Stars

Why stars cannot form on their own

Physical limits that make star formation very difficult

How many stars can be seen with an unaided eye?

How many stars can be seen with an unaided eye?

How long did it take for light from the stars to r...

A discussion on the speed of light, travel of light, and distances to stars in the universe

What is the purpose of the Sun?

What is the purpose of the Sun? How vital is it for life on our planet?

The nearest star

What is the closest star to us, how far is it, and what do we know about it?

Sun's energy output and how we're protected from i...

Mechanisms at work on the Earth that protect us from our Sun

What's a Globular Cluster?

Definition and brief explanation of what a globular cluster is.

What is a pulsar

What is a pulsar

What are quasars

What are quasars and what makes them different