Perhaps that seems a bit sluggish -- after all, Mars Pathfinder journeyed to Mars at nearly 75, miles per hour. Buckle your seat belts, friends. 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. However, experts predict that this speeding up is a temporary effect and the Earth will start slowing down again in the future.
But, for now, should we be worried? Although it will have no effect on our daily lives, there could be serious implications for technology such as GPS satellites, smartphones, computers and communication networks, all of which rely on extremely accurate timing systems. This latter motion is called centripetal acceleration.
At its strongest point, which is at the equator, centripetal acceleration only counteracts Earth's gravity by about 0. In other words, you don't even notice it, although you will weigh slightly less at the equator than at the poles. NASA says the probability for Earth stopping its spin is " practically zero " for the next few billion years. Theoretically, however, if the Earth did stop moving suddenly, there would be an awful effect. The atmosphere would still be moving at the original speed of the Earth's rotation.
This means that everything would be swept off of land, including people, buildings and even trees, topsoil and rocks, NASA added. What if the process was more gradual? This is the more likely scenario over billions of years, NASA said, because the sun and the moon are tugging on Earth's spin. That would give plenty of time for humans, animals and plants to get used to the change.
By the laws of physics, the slowest the Earth could slow its spin would be 1 rotation every days. That situation is called "sun synchronous" and would force one side of our planet to always face the sun, and the other side to permanently face away.
By comparison: Earth's moon is already in an Earth-synchronous rotation where one side of the moon always faces us, and the other side opposite to us. But back to the no-spin scenario for a second: There would be some other weird effects if the Earth stopped spinning completely, NASA said. For one, the magnetic field would presumably disappear because it is thought to be generated in part by a spin.
We'd lose our colorful auroras, and the Van Allen radiation belts surrounding Earth would probably disappear, too. Then Earth would be naked against the fury of the sun. Every time it sent a coronal mass ejection charged particles toward Earth, it would hit the surface and bathe everything in radiation.
Join our Space Forums to keep talking space on the latest missions, night sky and more! And if you have a news tip, correction or comment, let us know at: community space. Elizabeth Howell is a contributing writer for Space. Travelling at the same speed means we cannot feel the spin. It is like driving a car. Only when you change speeds do you notice you are travelling, like putting your foot on the accelerator or making an emergency stop.
A change in speed has been happening here on Earth, but it is far too slow to notice.
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