Khan Academy Science
by Khan Academy · Khan Academy
Comprehensive free science education platform covering physics, chemistry, biology, and astronomy with interactive exercises and video tutorials.
More resources on Astronomy
SciShow
Accessible science news and education covering biology, chemistry, physics, and earth science with engaging hosts.
Kurzgesagt - In a Nutshell
Beautifully animated science explanations covering astrophysics, biology, philosophy, and speculative scientific concepts.
CrashCourse Science
Engaging video courses covering physics, chemistry, biology, astronomy, and ecology with clear explanations and animations.
stellarium.org
Stellarium is a free, open-source planetarium software that realistically simulates the night sky for any location and time, with stars, planets, constellations, and deep-sky objects. The site offers download links, documentation, tutorials, and information about features.
Heavens-Above
Satellite passes and sky info
In-The-Sky.org
Events and sky charts