We all know that the distances are big in the universe, but do we really know HOW big they are? We mentioned something about the scales of the Universe few days ago when we discussed about the possibility of an asteroid slamming into our planet.
It is hard to get a picture of the scales when [...]
We all know that the distances are big in the universe, but do we really know HOW big they are? We mentioned something about the scales of the Universe few days ago when we discussed about the possibility of an asteroid slamming into our planet.
It is hard to get a picture of the scales when the distances are so big, but by decreasing the scale much smaller we can compare the distances to something we know well, the distances on Earth. This short article aims in giving a demonstration of the distances in the Universe.
We start by decreasing the scale into 1/10.000.000.000, which means all objects and distances between the objects are ten billion times smaller than the original ones. Now the Sun has diameter of 14 cm, a pretty much the size of a grapefruit. In this scale the Earth has a diameter of 1.2 mm, which is the size of a pin head. In this scale the Earth orbits the Sun 15 meters apart, while Saturn orbits 140 meters apart. The nearest star, Alpha Centauri, is located 4.3 light years away from us. In the decreased scale it would be located 4000 km apart from the Earth, which is the distance from Helsinki in Finland to Kabul in Afganistan.
When we decrease the scale this we can understand better how far the objects in space are located from each other. Imagine having a grapefruit here in the middle of Helsinki as well as a pin head orbiting that grapefruit 15 meters apart. Those are the Earth and the Sun. Now think that there is another grapefruit located in Kabul in Afganistan, 4000 kilometers apart from the grapefruit in Helsinki. Even though Alpha Centauri is our nearest star, it does not sound so “near” anymore.
Confused? Read more and get more confused. Imagine that the Earth, the Sun, the Solar System and Alpha Centauri are all part of the Milky Way galaxy which has about 500 billion stars. The mass of the Milky Way is about 750-1000 billion times the mass of the Sun. The galaxy has a diameter of 80.000-100.000 light years and it orbits its center in 226 million years (so called galactic year). Isn’t our home galaxy big? Yes, it is big, but it is a tiny little pin head in the whole Universe.
Our galaxy Milky Way belongs to a local group of galaxies, which again belongs to the supercluster of smaller galaxy groups. The supercluster we belong into is just one of the 10 million superclusters in the Universe.
When you think about the distances between the Earth, the Sun and our nearest star Alpha Centauri, and then think about the galaxies, groups of galaxies and superclusters, you start figuring out how huge the Universe is. Isn’t that amazing? Yes, it is awesome. It is one of the main reasons why I got interested in astronomy.
This article was written by Marko Pyhajarvi and its original location is in HomeboyAstronomy.Com astronomy blog. For more great astronomy articles, please visit HomeboyAstronomy.Com!
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