How fast are we travelling

For a simple example of parallax, hold up your index finger in front of your face at arm's length. Look at it with your left eye only, closing your right eye. Then close your right eye, and look at the finger with your left. The finger's apparent position changes. That's because your left and right eyes are looking at the finger with slightly different angles. The same thing happens on Earth when we look at stars.

It takes about days for us to orbit the sun. If we look at a star located relatively close to us in the summer and look at it again in the winter, its apparent position in the sky changes because we are at different points in our orbit.

We see the star from different vantage points. With a bit of simple calculation, using parallax we can also figure out the distance to that star.

Earth's spin is constant, but the speed depends on what latitude you are located at. Here's an example. The circumference distance around the largest part of the Earth is roughly 24, miles 40, kilometers , according to NASA. This area is also called the equator. If you estimate that a day is 24 hours long, you divide the circumference by the length of the day. Related: Check out some stunning images of Earth from space. You won't be moving quite as fast at other latitudes, however.

If we move halfway up the globe to 45 degrees in latitude either north or south , you calculate the speed by using the cosine a trigonometric function of the latitude. A good scientific calculator should have a cosine function available if you don't know how to calculate it. The cosine of 45 is 0. That speed decreases more as you go farther north or south. By the time you get to the North or South poles, your spin is very slow indeed — it takes an entire day to spin in place.

Space agencies love to take advantage of Earth's spin. If they're sending humans to the International Space Station, for example, the preferred location to do so is close to the equator. That's why cargo missions to the International Space Station, for example, launch from Florida.

By doing so and launching in the same direction as Earth's spin, rockets get a speed boost to help them fly into space. Earth's spin, of course, is not the only motion we have in space. We can calculate that with basic geometry. First, we have to figure out how far Earth travels. App Store Preview. Oct 3, Version 1. Ratings and Reviews. App Privacy. Information Seller Marcel Kraus.

Size 9. Category Navigation. Compatibility iPhone Requires iOS Languages English, German. The Sun, Earth, and the entire solar system also are in motion, orbiting the center of the Milky Way at a blazing miles a second.

Even at this great speed, though, our planetary neighborhood still takes about million years to make one complete orbit -- a testament to the vast size of our home galaxy.

Dizzy yet? Well hold on. The Milky Way itself is moving through the vastness of intergalactic space.