Stellarium

Stellarium is a free open source planetarium for your computer. It shows a realistic sky in 3D, just like what you see with the naked eye, binoculars or a telescope.

It is being used in planetarium projectors. Just set your coordinates and go.

Features in version 0.11.0:

sky

* default catalogue of over 600,000 stars
* extra catalogues with more than 210 million stars
* asterisms and illustrations of the constellations
* constellations for twelve 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
* multilingual interface
* fisheye projection for planetarium domes
* spheric mirror projection for your own low-cost dome
* all new graphical interface and extensive keyboard control
* telescope control

visualisation

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

customizability

* plugin system adding artifical satellites, ocular simulation, telescope configuration and more
* ability to add new solar system objects from online resources...
* add your own deep sky objects, landscapes, constellation images, scripts...