solar spacecraft

satellites and rockets

what do satellites do?

GEO satellites

LEO satellites

polar orbits

GPS satellites

LEO satellites

LEO stands for Low Earth Orbit and low means 'low for a satellite'! We say a satellite is in an LEO when it orbits somewhere between 300 and 800 km above the Earth's surface. These satellites travel very fast. At a speed of nearly 28,000 kilometres an hour, a complete tour around the Earth takes only about 90 minutes.

Image of the globe with lots of tiny objects all around it

There are now estimated to be nearly 8,000 objects more than 10 cm across in LEO. Much of these are space junk left over from discarded rockets and spacecraft. Here is a picture showing objects which we know are in LEO.

Image of the Hubble telescope

LEO satellites can collect data about the oceans for climate and ecological studies or they can survey the land in the hunt for minerals and oil. They also provide a useful way to check the destruction of forests. LEO is used for military spy satellites to keep a watchful eye on other countries. The Hubble Space Telescope and the International Space Station are also in LEO so these satellites can look up as well as down.

Satellite image of the Ganges LEO satellites are excellent for making detailed observations of the Earth.

This is an image from NASA's LANDSAT satellite of the Ganges river delta of Bangladesh and India. This delta is covered with swamp forest, called Sundarbans, and is the home of the Bengal tiger.

Take a look at these other beautiful images from LANDSAT: The Tigris river delta and the Nile.