My 3-year-old has been wondering where the cliff is – the one at the edge of the world. And she wants to know, if someone fell off it would they go floating out into Space…?
She’s not the first person to ask this question. People throughout history have wondered where the edge of the world might be and what would happen if you went there. Lots of explorers and scientists set out to measure the size and shape of the Earth and watched the stars and the Moon, and here’s what they discovered about the planet we call home…
Earth, the planet we live on, is about 4.5 billion years old. At least, scientists think that’s how old it is because of some really, really ancient rocks in Australia that come from about that long ago.
Since there was no-one around 4.5 billion years ago, we don’t know for sure how the Earth and the other planets in our solar system were made. But scientists who study stars and planets millions of miles away in Space have been able to do experiments to learn about how other galaxies (enormous collections of stars and planets) are formed. And they think this must be how our planet was made, too.
So let’s find out more about how the Earth got started…!
My 7-year-old says that humans are part of nature because we drink the same water as animals and plants. We eat and drink and wee and poo like animals. We grow our food in nature (and sometimes animals and birds eat it too). And we evolved from a common ancestor – a very simple creature that lived millions of years ago.
So what is ‘nature’? How are humans a part of nature? And what can we do to look after our natural world?
Storms are a kind of bad weather, usually made up of strong winds and rain or hail. They can cause lots of damage by blowing bits off buildings and trees, causing water to overflow from rivers and streams, or making huge sea-waves that crash onto the land.
Storms happen every year and are a normal part of the weather here on Earth. But some storms are stronger than others; the stronger the storm, the more damage it could cause. So, scientists have come up with a way to keep track of them – let’s find out how they do it…
A volcano is a large rocky structure on the surface of the Earth. Volcanoes look like hills or mountains but they can be quite dangerous because sometimes hot rocks and gases come spilling out from them. When volcanoes ‘erupt’ like this, they can cause lots of damage to things that are nearby.
But why do volcanoes erupt? And how are they made? If we want to understand how volcanoes work, we need to find out more about the structure of our planet, Earth…
My daughter was given a geology kit and has been busily tapping away with her mallet and chisel to release shiny semi-precious gems from large lumps of chalk. But what are minerals like these shiny gems made of, how do they form, and where are they found?
Air is mostly made up of a gas called nitrogen. But about one-fifth of the air (21%) is oxygen – the gas our bodies use when we breathe.
All living things need oxygen in order to stay alive but plants, algae and a group of bacteria called cyanobacteria, can also make oxygen. These plants, algae and cyanobacteria make more oxygen than they use and the extra oxygen goes back into the air. So, the oxygen is sort-of recycled, rather than used up.
Plants like trees use their leaves to make oxygen. But what if there were no trees left on Earth – would there still be enough oxygen in the air for us to breathe?