Our Pythes Smartmedia series is intended to make you smarter by explaining the world. If you want to learn all the basic knowledge, this series is perfect for you.
In this episode we discuss planet Earth.
The earth is a huge ball of rock spinning in space.
It is not a perfect ball, as it is slightly flattened at the top and bottom.
The equator is an imaginary line around the widest part.
The top half of the Earth is called the northern hemisphere and the bottom half is called the southern hemisphere.
The Earth measures about 40000 kilometer around the equator. It would take a month to drive around it at 55km per hour.
The Earth weighs about 6000 million million million tonnes.
The hottest place is the Sahara Desert, in Africa, where it is hot enough to fry an egg on the sand.
The lowest temperatures are in Antarctica, the South Pole, the coldest and windiest place in the world.
Only about a quarter of the Earth surface is land. There are seven big pieces of land, called continents. Most of the land is in the northern hemisphere.
About one fifth of the land is desert. Deserts are the hottest and driest places on Earth. They have less than 250mm rain per year.
Nearly three quarters of the Earth’ s surface is covered by sea. The four oceans are all joined together. You could sail around the Earth without seeing land.
Near the equator it is hot all year round and it rains nearly every day. The land around the equator is called the tropics.
Thick green forests called rainforests grow in the tropics. Tropical rainforests contain over half of all the types of plants and animals in the world.
Many mountains are too high and cold for plants and animals to survive there. Mount Everest is the highest mountain on Earth: 8850 metres tall.
A small part of the Earth’s surface is always covered with ice. The further you travel from the equator, the colder it can get. The Poles are the coldest places on Earth.
The Earth is surrounded by a layer of air about 500 kilometres thick, called the atmosphere. It stops dangerous rays from the Sun burning up life on Earth.
We cannot see air but we feel it as wind. It is made up of many gases, such as oxygen, which we breathe, and carbon dioxide, which is used by plants. Plants also create the oxygen, making plants very important for us to stay alive.
The higher you go into the atmosphere, the less air there is and the harder it is to breathe. That is why people carry oxygen tanks when they climb mountains.
All our weather happens in the first twelve kilometres of the atmosphere. Above this, there are no clouds, and the Sun always shines in the daytime. Aircraft usually fly higher than the weather, about 13 to 22 kilometres above the Earth.