There are different educational applications on the internet and one of the most interesting is Stellarium. This open-source project that is distributed freeware allows users to benefit from a lot of features that will transform a computer into a virtual planetarium, where a lot of facts can be learned. The sky catalog of this application features more than 200 million different stars, with many more of them being added constantly by dedicated members of the community. Users can start a virtual trip to any of these stars and find out whatever information is known, such as size, mass, temperature or distance from Earth.

Constellations are known for thousands of years and with the aid of this tool, users can also learn how to identify any of them in the night sky. The app provides both northern and southern hemisphere night skies and besides the standard view, users can also opt to discover what are the constellations of twelve major cultures of the world. The Milky Way is designed in a realistic manner and users have the possibility to learn a lot of facts, by either reading short or long articles related to this galaxy.

A fisheye projection mode is also available within the tool, in order to replicate the atmosphere of a planetarium dome and multiple keyboard shortcuts have been added in order for users to easily control their space trip. The interface is also much simple and it can also be hidden for users to see more of the night sky, for example. There are different simulations available, such as that of an eclipse or of a supernova. Plugins can also be added into the application and they provide much more content than the already comprehensive app. They can also be installed for free, thanks to the user community.