The Solar System is a very exciting place. Much of it is still unknown to us and we discover new things about it every day. As technology is advancing so is our ability to see further into this amazing space that surrounds our planet. Here are some great facts about Earth’s neighbourhood.
- The Solar System is 4.6 billion years old! There are many theories on how the Solar System came to be. Unfortunately no one was here to see how it was created so we can only look at the science and figure out for ourselves what makes sense.
- The most popular idea for the creation of the universe is the Big Bang Theory. To put it simply this is the idea that 14 billion years ago the universe was just a tiny space. This space was very hot and dense. All of a sudden this space expanded very quickly like an explosion sending pieces of the universe, space and time all over space. All of these things are still growing today as our universe continues to change.
- The Solar System is classed as the Sun and all objects that go around it, controlled by the Sun’s gravity. This includes planets, asteroids, moons, comets and many more! The bigger the object is, the more gravity is has, because the Sun is so huge it has enough gravity to hold all these items in orbit. Some are tiny but some that aren’t even classed as planets are bigger than the planet Mercury, for example Jupiter’s moon Ganymede.
- As of 2015 there are 8 planets and 5 dwarf planets in the Solar System. In order of distance from the Sun these planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. The dwarf planets in order of distance from the sun are Ceres, Pluto, Haumea, Makemake and Eris.
- There are four inner planets called the terrestrial planets. These are Mercury, Venus, Earth and Mars. These are made up of metal and rocks and have a very heavy core. They tend to have surfaces marked with crater, valleys, mountains and volcanoes. These things make them very different to the outer planets.
- There are four outer planets called the gas giants. These are Jupiter, Saturn, Uranus and Neptune. These tend to be larger than the four inner planets and have very thick atmospheres full of gas such as hydrogen and helium. Jupiter and Saturn are almost entirely made of these gases whilst it only forms the outer layer of Uranus and Neptune. It would be almost impossible to land on these planets as they only have a very small solid core, the rest of the planet is made up of stormy gases and severe temperatures.
- There are five dwarf planets and probably more to be found! These are Ceres, Pluto, Eris, Makemake and Haumea. A dwarf planet is an object that goes around the Sun (this is called orbiting), is big enough to make a large roundish shape, does not move items out of its orbit path and is not a moon. Scientists believe there could be hundreds more waiting to be found.
- Between Mars and Jupiter there is an asteroid belt. This is a section of space filled with millions of oddly shaped asteroids. They go around the sun in the space between Mars and Jupiter’s orbit path. Scientists think it is likely that these asteroids were either unable to form a planet, or are pieces of a planet that broke apart long ago. One of the objects in this area is the dwarf planet Ceres.
- Beyond the orbit of Pluto is the Kuiper Belt. This is similar to the asteroid belt. It is a disk shaped area that goes around the Sun filled with small space objects. However instead of asteroids the Kuiper Belt mostly contains objects that are made out of dust and frozen gases. These are called comets. Every so often one of these will lose its place in orbit and be thrown back towards the Sun. These can sometimes be spotted from Earth as they melt into a ball of light. The Kuiper belt is also 20 times bigger than the asteroid belt.
- Outside of the Kuiper Belt is an area called the Oort Cloud. This area is sort of like a huge cloud containing more icy objects and comets. The area does not rotate around the Sun, this is thought to be because the Sun is so far away, its gravitational pull is not as strong as other large stars surrounding the Oort Cloud.
- In ancient times people were unaware of the Solar System. It was actually believed that the Earth was the center of the universe and that all objects orbited around us!
- Several very intelligent astronomers and scientists created the new sun centric model. The helped to explain how the Sun is the center of the universe and its huge amount of gravity causes all other items in the Solar System to travel around it. The names of these astronomers are Nicolaus Copernicus, Galileo Galilei, Johannes Kepler and Sir Isaac Newton.
- Most of the Solar System’s mass is contained in the Sun. It is so big that it makes up 99.86% of the Solar System! The other big planets, Saturn and Jupiter make up for most of the rest. Compared to these, other planets like Earth and Mars are very small and make a up for a very tiny percentage.