Astronomy Q&A: Science- and Hobby-Based Questions and Answers

What’s a black hole? What will a larger aperture telescope get you? This is the place to come for answers to almost every astronomy question you can think of — and many you haven’t.

Science-Based Q&A

Deepen your knowledge of astronomy as a science as you browse these Q&As and learn about the universe’s fascinating array of celestial bodies, from planets to stars to black holes. Discover the difference (and evidence for) dark energy and dark matter, and learn about worlds closer to home such as Venus and Saturn.

Solar System



Comets, Asteroids & Meteors



Milky Way

Black Holes


By Wavelength

Astronomy & Society

The Kavli Foundation Q&As

Hobby-Based Q&A

Delve into the hobby of astronomy: learn about different types of equipment and what they can do, and discover the limits (read: challenges) of observing the night sky with instruments and the unaided eye. The Q&As presented here cover a wide range of readers' questions, and we’ve responded with detailed and well-researched answers. Search for a specific question or just browse through — our readers have come up with some interesting hypotheticals over the years!

If there’s a question that hasn’t been asked, ask it yourself by sending a note to

General Observing

Observing the Sun

Observing the Moon

Observing Satellites

Observing the Planets

Observing Comets, Asteroids & Meteors

Observing Stars


Astronomy Equipment


Amateur Telescope-Making

Eyepieces / Optics



Questions on S&T Articles

Sky Atlas Questions

Math Questions

Really, Really Miscellaneous Questions