Why does earth revolve around the sun

Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Learn more. Why does the earth revolve around the sun? Asked 3 years, 11 months ago. Active 3 years, 11 months ago. Viewed 2k times. Improve this question. Sarah M Sarah M 3 3 3 bronze badges. Add a comment. Active Oldest Votes. First, please note that "rotate" actually is used to describe an celestial body's spin, and "revolve" is used to describe its orbital motion.

For example, the Earth completes one rotation about its axis about every 24 hours, but it completes one revolution around the Sun about every days. Anyway, the basic reason why the planets revolve around, or orbit , the Sun, is that the gravity of the Sun keeps them in their orbits.

Just as the Moon orbits the Earth because of the pull of Earth's gravity, the Earth orbits the Sun because of the pull of the Sun's gravity. Why, then, does it travel in an elliptical orbit around the Sun, rather than just getting pulled in all the way? This happens because the Earth has a velocity in the direction perpendicular to the force of the Sun's pull. If the Sun weren't there, the Earth would travel in a straight line. But the gravity of the Sun alters its course, causing it to travel around the Sun, in a shape very near to a circle.

This is a little hard to visualize, so let me give you an example of how to visualize an object in orbit around the Earth, and it's analogous to what happens with the Earth and the Sun. Imagine Superman is standing on Mt. Everest holding a football.

He throws it as hard as he can, which is incredibly hard because he's Superman. Just like if you threw a football, eventually it will fall back down and hit the ground. But because he threw it so hard, it goes past the horizon before it can fall. And because the Earth is curved, it just keeps on going, constantly "falling," but not hitting the ground because the ground curves away before it can.

Eventually the football will come around and smack Superman in the back of the head, which of course won't hurt him at all because he's Superman. That is how orbits work, but objects like spaceships and moons are much farther from the Earth than the football that Superman threw. We're ignoring air resistance with the football example; actual spacecraft must be well above most of a planet's atmosphere, or air resistance will cause them to spiral downward and eventually crash into the planet's surface.

This same situation can be applied to the Earth orbiting the Sun - except now Superman is standing on the Sun which he can do because he's Superman and he throws the Earth.

First, let's recall what causes the phases of the moon— here is a refresher. In short, half of the moon is illuminated by the sun. Since we look at the moon from different angles, we only see part of the illuminated half of the moon and this causes the phases. The exact same thing is true for Venus. So, if Venus has a crescent-shaped phases, that means that we are looking at the "back side" of Venus.

If Venus has a full phase, we are looking at the "front side. But wait! That doesn't mean the solar system has to be heliocentric. It's still possible that the Earth is at the center and the sun orbits the Earth but Venus orbits the sun. It would be weird—but it's possible. Here is another thing you can see with a pair of binoculars.

Take a look at Jupiter when it's visible in the sky. If you haven't ever tried this—you need to do this. Trust me. It's pretty awesome. You won't really be able to make out details about the planet Jupiter, but you can see the four big moons. Yes, you can see the moons of Jupiter with binoculars.

But what do these Jupiter moons say about the model of the solar system? Just like the phases of Venus, this doesn't prove that the geocentric model is wrong. However, it is obvious that these moons are orbiting Jupiter and not the Earth. So, Earth isn't the center of everything. This one is classic—and you don't even need a telescope or anything.

You only need some patience. Here's what you do. Go outside at night and notice the location of Mars with respect to the background stars. Do this again the next night and you will notice that it is in a different location with respect to the background stars. The solar system is basically a massive game of tug of war, and all of the yanking balances out at a specific point: the center of mass, or " barycenter.

Sometimes, it's almost smack dab at the Sun's center. Right now, the barycenter is just outside the Sun's surface. But it's constantly changing depending upon where the planets are in their orbital paths.