Information, beautiful-looking images of galaxies far, far away and celestial constellations such as Andromeda and Cassiopeia are now available for free on your computer, thanks to Google.

The latest version of Google Earth was launched today. Google Earth + Sky lets you look out from Earth into space, as well as the other way around, enabling you to search 3D images of space.

"The basic idea is to take Google Earth and turn it on its head," Ed Parsons, geospatial technologist at Google, told Tech.co.uk at a briefing at Google's London HQ this morning.

"Only about 25 people have ever seen the Earth from outside, and we wanted to give more people the opportunity to do that."

100m stars, 200m galaxies

Aimed at amateur astronomers, Google Earth + Sky features some 100 million stars, around 20,000 of which are searchable for more information such as their name, location, history and age. Images of 200 million galaxies are also featured.

Google Earth + Sky features a selection of optional layers which allow you to see images taken from the NASA's Hubble Space Telescope as well. You can see also images of lunar cycles taken over the course of two months. And you can get other information - about galaxies and constellations, for example - relating to that particular view of the night sky.

The application works in the same way as Google Earth in that you enter a start position, for example where you live. You can zoom in on an area from where you want to view the night sky.

"Click a button and the world flips round and you see the sky from that particular location," Parsons explained. "The view would be the constellations that you would see oriented in the sky on that particular day at that particular time."

Light pollution

For those of us living in urban areas, problems with unclear night skies and light pollution mean we rarely get to see more than a few stars in the night sky. The new Google Earth application means we can get a clear glimpse at the sky on our computers.

"This initiative will open a new window for anyone to be able to appreciate, explore and discover our fragile position in this vast and amazing universe," said Dr Francisco Diego, from the Department of Physics and Astronomy at University College London.