Today, we believe that ALL STARS HAVE PLANETS. Whoah. Speaking of which:
I LOVE THIS CHART SO MUCH:
Click the image to see the full-size version. Tip: The hover-text really extends the image's sensawunda factor.
For your viewing pleasure and to help visualize the scope of our galaxy, I offer the Andromeda Galaxy, M31. It's the closest spiral galaxy to our own Milky Way, in terms of both size and distance:
Click the image to see the NASA photo.
Just imagine all those stars orbited by their own solar systems, perhaps cradles to other civilizations. How many are out there?
On a related note, want to read a snippet from the Prologue of Adventures of Jack and Stella? Here you go:
The Milky Way Galaxy, as the humans call it, is a barred-spiral whose glowing arms span the endless emptiness of space for about 30,000 parsecs, or 100,000 light-years (or 600 trillion human miles). It is shaped like a disk: Viewed edge-on, it is only a hundredth as thick as it is wide, just 300 parsecs or 1000 light-years (or 6 trillion miles) thin. Within those arms shine more than 300 billion stars, each a sun warming rocky debris beyond measure, thousands of comets, and a handful of planets – some of which are ringed by great disks of ice and rock, and many orbited by moons like miniature solar systems of their own. The Milky Way is slightly larger than the average galaxy, of which more than 100 billion populate the universe.
I hope that helps give a sense of the scope of these things, and just how many planets are whirling around their parent stars, out there in the dark.
(Yes, word-count went down from revisions and then back up. So it goes.)