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Beyond our Solar System: - The Universe

For thousands of years humans have been trying to understand what mysteries lay beyond our planet Earth.

The Universe is so big that it is difficult to imagine it.

Here are some amazing universe facts

  • Astronomers study the stars. Galileo, (Italian) was the first astronomer to study the stars through a telescope?

  • What is a star? – Stars are huge glowing balls of gases that give out large amounts of light and heat energy. There are billions of billions of stars in the Universe.

  • Why can’t we see stars during the day? - We cannot see the stars during the day because the light they give out is very faint compared with the light from the Sun.

  • Why does the Sun look much brighter than the other stars? - The stars you see at night do not seem very bright because they are much further away than the Sun. The stars are all around us.

  • Why do the positions of stars appear to change when you view them from the Earth? - If you watched the stars all night, they would seem to move across the sky. This happens because the Earth is spinning on its axis as it orbits the Sun

  • Galaxy - What is a galaxy? – A large group of stars is called a galaxy. The Sun is in a galaxy called the Milky Way. There are millions of other galaxies, and each of these galaxies contains millions of stars. All these galaxies make up the Universe.

  • Constellation – are patterns of stars in the sky. They were named after ancient gods, heroes and animals. There are over 88 constellations over the whole sky.

  • Red giants are older stars that have swollen up or puffed outwards as a fiery mist. They could blow up or fade away depending on the size it becomes. Red giants are many times more luminous that the Sun due to their large size.

  • White Dwarf is a dying star - A star that has burnt off or is a dying star. It is like the Sun and once it has used up its nuclear fuel it becomes a white hot dense core that remains.

  • Supernova or nova is an exploding star which erupts almost overnight. Novae occur in our Galaxy every year and can be seen with the naked eye however, a supernova is much more violent and rare.

  • Pulsar – is what is left after a supernova explosion. What is left is a very hot ball of matter, spinning at a tremendous rate. It sends out a beam of light or radio waves like a search light which appears to pulse on and off.

  • Falling stars or shooting stars – are not stars they are tiny space rocks that enter Earth’s atmosphere and burn up creating amazing streaks of light seen in the night sky. They are caused by bits of rock called meteoroids and the trail of light that the burning meteoroid produced is called a meteor. If any of this meteoroid hits the Earth, the remaining part is called a meteorite.

  • The distances between stars are so large that they are hard to imagine. Scientists measure these distances in light years. One light year is the distance travelled by light in one year.

  • The nearest star to the Sun is called Proxima Centauri. It is 4.22 light years away. It would take a rocket from Earth over 12,000 years to reach Proxima Centauri.

  • Light years measure distance. It is the distance that light can travel in one year.

  • When you look at stars on a clear, dark night some appear to twinkle. This happens because the light from the stars has to travel through the Earth’s atmosphere. Air currents bend the light, and make the stars twinkle.

  • Dark Matter – cannot be seen but scientist know that it is out there.

  • Comets – are a cluster of dust and ice with a big tail, often referred to as ‘dirty snowballs that float through space. They are left over from the formation of stars and planets from billions of years ago.
  • Challenge yourself on the Universe to see what you know. 
    Go to the Universe Quiz page -  click here

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