Google has just released a new version of its Google Earth software — one that lets you look up to the sky instead of down to the ground. It’s essentially a consumer-grade Virtual Observatory, like the UK AstroGrid, the US National Virtual Observatory and the Euro-VO project.

It’s not so obvious when you fire it up and are presented with little icons for various stars and galaxies, but the underlying data is a continuous picture of the sky, although the resolution depends on what data exists in a given area. For example, type in “HDF” and it takes you to the Hubble Deep Field North, one of the deepest images ever taken of the sky, showing galaxies in every stage of their evolution. Conversely, however, most of the objects don’t have any information attached to them at all — just fuzzy blobs.

Of course, real astronomers would require a lot more information: how was the data taken? At what frequency? It would certainly be great to be able to use this as a front-end to the “real” Virtual Observatory like AstroGrid. These science-oriented projects have spent a considerable amount of time and effort refining their interface, but just don’t have the funds or expertise of a company like Google. And now I’m just waiting for someone to implement a layer showing the Cosmic Microwave Background and other “diffuse” sets of data on the sky. (Update: my very bright grad student, JZ, has figured out how to import CMB data as an image into the program.)

Update 2: VO/Blogger Alasdair Allan has started to work out how to connect Google Sky to the Virtual Observatory via the PLASTIC protocol. Alasdair was also interviewed about Google Sky for the Guardian’s science podcast.

Update 3: See the comments for information on Sky-Map, a web-based project very similar to Google Sky, as well as a pretty complete dataset showing the microwave sky.