Free/Open-source Astronomy Software
Astronomy, considered as one of the oldest sciences, is the scientific study of celestial objects (such as stars, planets, comets, and galaxies) and phenomena that originate outside the Earth's atmosphere (such as the cosmic background radiation).
With the aid of powerful telescopes, Astronomers were able to study our vast skies. Since accurate and reliable software related to Astronomy are plenty these days, anyone can now have an opportunity to learn more about Astronomy without the need for telescopes.
I’ve collected here a list of well-recognized free/open-source Astronomy software. I hope this helps: