How Big Is Earth in the Universe?


Farrah Israel, Staff Writer

How big is the universe, and how big is earth in comparison to it? These are two of the greatest and most mysterious questions ever asked. Most of us know the basics––Earth is located in the Solar System, which contains eight planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. The Solar System also contains stars, asteroids, comets, and dwarf planets like Pluto. It is called the Solar System because the Latin root for the word sun is “sol,” giving the prefix of the word “solar.” 

The Solar System is located within a galaxy called the Milky Way. Galaxies take on many shapes: spiral, elliptical, and irregular. The Milky Way has a spiral shape. There are four arms in the Milky Way; the Solar System is located in one of the outer arms called the Orion Arm. The Solar System orbits around the Milky Way at a speed of 515,000 mph.

Every galaxy belongs to a cluster of galaxies that contain anywhere from hundreds to tens of thousands of galaxies. The Milky Way belongs to a cluster of galaxies known as the Local Group, which is around the outside of the Virgo Cluster. There are also superclusters which include three to ten clusters. The Local Group is part of the Virgo Supercluster, which includes many clusters. 

Every galaxy is located within the universe. It is estimated that the Milky Way is only one of two trillion galaxies in the universe. To put the size into perspective, if our universe was the size of the Empire State Building, the Milky Way would be a small crumb in the building. That makes the earth only a fraction of that crumb. 

To put the relativity in simpler terms, a planet is basically like your house. A planetary system is like your street. A galaxy is like your neighborhood. A galaxy cluster is like your town. A supercluster is like your county. The Universe is like your state. 

Overall, the Earth is very small in comparison to the entire universe, yet sometimes we believe that Earth contains the only existing forms of life. Considering how large the universe is, who knows if that is true? Maybe there is life beyond Earth?