The Andromeda Galaxy or Andromeda Nebula is the nearest major galaxy to the Milky Way, as well as one of the few galaxies to be observed from Earth.
1. Because Andromeda is the closest spiral galaxy to us, it is used by astronomers to understand and study the origin and evolution of these types of galaxies.
2. Scientists estimate that in about four billion years, Andromeda and the Milky Way galaxy will collide to a new giant elliptical galaxy.
3. The Andromeda Nebula is constantly approaching our galaxy with a radial velocity of 120-140 kilometers per second.
4. At the Galactic Core of Andromeda, in addition to a massive globular cluster, there is at least one supermassive black hole.
5. There are 14 dwarf galaxies and more than 400 globular clusters move around Andromeda Galaxy.
6. Andromeda Galaxy swallowed many dwarf galaxies during its lifetime. As dwarf galaxies are pulled in by gravity, they have also pulled apart, leaving behind long trailing streams of stars and compact star clusters.
7. Andromeda is home to over 1 trillion stars. That’s over at least two times more stars than the Milky Way.
8. The distance from Earth to the Andromeda galaxy is 2.52 million light-years or 778 kiloparsecs.
9. According to current estimates, the mass of Andromeda is roughly 800 billion solar masses, the mass of the Milky Way, on the other hand, is 1.5 trillion solar masses.
10. The Andromeda Nebula is one of the most distant objects you can see with the naked eye from Earth.
11. The Andromeda Galaxy is also known as Messier 31, M31, or NGC 224 and was originally the Andromeda Nebula.
12. What’s interesting about Andromeda is that the first known report of our nearest neighbor was written in 964, the Persian astronomer Abd al-Rahman al-Sufi described the galaxy as a “small cloud” in his “Book of Fixed Stars”.
13. The first photographs of the Andromeda Galaxy were taken on 29 December 1888 by Isaac Roberts using a 20-inch aperture reflecting telescope, he displayed these photographs at the Royal Astronomical Society at Liverpool, of which he was president, but it was still commonly thought to be a nebula within our galaxy.
14. The most famous globular cluster belonging to M31, the Andromeda galaxy, Globular One (officially named Mayall II), is the largest of any in our Local Group of galaxies.
15. In 2015, scientists released the most detailed photo of Andromeda ever using a mosaic of images from the largest NASA Hubble Space Telescope, which included 7,398 exposures taken over 411 pointings of the telescope.
