If you're used to seeing variations of Google Maps on everything from real-estate websites to Wi-Fi hotspot listings, the reason is because Google opened up the software to Google Maps with an API, which means "application programming interface." It allows software developers interact with Google Maps and use it to create new tools.
Although basic, it's a start. It has no identifiers on the map (labels, coordinate lines, constellation figures, etc.) other than some boxes that represent details about certain celestial objects, which are listed along the left side of the window. Zoom in on one and click on it to bring up a YouTube movie from the European office for the Hubble Space Telescope.
Just a hint of things to come, I'm sure.