WorldWide Telescope (WWT) is a virtual telescope to astronomers, a virtual observatory of the Earth researchers as well as teaching and learning tool to science educators. It was initiated at 2006. You can view sky or universe at our home screen.
Its provides us feeling of journey in universes. We can travel across the universe as we are traveller of universes. Click on Image to navigate ourselves. And mouse will become navigation throttle. We can zoom or Shrink the size of any galaxy or any Solar system.
Even we can watch our home land, Earth, Zoom and take enjoy of the top view of Earth Surfaces.
Click here to view Live “Web Control ”
Most Interesting part for use, is that it comes with Development option for new and passionated developer. Its include its own SDK to develop such application. You can refer ref  for further details.