When you add that up over an 80-year life span, it gives you a total movement of 930 billion miles (1.5 trillion km).Shahdad Desert, 30km east of Dasht-e Lut. By measuring this shift, astronomers can calculate our total velocity through the universe, and those measurements give a number of around 390 miles per second (630 km per second). Light in the direction we're headed in will get Doppler-shifted to higher frequencies (blueshift), and light in the direction we're moving away from will be shifted to lower frequencies ( redshift). It completely soaks the universe and is the same to one part in a million across the entire sky.Īny motion in the universe will be visible in the CMB. Beyond that, the Virgo cluster and its surrounding galaxies are all headed toward the Great Attractor, which is the center of our supercluster, called Laniakea.Īstronomers can calculate the combined motion of these gravitational influences by observing the cosmic microwave background (CMB), which is composed of radiation released when our universe cooled from a plasma state when it was only 380,000 years old. On top of that, both the Milky Way and Andromeda are headed toward the Virgo cluster, a massive cluster of galaxies about 65 million light-years away. The mutual gravitational attraction is enough to overwhelm the general expansion of the universe, and in about five billion years, these galaxies will begin to merge. On top of that expansion, each galaxy has some motion of its own - something astronomers dub "peculiar velocity." For example, the Milky Way is on a collision course with our nearest neighbor, the Andromeda galaxy. All galaxies are, on average, flying away from each other, but that's due to the expansion of the universe. Why is Earth's day 24 hours long (and how did the sun keep it from being longer)?Īnd it doesn't stop there. What would happen if Earth suddenly stopped spinning? Related: Stunning photos of our Milky Way galaxy But on a human scale, it's almost incomprehensible due to the motion of the sun orbiting the center of the Milky Way, each of us will travel around 370 million miles (600 billion km) in our lifetime. To put that into perspective, life first arose on Earth around 17 galactic years ago, and in only 25 more galactic years, the sun will die.Ĭompared with these enormous galactic scales, a human lifetime is barely perceptible, with the sun barely inching along its orbit. One of these "galactic years" takes roughly 230 million Earth years to complete. The sun travels in a long, lazy orbit around the center of the Milky Way galaxy. So over a lifetime, each of us travels roughly 50 billion miles (80 billion km) - which, again, dwarfs the distance we travel due solely to the rotation of our planet.īut Earth is not the only object in motion in the universe. That's about 600 million miles (1 billion km) every year. But on average, Earth's orbital speed is about 19 miles per second (30 km per second). That orbit is an ellipse, which causes our planet to occasionally move more quickly or slowly depending on its distance from the sun. In addition to rotating, Earth orbits the sun. That's a tremendous leap above the travel we do on Earth's surface, but we're just getting warmed up. (As we will see, precision doesn't really matter here.) When you add that up over a roughly 80-year life span, each person travels around 600 million miles (1 billion kilometers) in their lifetime. Most people don't live on the equator, however, so we can say that the average human is constantly traveling at roughly 930 mph (1,500 km/h). Those on the equator, however, get a tremendous amount of linear speed thanks to this rotation - roughly 1,000 mph (1,600 km/h). But if you were to stand on the north or south geographic poles, you wouldn't actually travel anywhere you would just spin around and around.
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