UCSB Science Line
 How is the earth floating in space? Question Date: 2018-03-13 Answer 1: The earth is not actually floating in space, but it is moving around the sun. We can think of the earth like a car moving in a circle. If the earth is constantly turning left, it will eventually move in a circle. However, instead of the earth turning with a steering wheel, it is turning due to the sun, which pulls the earth in towards it. Since the sun is so big, the earth experiences this force, called gravity, which makes the earth want to come towards the sun. The earth wants to go in a straight line, but the sun is at the left, and makes it want to go toward it, so the earth turns a little bit to the left. The sun then pulls the earth a little bit more to the left, and eventually, the earth just goes around in a circle. This force is similar to what we feel on Earth. Since the earth is so much bigger than we are, the earth pulls us toward its center. This is why we always feel a force down into the ground. The same thing happens to the moon, where the earth pulls the moon toward it, since the earth is so much bigger than the moon. The moon also pulls on the earth, but it is not as big so we do not notice it as much. When the moon pulls on the earth, we actually feel it in the ocean, and it causes the ocean waves to come up and down. The ocean is easier to move than the entire earth, so we notice it more. I hope this helps you understand gravity, and why the earth and some planets move around the sun! Answer 2:Technically speaking, the earth is not "floating". The act of floating (as a boat or person would in water) requires the simultaneous existence of the force of gravity (down toward the earth's surface) and the force of buoyancy (upward away from the earth's surface, provided by a fluid such as water or air). The earth itself is not in a body of water, and the density of gases is so low in space that there is no significant buoyant force pushing it "up". Additionally, the concept of "up" and "down" do not really exist in space. The earth is being pulled toward anything because it is balanced by the gravitational force of the sun and its own rotational motion. The rotational motion of the earth keeps it from flying into the sun, so the earth is not moving "toward" or "away" from anything in particular. Answer 3: The earth is actually falling, not floating. It's just that the earth is moving fast enough in the forward direction that it can't actually fall into the sun, which it would fall into otherwise. This is what we mean by the earth being "in orbit" - it is continually falling, but never hits what it's falling around. Click Here to return to the search form.