EARTH
The Earth formed from the gas and dust of a nebula 4.5 billion years ago.
Earth’s inner core is as hot as the surface of the Sun.
It spins on its axis at about 1,000 mph (1,600 km/h).
Seventy percent of Earth’s surface is covered in water. Most of this is salt water.
At the moment, Earth is the only planet in the universe known to support life.
How does
water shape
a coastline?
Find out on page 45How hard is
fluorite?
Find out on page 41EARTH