Sunday Science: Galaxies


Now there is a BIG topic.
The basic definition of a galaxy is a system of millions or billions of stars, together with gas and dust, held together by gravitational attraction.

Earth is a part of the Milky Way galaxy, which is one of hundreds of billions of galaxies in the Observable Universe.
But just how big is a galaxy?  Our galaxy is roughly 100,000-120,000 light years in diameter.

Wow, thats pretty big, you say?

Well, for comparison, the largest known galaxy, IC 1101, is estimated to be 5.5 MILLION light years wide.
That’s equal to 50 Milky Way galaxies side by side.

Like I said, it’s a big topic.

Jason Major wrote an article about the size of the galaxies over at, and included a  galactic comparison chart by Rhys Taylor that will make you feel very tiny.

Go learn more about our Universe!  It does a body good!

Leave a Reply

Your email address will not be published. Required fields are marked *