumping together, pulled by the Sun's gravity but moving too fast to actually collide with the Sun. These formed everything that orbits the Sun today!
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Solar System Objects
STAR: Huge balls of plasma and a bit of gas. When stars are in their most stable part of their life, they fuse (combine) four hydrogen atoms into one helium atom. The energy from this is radiation, such as heat and light. The Sun is a star
PLANET: A round object that orbits its star, namely the Sun. A planet should also have "cleared their neighbourhood," according to the International Astronomical Union (IAU).
TERRESTRIAL PLANET: A planet that is made of rock and metal. They have a solid surface to walk on, assuming you don't die in some of their conditions. The word "terrestrial" came from "terra," Latin for land or earth. Mercury, Venus, Earth and Mars are the terrestrial planets.
JOVIAN PLANET: A planet that is made of gas and liquid. They are often inaccurately called the GAS GIANTS, but they have more liquid than gas. The word "Jovian" comes from the god "Jove." Jove, being a god, is very big compared to humans, just like the Jovian planets are big compared to the other planets. Both Jove and the Jovian planets are stormy and powerful, so this name is more fitting. Jupiter, Saturn, Uranus and Neptune are the Jovian planets.
DWARF PLANET: Dwarf planets supposedly haven't cleared their neighbourhood, though the IAU never specified how large a neighbourhood has to be. In addition, the planets Earth, Mars, Jupiter and Neptune haven't cleared their orbits, never mind their "neighbourhoods," but are still considered planets. Because of these conflicts, this site will consider dwarf planets as full-fledged planets, but in a third category. Ceres, Pluto, Haumea, Makemake and Eris are dwarf planets.
DWARF PLANET CANDIDATE: Possible dwarf planets. There are five dwarf planet candidates that are larger than Ceres, even one that is smaller than only Pluto and Eris, but haven't been recognised by the IAU. These five candidates are Orcus, 2002 MS4, Quaoar, 2007 OR10 and Sedna.
ASTEROID: Lumps of rock, metal and sometimes ice that are just too small to pull themselves into a round shape.
COMET: Lumps of water ice, dry ice and sand that are just too small to pull themselves into a round shape. When they get nearer to the Sun, some of the ices vapourise and form a lovely tail.
METEOROID: Lumps chipped off asteroids and comets.
MOON: Not to be confused with the Moon. Most planets have moons, which are objects (not man-made) that revolve around another object (not including a star). A moon's orbit is also not affected by the gravity of others. There are around 550 moons in the solar system.
PLANET: A round object that orbits its star, namely the Sun. A planet should also have "cleared their neighbourhood," according to the International Astronomical Union (IAU).
TERRESTRIAL PLANET: A planet that is made of rock and metal. They have a solid surface to walk on, assuming you don't die in some of their conditions. The word "terrestrial" came from "terra," Latin for land or earth. Mercury, Venus, Earth and Mars are the terrestrial planets.
JOVIAN PLANET: A planet that is made of gas and liquid. They are often inaccurately called the GAS GIANTS, but they have more liquid than gas. The word "Jovian" comes from the god "Jove." Jove, being a god, is very big compared to humans, just like the Jovian planets are big compared to the other planets. Both Jove and the Jovian planets are stormy and powerful, so this name is more fitting. Jupiter, Saturn, Uranus and Neptune are the Jovian planets.
DWARF PLANET: Dwarf planets supposedly haven't cleared their neighbourhood, though the IAU never specified how large a neighbourhood has to be. In addition, the planets Earth, Mars, Jupiter and Neptune haven't cleared their orbits, never mind their "neighbourhoods," but are still considered planets. Because of these conflicts, this site will consider dwarf planets as full-fledged planets, but in a third category. Ceres, Pluto, Haumea, Makemake and Eris are dwarf planets.
DWARF PLANET CANDIDATE: Possible dwarf planets. There are five dwarf planet candidates that are larger than Ceres, even one that is smaller than only Pluto and Eris, but haven't been recognised by the IAU. These five candidates are Orcus, 2002 MS4, Quaoar, 2007 OR10 and Sedna.
ASTEROID: Lumps of rock, metal and sometimes ice that are just too small to pull themselves into a round shape.
COMET: Lumps of water ice, dry ice and sand that are just too small to pull themselves into a round shape. When they get nearer to the Sun, some of the ices vapourise and form a lovely tail.
METEOROID: Lumps chipped off asteroids and comets.
MOON: Not to be confused with the Moon. Most planets have moons, which are objects (not man-made) that revolve around another object (not including a star). A moon's orbit is also not affected by the gravity of others. There are around 550 moons in the solar system.
Parts of the Solar System
The solar system isn't just planets and the Sun. The majority of asteroids and comets are organised into one of these places:
ASTEROID BELTBetween the planets Mars and Jupiter is a ring of asteroids and the dwarf planet Ceres. They range from 329 million to 479 million km from the Sun. The width of the asteroid belt is about the same as the distance between the Earth and the Sun (about 150 million km)!
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KUIPER BELT and SCATTERED DISCThe Kuiper Belt is home to comets, asteroids, dwarf planets and dwarf planet candidates (objects that MIGHT be dwarf planets). Beyond Neptune, the Kuiper Belt is 4.5 billion to 8.2 billion km from the Sun, while the Scattered Disc extends to 16 billion km away. Objects in the Scattered Disc aren't affected by Neptune's gravity.
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OORT CLOUDThe farthest part of the solar system, the Oort Cloud is a huge sphere of comets and cosmic debris, leftover from the solar system's formation. It extends from 300 billion km to 15 trillion (15 000 billion) km from the Sun. It takes over one year for sunlight, traveling at 299 792.458 km/s, to reach the edge of the Oort Cloud.
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