The Andromeda galaxy is a spiral galaxy approximately 2.5 million light-years (2.4×1019 km) from Earth. It contains some trillion stars, which is about 3 times more than our Milky Way galaxy.
Although it appears more than six times as wide as the full Moon when photographed through a larger telescope, only the brighter central region is visible to the naked eye or when viewed using binoculars or a small telescope.
Here is what this galaxy looks like through a large telescope:
All the regular stars we see are within our local Milky Way galaxy. Most of these visible stars are several hundred or several thousand light years away.
Now consider going outside to see the Andromeda galaxy in person, per directions below. First, prepare yourself that what you will actually be able to see is a small, faint glowing patch, like a tiny cloud of white mist.
Even though that appears unspectacular, I still am impressed every time I see the Andromeda galaxy that the light entering my eyes started on its way 2.5 million years ago. The first of the four major Pleistocene ice ages was starting about then. The main human ancestor that we know from that time was Homo habilus. His brain was about half the size of ours, and he was just figuring out how to chip stones into sharp tools.
Viewing the Andromeda galaxy
Here is a star chart, with two ways to hop to Andromeda galaxy from nearby constellations. The first method, using the constellation Cassiopeia (see yellow “(1)” and yellow arrows) is probably the easiest. Cassiopeia is shaped like a “W”, and is nearly overhead around 8:00 in Nov-Dec. The four corners of the big square of Pegasus (the stars Alpheratz, Scheat, Markab, and Algenib on the star map) are visible to the naked eye, as is Mirach and Almach. But I cannot see the other little stars labeled “…And” on this map.
The Andromeda galaxy itself is almost directly overhead in the early evening each year in November-December. Some people are able to spot it with their unaided eyes, though I cannot. It should work fine with binoculars, if you patiently scan around the correct area, and only expect to see a tiny fuzzy patch, not a giant spiral. You need a fairly clear night, without a bright moon, and away from bright lights. A suburban back yard can work. Now is a good time to try this, since the moon is in its dark phase for the next week.
You might want to lie down on your back or in a recliner for looking straight up. Younger children may not be able to handle and use binoculars well enough. Using a telescope takes more set-up than binoculars, but then the galaxy is locked in view. Low magnification power works better. I have introduced a number of neighborhood children to Andromeda this way, after showing them the glorious spiral image above, so they know what that fuzzy thing in the telescope really is.
Bonus viewing this month: Venus is visible, looking like a brilliant white star, after sunset near where the sun went down.