When will Andromeda galaxy look as big as the moon today?

In summary, M31 is a very large galaxy and it is already as big as the moon in the night sky. You will need good dark skies to see it.
  • #1
waht
1,501
4
Since our galaxy and the andromeda galaxy are drifting towards each other. How long will it take to look as big as the moon today in the night sky?
 
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  • #2
It already does.
It's just very faint, so it's hard to see under normal conditions.
But the Andromeda galaxy is as big, if not bigger, than the apparent diameter of the Moon in the sky (about half a degree of arc.)
 
  • #4
Thanks, didn't know that. I always thought it was just a small fuzzy ball in the night sky.
 
  • #5
Get some good binoculars and a dark sky...

I'm on an astrophotography site and many novices complain that when they point their telescope at M31 and shoot some pictures, all they see is a bright blob - they don't realize that that's because they have so much magnification they can only see the core.
 
  • #6
With the naked eye, how big should M31 appear? I have tried and tried and have never been able to spot it. (I do know exactly where to look, and have even tried using my peripheral vision). I have often suspected that I don't know what I should be looking for size-wise. I presume it is brightest at its centre, thus its apparent size will be smaller because I'd only be seeing the bright core.
 
  • #7
Yep - the thing is HUGE...

With a telescope - unless you have A LOT of aperture - all you are going to see is the core.

With binocs and a good sky, it's whole other story
Starry Night puts it at a little over 2 degrees across - but I was at a Star-Camp event last week, in Kielder Forest - generally regarded as England's darkest spot - and I could see the faint haze of the disk, extending as wide, possibly even WIDER than the FoV of my SkyMaster 15x70 binocs (4 degrees FoV)

Naked eye - it appeared as wide as the gap between 'nu' and '32'Andromeda, immediately below it.

BTW - If anyone is interested, I did a bit of a write-up of my own experience of the Kielder event for my own little forum community...
http://astro.forumup.co.uk/viewtopic.php?t=113&mforum=astro
 
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  • #8
M31 is listed at 4th magnitude, so you'll need pretty dark skies to pick it up at all with the naked eye and when you do, it'll be barely more than a fuzzy star. If you look at the photo in the link, you can see just how much brighter the core is than the outer areas - and that's probably with unequal stretching of the brightness (in my pictures, I can't get it that balanced). So the outer starfields are nowhere near bright enough to see naked eye.

If I can find it when I get home, I have a photo taken with a standard digital camera at no magnification that shows it...

Actually, for now, take a look at my photos of it on my website (shameless plug) - check out how washed-out the core is in the first one. Try looking at the thumbnail from 20 feet away... http://www.russsscope.net/deepspace.htm
 
  • #9
Nice shots Russ!
 

Related to When will Andromeda galaxy look as big as the moon today?

1. When will Andromeda galaxy be visible as big as the moon?

The Andromeda galaxy is approximately 2.5 million light-years away from Earth, making it impossible for it to ever appear as big as the moon in our night sky. Its apparent size will always be much smaller than the moon, even with the use of powerful telescopes.

2. Is there a specific time or date when the Andromeda galaxy will look as big as the moon?

No, there is no specific time or date when the Andromeda galaxy will appear as big as the moon. Its size and distance from Earth remain constant, so it will always appear smaller than the moon in our night sky.

3. Can I see the Andromeda galaxy with the naked eye?

Yes, the Andromeda galaxy is visible to the naked eye under dark and clear skies. However, it will appear as a small, faint smudge of light and will not be as large as the moon.

4. Will the Andromeda galaxy ever collide with the Milky Way galaxy?

Yes, according to current scientific understanding, the Andromeda galaxy and the Milky Way galaxy are on a collision course and will eventually merge into one galaxy. However, this will not happen for another 4.5 billion years.

5. Can I see the Andromeda galaxy during the daytime?

No, the Andromeda galaxy is only visible in the night sky. Its faint light is easily drowned out by the sun's brightness during the day.

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