WHERE DOES THE SKY BEGIN?

Take a look up, past the tops of the trees and the roofs of the houses. The sky seems to go on, up and up, forever! But what is the sky, and where does it begin?

Our planet, Earth, is surrounded by a layer of gases called the atmosphere.

These gases are held in place by the planet’s gravity, and they help make life on Earth possible.

The atmosphere gives us the oxygen we need to breathe and protects us against dangerous radiation that comes from the sun. It also acts like a blanket, trapping heat from the sun’s rays and keeping Earth’s surface warm enough for us to survive. This is called ‘the Greenhouse Effect’.

So when you look up into the sky, you are looking up into this clear mix of gases called the atmosphere that starts at the Earth’s surface. Really, the sky is all around you!

EXOSPHERE (600 – 10,000 km)

THERMOSPHERE (85-600 km)

International Space Station (page 64)

The

MESOSPHERE (50 to 85 km)

Spacecraft Satellites (page 64)

International Space station to be added

Satellites (page 64)

The Northern Lights (page 74)

Meteors

STRATOSPHERE (14.5 to 50 km)

Jet planes (page 32)

TROPOSPHERE (up to 14.5 km)

Storms (page 70)

Clouds (page 14)

Light aircraft