Galaxies very close to the Milky Way, like Andromeda, are actually moving toward us, not away, while most distant galaxies are receding rapidly due to cosmic expansion.
How fast are galaxies moving away from us?
Galaxies recede at about 73 kilometers per second per megaparsec (with a small spread in estimates: 67–73 km/s/Mpc).
Picture this: a galaxy one megaparsec away—roughly 3.26 million light-years—zooms off at 73 km/s. Double the distance? You’re looking at 730 km/s. That’s because space itself is stretching, carrying galaxies along for the ride. (Think of dots on a balloon inflating—farther dots move apart faster, even though none are actually "moving" through the rubber.)
Are galaxies moving away from us?
Yes, galaxies outside the Local Group are moving away from us, and the most distant appear to recede fastest.
Here’s the thing: it’s not that galaxies are zooming through space. Space itself is expanding, carrying galaxies along like raisins in rising bread dough. Each raisin sees others moving away, and the farther ones move faster. Our Local Group—Milky Way, Andromeda, and about 80 smaller galaxies—is stuck together by gravity and isn’t expanding.
Are all galaxies moving away from us at the same speed?
No—galaxies recede at speeds proportional to their distance, following the Hubble-Lemaître law.
At about 18 billion light-years out, galaxies seem to zip away faster than light. Don’t panic—this doesn’t break relativity because it’s space stretching, not the galaxies themselves moving through space. Send a photon today toward a galaxy beyond that distance? It’ll never arrive. The gap grows faster than light can cross it—a cosmic "horizon" effect.
Does the Milky Way move fast or slow?
The Milky Way moves at about 1.3 million miles per hour (2.1 million km/h) relative to the cosmic microwave background rest frame.
That’s 600 km/s—fast enough to circle Earth in about 3 minutes. Most of that motion comes from being pulled toward the Virgo Cluster and the Great Attractor. It’s not "slow," but it’s also not the fastest thing in our galaxy. Our local neighborhood orbits the galactic center at a leisurely 130 miles per second (210 km/s).
What galaxy is moving towards us?
The Andromeda Galaxy (M31) is moving toward the Milky Way at about 70 miles per second (110 km/s).
It’s the only major galaxy in our Local Group heading our way, though dozens of smaller dwarf galaxies are also approaching. Andromeda is bright enough to see with the naked eye under dark skies, appearing as a fuzzy patch in the constellation Andromeda. Don’t lose sleep over it—the merger won’t start for another 4 billion years.
Why are galaxies moving towards us?
Gravity overcomes cosmic expansion on small scales, pulling galaxies toward each other.
On large scales, the universe’s expansion wins. But locally? Gravity rules. Andromeda feels our combined gravity more strongly than the stretching of space. When light from a galaxy like M90 gets compressed as it approaches (a blueshift), it’s because the galaxy is falling inward, shortening the wavelength of its starlight—like squeezing a spring. This is the opposite of the redshift we see from distant, receding galaxies.
Where do we find the fastest moving galaxies?
The fastest-moving objects are found near supermassive black holes, like Sagittarius A*
Stars orbiting the Milky Way’s central black hole reach speeds over 8% of light speed—more than 50 million mph. These stars, like S2, whip around Sgr A* in just decades, letting astronomers test Einstein’s general relativity. Farther out, the fastest whole galaxies are those flung from galaxy clusters during gravitational slingshots, reaching thousands of kilometers per second. The current record-holder is CGCG 97-079, clocked at over 1,500 km/s relative to its cluster.
Do galaxies travel faster than light?
Galaxies beyond about 18 billion light-years appear to recede faster than light, but this is due to space expanding, not motion through space.
Special relativity still holds locally: nothing moves through space faster than light. But the expansion of space itself isn’t bound by that limit. Think of two points on a rubber sheet being pulled faster than an ant can crawl—the sheet stretches, but the ant doesn’t break any speed laws. The “Hubble sphere” marks the distance where recession speed equals light speed; beyond it, galaxies fade from view forever.
What is outside the universe?
There is no “outside” of the universe as we define it—space, time, and all energy are contained within.
If the universe is everything that exists, there’s nothing left to occupy a “place” beyond it. You might imagine the cosmos as the surface of an inflating balloon: the rubber has no edge or outside, only an expanding two-dimensional surface. Some theories suggest a “multiverse,” but those exist within the same spacetime framework, not outside of it. Any question about “outside” assumes a larger container that doesn’t exist in standard cosmology.
What is the fastest thing in the universe?
Photons in a vacuum travel at the speed of light, about 670 million miles per hour
That’s the cosmic speed limit set by relativity. Lasers, gamma rays, and radio waves all move at this speed. While exotic concepts like “tachyons” or warp drives get tossed around in sci-fi, no confirmed particle or effect outpaces light in a vacuum. Even the fastest cosmic rays, protons hurtling at near-light speeds, are still slower than pure photons.
Is the Milky Way moving through space?
Yes, the Milky Way rotates and moves through space at high speed.
The galaxy spins once every 230 million years at our solar system’s location, carrying stars, gas, and planets along like horses on a merry-go-round. Meanwhile, the entire galaxy drifts at 1.3 million mph toward the Virgo Cluster. Imagine a frisbee spinning while being thrown across a field—both motions are real and measurable. Even the Local Group as a whole has a peculiar velocity relative to the cosmic microwave background.
How fast is the Milky Way expanding?
Your question mixes concepts: the Milky Way isn’t expanding—it’s moving
The Milky Way is a gravitationally bound system, so its stars and gas aren’t flying apart. What *is* expanding is the space between galaxy clusters, described by the Hubble constant. The Milky Way’s motion is about 1.3 million mph toward the constellation Leo/Virgo, not an expansion rate. If you meant how fast the universe is expanding, that’s the Hubble constant: roughly 73 km/s per megaparsec as of 2026.
Will the Milky Way collide with Andromeda?
Yes—Andromeda and the Milky Way will merge in about 4.3 billion years
Simulations show the galaxies will first pass closely, then merge fully about 6 billion years from now. During the encounter, individual stars rarely collide, but their orbits will be scrambled. The result will be a single, larger elliptical galaxy nicknamed “Milkomeda.” Star formation will spike during the merger, and our night sky will never look the same. The Sun has a good chance of being flung farther from the new galactic core.
Is the Milky Way moving further away from other galaxies?
Most galaxies are moving away, but the Local Group’s galaxies are not
Galaxies in the Local Group—including Andromeda, the Magellanic Clouds, and dozens of dwarfs—are gravitationally bound to the Milky Way, so they’re not drifting apart. In fact, some are coming closer. Beyond the Local Group, nearly every galaxy is receding due to cosmic expansion, with speed increasing with distance. Voyager 1, our farthest spacecraft, won’t reach another star for tens of thousands of years, let alone another galaxy.
Is the Milky Way blue shifted?
No—the Milky Way is not blue shifted overall
Despite its high peculiar velocity, the Milky Way’s motion isn’t enough to make its observed starlight blueshifted across the sky. Blueshift only dominates in a small region around galaxies like Andromeda (due to its approach). Almost every other galaxy shows a redshift, indicating recession. Our local motion is measured relative to the cosmic microwave background, where we’re heading toward a point in the constellation Crater, but that doesn’t mean we’re blue shifted as a whole.
