Stellarium is a free planetarium app that shows a realistic sky in 3D, just like what you can see with the naked eye, binoculars or a telescope. The app uses OpenGL to render a 3D photo-realistic skies in real time. Download Stellarium for Windows, Linux and Mac OS.
Stellarium shows a realistic sky in 3D with elements like stars, constellations, planets, nebulas and others things like ground, landscape, atmosphere, etc. You have an ability to add new solar system objects from online resources. You can also add your own deep sky objects, constellation images, landscapes, scripts. The available plugin system adds ocular simulation, artificial satellites telescope configuration and much more.
The default catalog of Stellarium contains over 600,000 stars, but if you like you can install extra catalogues and extend the base to more than 210 million stars. Stellarium has also access to asterisms and illustrations of the constellations for eleven different cultures, images of nebulae (full Messier catalogue), realistic Milky Way, very realistic atmosphere, sunrise and sunset, the planets and their satellites.
Stellarium offers option like powerful zoom, time control, fisheye projection for planetarium domes, spheric mirror projection for your own low-cost dome, extensive keyboard control, telescope control, equatorial and azimuthal grids, star twinkling, shooting stars, eclipse simulation or even skinnable landscapes with spheric panorama projection. The app is free and ready for universe explorers.