There was a time when we used to believe that the Earth was at the center of the universe and everything revolved around it. As the mankind grew wiser, we came to realize that it was, in fact, the Earth that revolved around the sun and was never the center of the universe. The human kind has just started to understand the mysteries of the universe and one may say that what we know is merely a drop in the bucket.
Some might even say that we are still exploring our own solar system since several mysteries need unraveling. How much do you know about our solar system? Which planet has the most moons? Is Pluto a planet? What we are planning to talk about today is the distance between the Earth and the sun. Do you know the answer? No? No worries! Just buckle up as we take you on a journey through our solar system!
(Image Courtesy: Wikipedia)
Distance Between Earth And Sun
The distance between the Earth and sun is said to be 149,597,870,700 meters or 92,955,807 miles. This distance is called an astronomical unit or AU, which is used to calculate the distance in the entire solar system. For instance, Jupiter, the fifth planet of our solar system, is 5.2 astronomical units from the sun, whereas Neptune, the eighth planet of our solar system, is approximately 30.07 AU from the sun. The Oort Cloud on the outer edges of the solar system which is said to be the origin of comets is approximately 100,000 from the sun, whereas the nearest star to it, Proxima Centauri is about 250,000 AU away.
(Image Courtesy: Science ABC)
An important point to note here is that the Earth does not revolve in a circular orbit around the sun. The shape that the Earth makes while revolving around the sun can best be described as an oval. Therefore, the distance between the Earth and the sun given above is the average distance between the two. The closest the Earth comes to the sun, which is referred to as perihelion occurs in January when the Earth and the sun are nearly 91 million miles or 147 million kilometers apart. Also, the oval revolution can also take the Earth and the sun as far as 94.5 miles or 152 million miles. This event is referred to as aphelion and occurs during July.
(Image Courtesy: Socratic)
Finding the Distance
You might be surprised to learn that the first person to have calculated the distance from the Earth to the sun was Aristarchus, who did it around 250 BC. More recently, the astronomer Christiaan Huygens did the same in 1653, using the phrases of Venus to determine the angles of the Earth-Venus-Sun triangle. For instance, a half lit Venus means the three bodies are making an equilateral triangle. Therefore, by rightly predicting the size of Venus, Huygens was able to measure the distance between Earth and Mars and then between the Earth and the sun.
Giovanni Cassini, in 1672, used another method, which involved parallax to find the distance between the Earth and Mars and the Earth and the sun. He and his colleague measured the position of Mars in relation to the background stars from Paris and French Guiana and then used the distance between the two areas to triangulate the measurements. The same method was used to find the distance with the sun.
(Image Courtesy: Transit of Venus 2012)
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(Featured Image Courtesy: EarthSky)