Our Solar System

Where are we? This is a question you have probably asked before, but a question that usually refers to a specific address or a location within a city or town. For some people, though, this question refers to where we are on Earth, or even, where we are in the Universe.

When considering time and size, humans are actually quite insignificant. We have only existed for about 5 million years. In comparison, cockroaches have lived for at least 300 million years. In terms of size, think about where you live and work. How far do you travel each day? Now, realize that the Earth’s diameter (the distance from one side to another) is about 7,900 miles, and its circumference (the distance all around the equator) is over 24,900 miles! To us, the Earth is extremely large. In fact, we still have not even explored it entirely. Nevertheless, even Earth is insignificant when compared to the Universe. The Universe is so gigantic that its size is still unknown.

The Earth belongs to a solar system containing eight planets, dwarf planets, and the Sun, and the Earth is considered one of the smaller planets in our solar system. Jupiter, for example, is so much larger than Earth that all of the other planets could fit inside of Jupiter. Our solar system is located on one of the outer arms, called the Orion arm, of the Milky Way Galaxy. There are approximately 200 billion stars within our galaxy. In the Universe, there are thought to be several billion galaxies. And by some estimates a trillion galaxies. 

Why have we not explored the entire Universe, yet? Well, if you were to travel at the speed of light, which is 186,000 miles per second, it would take you 100,000 years to cross our Milky Way. Just to get to the nearest galaxy would take you another 2 million years!

Earth’s neighborhood, the solar system, consists of eight planets, some dwarf planets, several moons, thousands of asteroids, a few comets, and the Sun. They all move due to the gravitational pull of big bodies, in other words anything in outer space that has weight. And, of course, the larger the body, the stronger the pull it will exert. Thus, the moons circle the planets, and planets circle the Sun.