WorldWide Telescope

WorldWide Telescope is a sky viewer that stitches together real telescope imagery into one pannable, zoomable view of the heavens. In the web client you drag across the sky, zoom into a galaxy or nebula, and watch the picture resolve from a smudge into a detailed image. Guided tours walk you through highlights and explain what you are looking at.

The project began at Microsoft Research and is free to use. The draw is that it uses actual survey and observatory images, so zooming in is not a trick; you are moving through genuine data about the sky.

Take a tour first if you are new, then switch to free exploration. It runs in the browser, including on mobile, though a bigger screen helps. It is a good companion to /site/stellarium-web, which shows the sky as the naked eye sees it. More at /category/science-space.