Stellarium (open source)

Main features:
Sky

* default catalogue of over 600,000 stars
* extra catalogues with more than 210 million stars
* asterisms and illustrations of the constellations
* constellations for ten different cultures
* images of nebulae (full Messier catalogue)
* realistic Milky Way
* very realistic atmosphere, sunrise and sunset
* the planets and their satellites

Interface

* a powerful zoom,
* time control
* scripting to record and play your own shows
* fisheye projection for planetarium domes
* spheric mirror projection for your own dome
* graphical interface, extensive keyboard control, telescope control

Visualisation

* equatorial and azimuthal grids
* star twinkling and shooting stars
* eclipse simulation
* skinnable landscapes, now with spheric panorama projection

Customisability

* add your own deep sky objects, landscapes, constellation images, scripts.

DOWNLOAD

Here for Windows

Here for Linux

Here for Mac