NASA news: Beautiful Hubble snap reveals a colossal galaxy heading to the Milky Way

Andromeda can be seen in exquisite detail in the NASA photograph. This is because the image is actually the result of a total of 7,398 exposures taken over 411 individual pointings made by the Hubble Space Telescope. The 1.5 billion pixels in the mosaic reveal over 100 million stars and thousands of star clusters embedded in a section of the Andromeda galaxy. Despite the fact Andromeda is more than two million light-years away, constant upgrades to Hubble allow the telescope enough power to resolve individual stars in this 61,000-light-year-long stretch of the disk. NASA added: “It’s like photographing a beach and resolving individual grains of sand.” The image shows Hubble tracing densely-packed stars extending from the innermost hub of the galaxy, to the left of the photo. Moving out from this central galactic bulge, the panorama sweeps across lanes of stars and dust to the sparser outer disk. Cooler, yellowish stars dominate the galaxy’s core, toward the lower left. The blue, ring-like feature wrapping from the upper left to the lower right is a spiral arm with numerous clusters of young, blue stars and star-forming regions. DON'T MISS TESS satellite presents stunning new southern sky mosaic [VIDEO] Life discovered deep underground points to ‘subterranean Galapagos' [INTERVIEW] Shadow land: ‘Alien life can exist in 2D universe' [INTERVIEW] And the dark silhouettes trace out complex cosmic dust structures. M31 is located in the constellation Andromeda and is best observed in November. Boasting an apparent magnitude of 3.1, the galaxy can be seen with the naked eye, even in areas with moderate light pollution. Because the star cluster is such an easily observed feature in the night sky, no-one knows who discovered the Andromeda galaxy. However, Persian astronomer Abd al-rahman al-Sufi’s The Book of Fixed Stars from the year 964 contains the first known report of the object. The emergence of the cosmic mosaic coincides with the news two ancient migration events took place in the Andromeda galaxy. Astronomers have uncovered two historic events in which the Andromeda Galaxy underwent major changes to its structure. The findings shed light not only on the evolution and formation of the Andromeda Galaxy, but also to our own Milky Way. Large galaxies such as ours are believed to grow through repeated merging with smaller, dwarf galaxies.