Alternatives to Celestia
An open-source real-time 3D space simulator for exploring the solar system, stars and galaxies. The listings below can replace it for an important use case. Each note says what changes if you switch.
The original
Celestia
An open-source real-time 3D space simulator for exploring the solar system, stars and galaxies.
Replacements
Listings that take over the same core job as Celestia.
SpaceEngine
A 3D universe simulator for travelling between stars and galaxies and landing on planets.
SpaceEngine is paid, closed-source and Windows-only, adding seamless travel to planetary surfaces and procedurally generated star systems alongside real catalogued objects.
Universe Sandbox
A physics-based space simulator for experimenting with gravity, collisions, climate and stellar evolution.
Universe Sandbox is paid software for Windows, macOS and Linux that adds N-body gravity simulation, collisions and a climate model instead of pure exploration.
Stellarium
A planetarium on your screen showing exactly what is in the sky above you, tonight or on any date you choose.
Stellarium is an open-source GPL-2.0 planetarium showing the sky from a chosen location and date, adding Android and iOS versions and telescope control.
KStars
A free, open-source desktop planetarium from KDE for simulating the sky and planning observations.
KStars is a free open-source KDE desktop planetarium focused on sky simulation, observation planning and astrophotography rather than free flight between galaxies.
Similar software
Related functionality, not a direct replacement.
Google Earth
A free 3D globe with high-resolution imagery, historical imagery layers and guided Voyager stories.
NASA Worldview
A browser tool from NASA for exploring full-resolution daily satellite imagery of the whole globe.
Marble
A KDE virtual globe and world atlas that zooms from a desktop globe to OpenStreetMap street level.
PhET Interactive Simulations
Free interactive physics, chemistry and math simulations usable directly in the browser.
