Dara O'Briain’s ten AMAZING facts about space

Published on: 21 February 2018 Author: Dara O Briain

With his background in physics, Dara O'Briain is on a (space) mission to get children loving top facts about the the stars and planets and the universe and everything in it.    

So you want to become a space explorer? WHY?! (No, really – it's sort of a terrible idea.)

Still, there's something incredible about the idea of leaving our planet behind and setting out to explore the universe – there's so much we still don't know!

Here are my top ten AMAZING facts about space, for any budding space enthusiasts.

Beyond the Sky by Dara O'Briain is up for a Blue Peter Book Award

Fact one

Even starting a space journey is difficult, thanks to gravity. Gravity is a force – forces are how thing invisibly interact, and they can either PUSH or PULL. This sounds like a very complicated idea except that you’ve probably demonstrated this a million times; any time you’ve held magnets next to each other and seen them react!

Magnetism is a force and depending on which way you hold the magnet, it can PUSH the other magnet away, or it can PULL it closer. Things with lots of gravity pull things with less mass towards them. The Earth’s gravity attracts the Moon, which is why the Moon orbits (spins around) the Earth. The Sun’s gravity pulls on the planets, which is why they orbit the Sun.

Fact two

Officially, space starts 100KM (60 miles) above our heads. Which isn’t that far away. I live in London, so from my house, space is closer than the seaside!

Wherever you live, you’ll probably have travelled further than space to go on your holidays!

Fact three

The reason living things can survive on Earth and not on the Moon is because Earth has an atmosphere – a layer of gases that protects us from the Sun’s harmful rays, but also traps enough of the Sun’s heat to keep us warm. The atmosphere also gives us air to breathe, which is nice.

Fact four

The Moon is the farthest human beings have ever travelled in space and we haven’t done it often, or recently. Only 12 people have ever walked on the Moon’s surface.

Their footprints are still there – there isn’t any wind or rain (or any vacuum cleaners) to clean them up.

Fact five

Robots can explore planets we couldn’t physically survive going to, such as Venus and Jupiter, with their poisonous gases, acid rain and suffocating pressure. Unmanned probes can explore places too far away for humans to reach – space probes don’t get old or cold or thirsty or miss their families. And they DON’T complain about having to eat the same meals over and over again.

Fact six

The Sun is a star, just like all those other dots in the sky. Only this is our star and we’re pressed right up against it, so it lights up the whole sky (DON’T LOOK DIRECTLY AT THE SUN – seriously – it would really badly damage your eyes).

The sun is also, pretty much, the source of all the energy we’ve ever used on the planet. Not just the heat you can feel on your face, or what we take from solar panels, but also indirectly through plants.

Plants discovered long ago how to turn sunlight into fuel for growing. Then we eat the plants, or we eat the things that are the plants, and we get the energy.

Fact seven

The ancient Romans named Mars after their god of war because when you look at Mars from Earth, the planet looks red and a bit angry. But that’s not Mars’s fault – it’s the iron minerals in the soil that make it look red. But the Romans didn’t have a god of rust, so Mars it is.

Fact eight

Jupiter is more than twice the size of all the other planets in the Solar System put together, but it used to be four times the size of all the other planets put together – it’s constantly shrinking. That’s because of the way the planet is structured.

Unlike Mercury, Venus, Earth and Mars, which are mostly made of rock, Jupiter is mostly made of gas. The inner layers of hydrogen gas are extremely hot, as is its core, which is probably made of a mix of metal and rock. The planet’s outer layer of gases is much cooler though, and the difference in temperature between the hot core and the cool outer atmosphere makes the planet shrink – by 2 centimetres every year.

Fact nine

Saturn’s famous rings are made of chunks of ice and rock, some as small as pebbles, some as massive as mountains. They are what’s left of icy comets, asteroids and moons that were sucked in by Saturn’s gravity and smashed to pieces as they crashed into each other. They race around Saturn’s rings at different speeds – like giant joyriding snowballs, in a rush to get nowhere in particular. Some of the chunks of ice have formed moons.

Scientists have discovered up to 63 moons orbiting Saturn so far, but there may be more.

Fact ten

If you go outside and look up at the stars in the night sky, you are looking deep into our galaxy, the Milky Way. Every single star you can see with your naked eye is in the Milky Way. The stars in the other galaxies are just too far away for you to see without a telescope. 

The centre of the Milky Way is 30,000 light years away from Earth. The light from the stars you see there left them around the same time that Stone Age people were painting on cave walls.