The Andromeda galaxy is 6 times bigger in the sky than the full Moon: it's just too dim to clearly see it with the naked eye.
This composite image shows what it would look like at night if it was just brighter.
[📸 Tom Buckley-Houston] 
Discussion
Here’s a couple shots I took the other night. You can see a slight oval haze around the galactic center. 
That’s nice
I remember being blown away when I first learned how to spot this reliably on a clear night with the naked eye, realizing that instead of looking at a star, I was looking at over 300 billion stars in a patch of sky the size of my pinky fingernail on an outstretched arm. And that I was seeing it not as it is now, but as it looked 2.5 million years ago when the light I was seeing left it
⭐️