But that isnt what you would see by eye or even a normal telescope. That is a long-exposure image. By eye you can only see the brighter/smaller core. Get a more sensitive camera, something able to see the diffuse gas and dimmer stars, and andromeda would be twice even that size.
I think the goal is to get a better sense of "how much of my visual space would this object occupy if I could see it". I had no idea Andromeda would appear larger than the moon from here if I could see it with my naked eyes. That really helps me get a sense of the size.
"Wow, it's that large even though it's that far away!?"
You're right! But I tried tonight just to see if it was possible to see anything at all. My eyes are kind of shitty but we live out in the boonies with no light pollution. There's a little 'yellow brick road' of stars that lead you to it and if i looked slightly aside i could juuuuuuuuust make out the slightest smudge where it is supposed to be. It was right on the edge of my ability to perceive it, need to try again after spending an hour in the dark.
