Andromeda Galaxy: how to find it, how far it is, and will it collide with the Milky Way?

The Andromeda Galaxy (M31) is the nearest large galaxy to our Milky Way, about 2.5 million light-years away, and you can see it with your own eyes. NASA says it is visible to the naked eye "even in areas with moderate light pollution", as a faint, oval smudge in the constellation Andromeda. It is best seen on autumn evenings in the Northern Hemisphere. The quick facts:

What is the Andromeda Galaxy?

A galaxy is a huge group of stars, gas and dust held together by gravity. Our Sun is one of the stars of the Milky Way. Andromeda is another spiral galaxy, and NASA calls it the nearest major galaxy to our own. It is also known as M31, number 31 in Charles Messier's catalogue.

It is enormous: according to NASA, the whole galaxy is about 260,000 light-years across. Its stars are too far away to see one by one with your eyes, so they blend into a soft glow. With the Hubble Space Telescope, NASA could pick out about 200 million stars hotter than our Sun, and that is still only part of the galaxy.

Andromeda is not alone. Smaller galaxies circle it, such as M32 and M110. NASA notes that M32 may be the leftover core of a galaxy that once collided with Andromeda.

How to find the Andromeda Galaxy

The easiest way is to hop from a bright star called Mirach (our calculations use SIMBAD star positions):

1. Find the Great Square of Pegasus, four stars in a big square, high in the sky on Northern Hemisphere autumn evenings (between east and south from New York in early November). One of its corner stars, Alpheratz, actually belongs to the constellation Andromeda. 2. From Alpheratz, follow the chain of bright stars leading away from the square. The first is delta Andromedae; the second, about 14.5 degrees from Alpheratz, is Mirach. 3. From Mirach, turn towards a fainter star, mu Andromedae, about 3.9 degrees away. In our New York view in the picture, that is upwards. 4. Continue roughly the same distance beyond mu Andromedae (about 3.9 degrees), almost along the same line. There you will find the Andromeda Galaxy: a faint, fuzzy oval, larger than a star.

Another guide is the W-shaped constellation Cassiopeia. Its bright star Schedar is about 15 degrees from the galaxy.

Look from a dark place, away from street lights, and give your eyes about 20 minutes to get used to the dark; NASA's Night Sky Network suggests a red light to keep your night vision. To your eyes alone, Andromeda is a faint, hazy patch. Binoculars show its bright core and a bit of the wispy disc around it. A telescope shows more detail but often cannot fit the whole galaxy in view, according to the Night Sky Network. You can check the positions for your own location with our Stellarium Web guide.

When is the best time to see Andromeda?

NASA names November as the best month to see Andromeda. From New York, at 9 p.m., it is at least 30 degrees above the horizon from about September 7 to February 7, and in mid-November it is almost straight overhead (our calculation). Times for the 15th of each month in New York, in local clock time (daylight saving time until 1 November):

When the highest point falls in daylight, you cannot see it then; look in the dark hours instead. A bright Moon lights up the sky, so the darkest evenings are around new Moon: November 9, 2026; December 8, 2026; January 7, 2027; February 6, 2027 (our calculation).

Andromeda never sets for anyone north of about 48.7 degrees latitude, for example in northern Europe and much of Canada, and it never rises for anyone south of about 48.7 degrees south (our calculation). From southern mid-latitudes, such as southern Australia or South Africa, it stays low in the northern sky; nearer the equator it climbs higher.

How far away is the Andromeda Galaxy?

About 2.5 million light-years, according to NASA. A light-year is the distance light travels in a year, nearly 10 trillion kilometres. A 2021 measurement listed in the SIMBAD database gives 761 ± 11 kiloparsecs, or 2.48 ± 0.04 million light-years (our conversion), which agrees with NASA's rounded figure.

That means the light you see from Andromeda tonight left it about 2.5 million years ago.

Could we ever travel there? Not with today's spacecraft. Voyager 1, the most distant spacecraft, moves away from the Sun at about 16.9 kilometres per second (see our Voyager 1 article). Covering today's distance to Andromeda at Voyager 1's current speed would take about 44 billion years (our calculation, ignoring how the galaxies move), more than three times the age of the universe, which is about 13.8 billion years (how old is the universe?).

Our animation places the measured positions on one flat map, so some gaps look shorter than they really are; the labels give the measured distances. It shows the Milky Way, its two companion galaxies the Large and Small Magellanic Clouds (about 0.16 and 0.20 million light-years away), Andromeda, and the Triangulum Galaxy (M33, about 2.74 million light-years away).

