This is the point around which the Earth spins. The Earth spins around on its axis once in one day. This is why we see the Sun rise in the east, because the Earth turns in that direction, and so do you. Because the Sun seems to move across the sky, you may be forgiven for thinking the Sun travels around the Earth. Curious Kids is a series by The Conversation that gives children the chance to have their questions about the world answered by experts.
This movement of the Earth also means that on a clear night you will see the stars rise in the east and set in the west, like the rising and setting of the Sun in the day. In the North, this happens to be very close to a star called Polaris, or the North Star. The earth is moving with respect to the CBR at a speed of kilometers per second. We can also specify the direction relative to the CBR. It is more fun, though, to look up into the night sky and find the constellation known as Leo the Lion.
The earth is moving toward Leo at the dizzying speed of kilometers per second. It is fortunate that we won't hit anything out there during any of our lifetimes! Already a subscriber? Sign in. Thanks for reading Scientific American. Create your free account or Sign in to continue. 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. Tigger Bestie 14 Jan. The editors spelled the word, 'Earth' wrong! See if you can spot it! AnnaCT 15 Jan. AnnaCT replied: Oh yeah!
You are very good at noticing small details! Summer 14 Jan. CamoflaugeWolf13 13 Jan. Good or bad? Let me know what you think by commenting! Chloe 13 Jan. Candy 13 Jan. BlueSparklyGymnast 13 Jan. Cool or what?! Lunarella45 13 Jan. CamoflaugeWolf13 replied: Hehe. More replies 2 down.
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