Woooooah, check out that amazing night sky! What do you see?
You can probably spot thousands of stars in the sky at night, but did you know that they actually have a collective name? They’re part of the Milky Way Galaxy! Our planet, Earth, is part of it too, and so is the solar system that surrounds Earth.
But wait, hold up! What’s a galaxy exactly? Well, I’m glad you asked!
A galaxy is a massive collection of dust, gas, and billions and billions and billions of stars and solar systems (try counting them all – I dare you!). All of these things are held together by gravity, which is also what keeps your feet firmly planted on Earth.
Scientists think there could be around 200 billion galaxies, with some containing up to 100 TRILLION stars. One trillion is one million times one million, so that’s a lot of stars.
These galaxies come in all shapes and sizes, too. The Milky Way looks like a giant spiral or pinwheel. Some galaxies have the same spiral shape as ours, while others are shaped like ovals. There are even a few galaxies that just look like big splodges!
Galaxies are moving around all the time, so they can sometimes bump into each other every few billion years or so. You’d never feel it though, as our galaxy is so big. In fact, it measures 120,000 light years across, meaning it would take 120,000 years travelling at the speed of light to get from one end to the other! Phew!
I’m tired just thinking about how big our galaxy is, so I’m off for a much-needed rest! While I’m gone, why not try and count how many stars you can see in the night sky?
Solar system - a group of planets, moons and other things in outer space that surround the sun.
Gravity - a strong force that pulls things towards Earth (in other words, it stops you from floating into space!)
Speed of light - the distance that light can travel in a particular period of time.
Black hole - a big area in space where the gravity is so strong that nothing can escape!
1. Scientists think there could be around 200 billion galaxies.
2. The word ‘galaxy’ comes from the Greek word galaxias, which means “milky”.
3. Astronomers are still unsure of how black holes are formed.
1. What is the name of the galaxy that Earth is part of?
2. How many galaxies are there according to scientists?
3. Galaxies come in lots of shapes – name one of these shapes.
4. Our galaxy measures 200,000 light years across – true or false?
5. ‘Galaxias’ means milky – true or false?
Increase your knowledge by completing these activities.