The question of “how fast are we moving” does not have a single, simple answer because motion is always relative. Speed is only meaningful when measured against a specific frame of reference. We are simultaneously participating in multiple layers of motion, with each larger cosmic structure contributing a significantly faster velocity. Our true speed is the result of compounding motion relative to the Earth, the Sun, the Milky Way, and the universe’s oldest light.
Speed Relative to Earth’s Axis
The most immediate speed we experience is generated by the Earth spinning on its axis once every 24 hours. This rotational velocity is not uniform across the planet’s surface, as it depends entirely on latitude. Since the Earth is widest at the equator, points there travel the greatest distance in a single day.
A person standing on the equator moves at approximately 1,670 kilometers per hour (1,040 miles per hour). The speed steadily decreases toward the poles, dropping to about 1,200 kilometers per hour at a mid-latitude city like New York. This difference in velocity is why space agencies prefer to launch rockets from sites closer to the equator, such as Cape Canaveral, to take advantage of the maximum initial eastward boost.
Speed Relative to the Sun
While the planet rotates, it is also engaged in a much faster orbital journey around the Sun. This revolution defines our year, as the Earth travels an elliptical path over 365 days. The average speed of the Earth in its orbit is approximately 107,000 kilometers per hour (67,000 miles per hour). The speed is not perfectly constant throughout the year because Earth’s orbit is an ellipse, not a perfect circle.
Earth moves slightly faster when it is closest to the Sun and slightly slower when it is farthest away. This immense orbital speed ensures that we travel roughly 940 million kilometers through space each year. This motion is a local speed, measured against the Sun, which itself is moving along with the rest of the solar system.
Our planet’s journey is a spiraling path, constantly looping around the Sun while the Sun carries us all forward.
Speed Relative to the Galactic Center
The Sun and its planetary system orbit the massive center of the Milky Way galaxy. Our solar system is located in one of the galaxy’s outer spiral arms, approximately 26,000 light-years from the center. This enormous orbit is the next major contribution to our total speed.
The Sun’s velocity around the galactic center is estimated to be about 230 kilometers per second, which translates to roughly 828,000 kilometers per hour (514,000 miles per hour). This motion is much harder to measure precisely than the Earth’s orbit, requiring observations of the relative motions of distant stars and gas clouds.
Even at this extreme speed, the vast scale of the Milky Way means that one full revolution takes an immense amount of time. The Solar System requires approximately 225 to 250 million Earth years to complete a single lap around the galaxy. Astronomers refer to this period as a “cosmic year,” and the Sun has completed only about 20 of these orbits since its formation.
Speed Relative to the Cosmic Microwave Background
The fastest and most universally referenced measure of our motion is relative to the Cosmic Microwave Background (CMB), the faint radiation left over from the Big Bang. The CMB is often considered a universal frame of rest because it permeates all of space and provides a reference point for the entire universe. Scientists measure our speed against the CMB by observing a phenomenon called dipole anisotropy.
This anisotropy is a subtle, yet measurable, temperature difference in the CMB across the sky. The direction we are moving toward appears slightly “warmer” because the photons are blueshifted by our motion. Conversely, the opposite side appears slightly “cooler” as the photons are redshifted, which is essentially a Doppler effect on a cosmic scale.
By measuring the magnitude of this temperature difference, astronomers calculate the speed of our motion through the universe. The entire Local Group of galaxies, including the Milky Way, is moving at approximately 630 kilometers per second relative to the CMB. This velocity, roughly 2.2 million kilometers per hour (1.4 million miles per hour), is the cumulative result of gravitational pulls from massive structures in our cosmic neighborhood.