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.

"Google has created an imaginative, powerful and unique tool, using modern technology to help people understand more about science. Think of it as an astronomical YouTube where people can upload their own views of the night sky."

The images used are all readily available from sources such as NASA, the Digital Sky Survey Consortium, the Palomar Observatory in California, and the UK Astronomy Technology Centre. User-generated images will also be made available as people start uploading pictures onto websites, and search results filter through in Google Earth.

Google Earth 4.2 is available for download now. The Google Earth + Sky function will be activated within 24 hours, Google said.

Layers

Seven Google-developed layers are available, along with a number of third-party creations. The layers are:

  • Constellations: from Cassiopeia to Andromeda, the Constellations layer connects the points of constellations through space, labelling each with its given name. You can learn about the stars that make up your favourite constellations.
  • Backyard Astronomy: The Backyard Astronomy layer lets you click through a variety of place-marks and information on stars, galaxies, and nebulae visible to the eye, binoculars and small telescopes. This layer is useful for amateur astronomers wanting to reference various fragments of the night sky.
  • Hubble Space Telescope Imagery: the HST layer provides you with some 120 high-resolution images provided by the Hubble Space Telescope, NASA/ESA's renowned orbiting telescope.
  • Moon: the Moon layer displays animations of two months of both lunar positions and moon phases.
  • Planets: the Planets layer shows the seven other official planets and their positions in the sky two months into the future.
  • Users Guide to Galaxies: the Users Guide to Galaxies layer enables you to go on virtual tours through different types of galaxies, from Ursa Minor Dwarf to the Milky Way.
  • Life of a Star: the Life of a Star layer takes you on a tour through the different stages of a star's life cycle.