Celestia is a free real-time space simulation that lets you experience our universe in three dimensions.

Unlike most planetarium software, Celestia doesn't confine you to the surface of the Earth. You can travel throughout the solar system, to any of over 100,000 stars, or even beyond the galaxy.

All travel in Celestia is seamless; the exponential zoom feature lets you explore space across a huge range of scales, from galaxy clusters down to spacecraft only a few meters across.

A 'point-and-goto' interface makes it simple to navigate through the universe to the object you want to visit.

Changes in Current Version:

* Integrated more of Grant Hutchinson's corrections for the orientations of
solar system bodies
* Updates for asteroids and comets from Grant Hutchinson:
- Added Phil Stooke's textures for the asteroids Ida and Gaspra
- Fixed mirror-reversal of Ida and Gaspra meshes (Grant Hutchinson)
- Use orbital elements valid for the Galileo encounters of Ida and Gaspra
- Corrected rotation parameters
* Made name matching for galaxies case-insensitive
* Corrected orbits of Uranians satellites Miranda, Ariel, Umbriel, Titania and
Oberon.
* cel:// URL fixes
- Added support for relative URLs
- Improved drag and drop support on Windows
- Browser integration on Windows: clicking on a cel:// URL launches Celestia
- Better time precision
* Added new keyboard commands for dealing with light time delay
- ? : show light time delay between current position and selected object
- - (minus) : compensate for light time : subtract light travel time to
selected object from the current time
* KDE interface: add subtract light time button to Set Time dialog
* Added cubic interpolation option for sampled trajectories (.xyz files)
* Added NormalMap field for .ssc files
* Prevent crashing when CompressTexture true is specified for an already compressed texture.
* KDE: Implement eclipse finder
- Eclipse finder code separated into UI and platform-independent parts
* Added basic support for rendering nebula as 3ds meshes.
* Modified format of galaxies file to handle other deep sky objects as well
* Added OpenCluster objects
* Implemented 'markers'
- Selection is highlighted with a marker
- Markers may also be set on objects using the right-click context menu
- Added mark/unmark commands for scripts
- Bound Ctrl+K to toggle display of markers
- Added flash messages indicating on|off status of markers
- Implemented markers into KDE interface
* Added triangle-accurate picking of mesh objects
* Multiview
- Ctrl+R : split view vertically
- Ctrl+U : split view horizontally
- TAB : cycle active view
- DEL : delete active view
- Ctrl+D : delete all views except active one
- Views may be resized by dragging on borders
- Multview functions also available in the view menu
* Eliminated eclipse shadows appearing on wrong side of planet
* Added support for specular and bump map effects across a wider range
of graphics hardware.
- Introduced notion of a render path
- Ctrl+V changed to cycle render path instead of toggle vertex shader
- Added IgnoreGLExtensions directive for celestia.cfg
* Added track command for script
* Fixed eclipse shadow z-fighting artifacts
* Fixed vertical mirroring of textures on 3DS models
* Fixed problems with bump mapping
* Enabled loading of .cel scripts through the Windows or KDE shell
* New directory structure for add-ons; meshes, textures, and other media
may now be located withing an add-on subdirectory.
* Added texture for Eros
* Added separate cloud and surface textures for Venus
* New "invisible" class for solar system objects
* Fixed crashes that occurred when viewing ringed planets on older hardware
* Got rid of three zeros after decimal point when displaying time rate
* Updated configuration files for new versions of autoconf