How fast is the Earth moving through space?

Are you moving right now? While it may seem impossible, even if you are sitting perfectly still, you are moving through space, or rather, the Earth is moving through space with you on it. So, how fast is the Earth moving through the solar system, the galaxy, and the universe?

While we may often feel like we are at rest if we are not traveling, we are never truly at rest. First, the Earth is spinning on its axis, creating night and day as your location spins toward and away from the Sun.

While this spin is constant, it depends on your latitude. The circumference or distance around the equator of the Earth is about 24,898 miles (40,070 kilometers). To find this speed, you divide the circumference by the time it takes for the Earth to spin that far, 24 hours. Therefore, the spin speed at the equator is about 1,037 mph (1,670 km/h).

Without getting into the math, the spin speed decreases more as you go farther north or south since the Earth is wider at the equator than at the poles, and therefore a shorter distance to travel the same amount of time means a much slower speed, totaling only 0.00005 miles (0.00008 kilometers) per hour near the poles.

But that’s just how fast we’re spinning, if we want to look at how fast we are traveling through space, we have to start looking at our orbit.

How fast are we moving through the solar system? 

Using a similar equation to find speed as before, it takes about 365 days to complete an orbit around the Sun and the distance from Earth to the Sun (1 astronomical unit or 1AU) is 92,955,807 miles (149,597,870 kilometers). That is the radius (r) of our orbit, the distance traveled around the Sun. 

We can find the circumference of a circle with the following equation: 2 x ? x r. So in one year, Earth travels about 584 million miles (940 million km) using that equation. To get speed, we divide our distance, 584 million miles (940 million km), by­­ the time it takes for us to travel it 365.25 days (can’t forget that leap year!) and divide that result by 24 hours to get miles per hour or km per hour. 

Using these values, Earth travels about 1.6 million miles (2.6 million km) a day, or about 66,627 mph (107,226 km/h). NASA has officially calculated the average orbit velocity (speed) as 66,622mph (107,218km/h) due to using the most precise values possible and not rounding.

But Earth isn’t just moving around the Sun!

How fast are we moving through the galaxy?

The Sun and therefore our solar system is about 25,000 light-years from the center of our galaxy, the Milky Way, which is at least 100,000 light-years across.

Therefore, using the same equations again, we find that the solar system takes about 230 million years to travel all the way around the Milky Way.  Earth, along with the Sun and the rest of the solar system, appears to be moving at 124.3 miles (200 kilometers) per second, or at an average speed of 448,000 mph (720,000 km/h) according to observed data.

But our solar system isn’t just moving through the galaxy!

Image Credits: R. Hurt / JPL-Caltech / NASA

How fast are we moving through the universe?

Even the Milky Way is moving through space, actually heading on a collision course with its nearest neighbor, the Andromeda Galaxy approximately 2.5 million light years. The Milky Way and Andromeda are rushing toward each other at about 70 miles per second (112 km per second) and will collide in about 4 billion years. 

In addition, data from the Cosmic Microwave Background (radiation from the time immediately after the Big Bang) suggests that the universe is expanding at the rate of about 41.9 miles (67.5 kilometers) per second per megaparsec (a distance equivalent to 3.26 million light-years). 

All of these numbers are according to current research and measurements. It is important to remember that our exploration and understanding of space is always expanding, so these numbers may change slightly or even drastically with the discovery of new data.

Conclusion 

While we may not feel it, we are definitely moving through space, even right now while you are likely sitting and reading this article. 

In fact, you are spinning at up to 1,037 mph (1,670 km/h) if you live on the equator, you travel around the Sun at 66,627 mph (107,226 km/h), you travel around the galaxy at 448,000 mph (720,000 km/h), and you travel throughout the universe at about 70 miles per second (112 km per second) with an expansion rate of about 41.9 miles (67.5 kilometers) per second per megaparsec.

Something as simple as perceived versus real distance and speed can boggle the mind when looking at the universe. What will we discover next?