Beginner · 5 lessons
Astronomy Fundamentals
Build a mental map of the cosmos, from nearby worlds to the light arriving from distant galaxies.
- 1
Understanding the Universe
Astronomy begins with a useful distinction: the universe is everything physical, while the observable universe is the portion whose signals can reach us.
About 2 minutes reading · Beginner - 2
Earth’s Place in Space
Your address in the cosmos connects daily sky motion to Earth’s rotation, its orbit and its location inside a galaxy.
About 2 minutes reading · Beginner - 3
The Solar System
Our planetary neighborhood formed from shared material, yet its worlds have very different surfaces, atmospheres and histories.
About 2 minutes reading · Beginner - 4
Gravity and Orbits
An orbit is continuous free fall with enough sideways motion to keep missing the central body.
About 2 minutes reading · Beginner - 5
Light, Distance, and Cosmic Scale
Light carries both information and a time delay. Learning to separate distance, brightness and wavelength makes astronomical images much more useful.
About 2 minutes reading · Beginner
Put the ideas together
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