The universe is really, really, really, really big



This is a picture of a small patch of sky, taken by the European Southern Observatory's Visible and Infrared Survey Telescope for Astronomy (VISTA). With the exception of a few stars, every single pixel of light in this image represents an entire galaxy, and you're looking at more than 200,000 of them.

That's 200,000 galaxies in this picture, not 200,000 stars, and each galaxy can contain anywhere from ten million to a hundred trillion stars. And this is only about 0.004% of the sky. The full-size image is a 250mb JPEG that's 17,000 x 11,000 pixels in size (download it here if you dare), but here's a sample of what the full-res looks like:
eso1213a_crop.jpg
It's easy to see a couple galaxies in this little sample section, but all of those tiny little red dots are galaxies too, each one with millions or billions or trillions of individual stars. They're small (and red) because they're very distant in both space and time, and looking at them now, we're effectively looking back at the creation of the universe.
For me, the most amazing thing about this image is what it implies about life elsewhere in the universe. No matter how improbable alien life might be, whether the odds are one in a quadrillion, or one in a quintillion, there are just so many stars (and as we now know, planets) out there in the universe that just running the numbers would suggest the existence of thousands upon thousands of worlds with life on them. So really, the odds are excellent that somewhere in this picture, behind one of those points of light, there's an intelligent alien civilization looking back at us. LINK
ESO, via Kottke