Celestia is a space simulation program developed by Chris Laurel. It was initially released on 2001. This 3D astronomy application allows users to explore the universe in 3D. It shows and interacts with astronomical objects in various scales, may it be an entire galaxy or a small spacecraft. The program also shows the HIP, or HIpparcos Catalogue, of over 100,000 stars. Using the VSOP87 planetary orbits theory, Celestia is capable of providing lunar and solar eclipse finder as well as displaying the orbital paths of comets, moons, asteroids, dwarf, artificial satellites, spacecrafts, and planets.
Changing the number and styles of the stars to be displayed is possible. There is also a function to change the look of the viewpoints at any angle. The program can also be used to adjust the field view as high as 3.4 seconds of arc and as wide as 120 degrees. It offers time simulation as well, which can be used to set the universe’s view in the past or the future. The program can also show the positions and names of different space objects such as star clusters, stars, galaxies, comets and more. Other details that the program displays include the object’s distance, radius, average blackbody temperature and more.
Extending the functionality of Celestia is possible by adding new objects. Add-ons as well as third-party applications may also be installed.