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.
Stellarium key features:
- Realistic simulation of the sky, sunrise and sunset
- Default catalogue of over 600,000 stars
- Downloadable additional catalogues for up to 210 million stars
- Catalog data for all New General Catalogue (NGC) objects
- Images of almost all Messier objects and the Milky Way
- Artistic illustrations for all 88 modern constellations
- More than a dozen different cultures with their constellations
- Solar and lunar eclipse simulation
- Photorealistic landscapes (more are available on the website)
- Scripting support with ECMAScript (a few demo scripts are included)
- Extendable with plug-ins: 8 plug-ins installed by default, including:
- artificial satellites plug-in (updated from an on-line TLE database)
- ocular simulation plug-in (shows how objects look like in a given ocular)
- Solar System editor plug-in (imports comet and asteroid data from the MPC)
- telescope control plug-in (Meade LX200 and Celestron NexStar compatible)
New features in version 0.16.0:
- RemoteSync plugin, which allows running several connected instances of Stellarium.
- Non-spherical models for solar system objects like asteroids and small moons.
- Solar system config file is now split into two parts.
- AstroCalc feature extension: What's Up Tonight, graphs, ...
- DSO: Addition of catalogs of peculiar galaxies
- New Skycultures: Belarusian, Hawaiian Star Lines
- Telescope plugin: support for the RTS2 telescope system.
- Location can now be read from a GPS device. [full release notes]