The image above is as baffling as it is gorgeous.
First, kudos go to my pal Rogelio Bernal Andreo, who took this magnificent shot. It shows the Andromeda galaxy, the closest big spiral galaxy to our own, and in fact the other big member of our neighborhood galaxy minicluster called the Local Group. At 2.5 million light-years away, it’s bright enough to see with the naked eye from moderately dark sites and shows quite a bit of detail even through small telescopes.
Rogelio’s image is unusual. First of all, it shows a huge area of the sky; Andromeda is several times the apparent size of the full moon in the sky (see here for a comparison). Hold up your hand, and fold in your pinky and thumb; the width and length of your three middle fingers extended at arm’s length would be about the same area of sky as the photo.