This story is part of our “Cosmic Perspective” series, which confronts the incredible vastness of the universe and our place in it. Read the rest of the series here.
This map shows the cosmic ring that surrounds us, stretching out to distances of up to 200 million light-years. At this scale, the universe is made up of galaxy clusters and voids, the latter being regions with relatively few galaxies. The Milky Way at the center is part of the Local Group, while the Virgo Cluster is our nearest neighbour.
The magnificent spiral
The Milky Way’s spiral structure is dominated by two major arms called Scutum-Centaurus and Perseus. It also features a dense region called the central bar. Our solar system sits on a more modest structure called the Orion Arm.
No matter how complex the questions about our metaphorical place in the universe, astronomy can help us understand Earth’s physical location.
Earth orbits at a distance of 150 million kilometers from the Sun, which in turn orbits the center of the Milky Way galaxy. Specifically, Earth is located in the Orion Arm, about 26,500 light years from the center.
The Milky Way Galaxy is part of the Local Group of galaxies. Its nearest neighbor, the Andromeda Galaxy, is about 2.5 million light-years away and is the largest galaxy in the Local Group. We are currently hurtling towards the Andromeda Galaxy at over 100 kilometers per second, and in about 4 billion years the two galaxies will collide.
Local Groups
It will shake up local groups, but it will barely be on the radar of the wider cosmic neighborhood.
Source: www.newscientist.com
