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What is
the
solar system?
It is our Sun and everything that travels around it. Our solar system is
elliptical in shape. That means it is shaped like an
egg. The Sun is in the centre of the solar system. Our solar system is always in
motion. Nine known planets and their moons, along with
comets,
asteroids, and other space objects
orbit the Sun. The Sun is the biggest object in our
solar system. It contains more than 99% of the solar system's
mass.
Astronomers think the solar system is more than 4
billion years old.
The words " solar system" refer to
the Sun and all of the objects that travel around it. These objects include
planets, natural satellites such as the
Moon, the asteroid belt, comets, and
meteoroids. Our solar
system has an elliptical shape and is
part of a galaxy known as the Milky
Way. The Sun is the centre of the solar system. It contains 99.8% of all of the
mass in our solar system.
Consequently, it exerts a tremendous
gravitational pull on
planets, satellites, asteroids, comets, and meteoroids.
Astronomers believe the
solar system formed 4.5 billion years ago. However, they differ in their beliefs
about how the system formed. Some believe the whole solar system formed from a
single flat cloud of gas, while others believe it formed when a huge object
passed near the Sun, pulling a stream of gas off of the Sun. Astronomers
theorize the planets then formed from this gas stream.
Our solar system is made up of a star – the Sun – nine
planets, more than 120 moons and a bunch of comets, asteroids and other space
rocks. The nine planets are
Mercury,
Venus,
Earth,
Mars,
Jupiter,
Saturn, Uranus,
Neptune and
Pluto.
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