How Do We Search For Other Planets?

A graphic showing los of cartoon planets, the numbers 1992 and 5000

What is a light year?

Investigate: Measure the Size of a Galaxy

Have you ever wondered how big a galaxy is? They contain millions to billions of stars but what does that really mean for size?

Reading about sizes in a book is one thing, but what if you could make an observation of a galaxy and then measure its size?

Picture of a galaxy with a ruler next to it and question marks

What is the Sun?