Andromeda is part of the Local Group of galaxies. The Andromeda Galaxy is the closest full-size galaxy to the Milky Way. The Andromeda Galaxy is about four times larger than the Moon in the sky. Andromeda contains about a trillion stars. The Andromeda Galaxy is also the only galaxy visible to the naked eye in the Northern Hemisphere. The Andromeda Galaxy is the largest galactic galaxy in the Milky Way and is on track for a collision in the future. It is believed that the Milky Way and the Andromeda Galaxy, also known as M31, will collide in the future. The Andromeda Galaxy continues to move toward the Milky Way at about 250,000 miles per hour. The Milky Way and Andromeda move towards each other under the pull of gravity. Initially, the two galaxies may spin past or through each other, dragging out long gravitational tails. Then the Milky Way will be distorted and unrecognizable. But then the gravitational attraction of the dark matter halos of the galaxies will cause them to coalescence. When everything settles down in about a billion years, the combined ex-spirals may have created a large, egg-shaped galaxy glowing with newborn suns. These new star systems will be rich in heavy elements and will nurture Earth-like plants. Furthermore, the Triangle could be part of the collision. This collision will take place in about four billion years. There is also a slim chance that M33 will arrive at the Milky Way first and collide as well. It will take another two billion years after the collision for both to merge into a single galaxy. (space.com 1)The first route to Andromeda starts from the constellation Cassiopeia. It is always above the horizon in mid-northern latitudes, opposite the North Star, Polaris, from the Big D... in the center of the chart... curious spots known as nebulae that were found within them. Heber Curtis detected multiple stars in Andromeda and argued that it was a separate galaxy. His argument was not concluded until 1925, when Edwin Hubble identified a special type of star known as a Cepheid variable. A Cepheid variable is a star whose characteristics allow exact distance measurements within Andromeda. Since Shapley had previously determined that the Milky Way was only 100,000 light-years in diameter, Edwin Hubble's calculations reported that the blurred zones were too far away to be within the Milky Way. (www.crystalinks.com 1) In conclusion, the Andromeda Galaxy is a very important galaxy because it influences other galaxies, such as the Milky Way. The Andromeda Galaxy is getting closer and closer to the Milky Way every second and will collide into a single galaxy in the future.