Will Andromeda collide with the Milky Way?

Maybe, but it is far less certain than people used to think. In 2012 NASA announced that, based on Hubble measurements, a collision was "predicted to happen four billion years from now", with the two galaxies merging "an additional two billion years after the encounter". NASA said Andromeda is "moving toward the Milky Way at about 250,000 miles per hour".

A 2025 study in the journal Nature Astronomy, led by Till Sawala, looked again with newer data from the Gaia and Hubble space telescopes and ran many possible futures. Smaller galaxies matter: including M33 makes a merger more likely, but the Large Magellanic Cloud's orbit "makes their merger less probable". The authors found "a probability of close to 50% that there will be no Milky Way–Andromeda merger during the next 10 billion years" and concluded that "the fate of our Galaxy is still completely open". Durham University, one of the research partners, says there is "only a 2% probability that the galaxies will collide in the next 5 billion years", and if they do merge, "it would most likely happen in 7 to 8 billion years' time".

Would Earth survive? Stars in galaxies are very far apart. NASA's 2012 release said the galaxy encounter puts Earth and the solar system in "no danger of being destroyed", although the Sun would likely "be flung into a new region of our galaxy". That is not a promise that Earth lasts forever: the Sun itself is a separate threat. NASA's 2025 article on the new study notes that the Sun will likely burn out in about 5 billion years, whatever the galaxies do.

Is Andromeda bigger than the Milky Way?

It looks that way in size. NASA describes Andromeda as a spiral galaxy like ours, but larger, spanning about 260,000 light-years. Which of the two galaxies is heavier is less clear: the mass of a galaxy is hard to measure, and the 2025 study lists the masses of the galaxies among the main uncertainties for the future.

How big does it look in our sky? Bigger than you might expect. A NASA image description says Andromeda spans nearly 3.8 degrees, close to the width of eight full Moons side by side.

Andromeda Galaxy FAQ

Can you see the Andromeda Galaxy with the naked eye? Yes. NASA says it is easy to see with the unaided eye from a dark site, and visible even with moderate light pollution. It looks like a faint, fuzzy oval.

Is there a real photo of the Andromeda Galaxy? Yes, many. The NASA images in this article were made from telescope observations in ultraviolet, infrared and X-ray light; their colours represent light our eyes cannot see, so the galaxy does not look like this to the eye. Our other visuals are charts, a Stellarium simulation and an animation built from measured positions and distances.

What is so special about the Andromeda Galaxy? It is the nearest large galaxy to the Milky Way, and you can see it without a telescope even though its light has travelled for about 2.5 million years.

How long would it take to reach Andromeda? Covering today's distance at Voyager 1's current speed would take about 44 billion years (our calculation, ignoring how the galaxies move). Even light needs about 2.5 million years.

What year will the Milky Way collide with Andromeda? Nobody knows. NASA's 2012 estimate was about 4 billion years; a 2025 study gives only a 2% chance of a collision in the next 5 billion years and close to a 50% chance of no merger within 10 billion years.

Will Earth survive a collision with Andromeda? In 2012 NASA said the encounter itself would put Earth and the solar system in no danger of being destroyed, because stars are so far apart. Earth's long-term future depends on the Sun instead: NASA notes it will likely burn out in about 5 billion years, whatever the galaxies do.

Have two galaxies ever collided? Yes. NASA points to NGC 520, a galaxy that is the product of a collision between two disc galaxies that started about 300 million years ago. Closer to home, Andromeda's companion M32 may be the leftover core of a galaxy that once collided with Andromeda, NASA says.

Can life exist in the Andromeda Galaxy? Nobody knows. It is a galaxy much like ours, with a huge number of stars, but so far there is no evidence of life there. See is there life on other planets?

Which constellation is Andromeda in? In the constellation Andromeda, next to Cassiopeia and the Great Square of Pegasus. Winter stargazers can also look for Orion.

How we checked

Distances and positions come from the SIMBAD database (CDS, Strasbourg), queried on 26 October 2026; we converted kiloparsecs to light-years (1 parsec ≈ 3.26156 light-years) and placed the galaxies on a map from their sky positions. Heights in the sky from New York and the star-hop angles are our calculations with the Astronomy Engine library; the sky view was simulated in Stellarium and checked against it. New Moon dates are from Astronomy Engine. Facts, photos, observing tips and the collision forecasts come from NASA, Durham University and the 2025 Nature Astronomy paper, listed under Sources. We checked all sources on 26 and 27 October 2026.

The collision chart shows the values each source quotes; we did not run our own simulation. None of the images or videos is AI-generated.