The Andromeda Galaxy
also known as M31, a spiral galaxy located approximately 2.5 million light-years away from Earth, is the closest galaxy to our Milky Way and can be visible to the naked eye when the observer is in a very dark location. With a diameter of over 220,000 light-years, it is one the largest galaxies in the Local Group.
This image combines over 20 hours of exposures, made from 559 individual sub-exposures. These were captured over 8 nights between October and December 2022 from a back garden in Prestwick,
Scotland with a dedicated astrophotography setup.
Did you know?
The Andromeda Galaxy contains an estimated one trillion stars—several times more than our own Milky Way. Even from such an incredible distance, the combined light of those stars is bright enough for us to see its glowing core with the naked eye under a dark sky. Yet that’s only a small part of the galaxy. Its full extent actually stretches across the sky by about six times the width of the full Moon, but most of it is simply too faint for our eyes to detect.
Voyager 1, the most distant human-made object ever launched, has been travelling through space since 1977 at around 17 kilometres per second (about 61,000 km/h). Despite nearly 50 years of continuous travel, it has covered less than one-billionth of the distance to Andromeda. At its current speed, the journey would take around 75 billion years. Meanwhile, Andromeda itself is racing towards the Milky Way at around 110 kilometres per second—over six times faster than Voyager 1—yet the two galaxies won’t begin to merge for another 4–5 billion years.
Every photon captured in this image spent around 2.5 million years crossing the vast emptiness between galaxies without being absorbed, scattered or striking anything. It then passed through the Milky Way, Earth’s atmosphere, my telescope and camera, before ending its extraordinary journey on a single pixel of my camera sensor in Prestwick.