The Expanding Universe: How Fast Are We Really Moving Through Space?

Understanding the expanding universe begins with one of the most important discoveries in modern astronomy: Edwin Hubble’s observation that galaxies are moving away from us, and that the farther a galaxy is, the faster it appears to recede. This relationship, known as Hubble’s Law, provided the first strong evidence for the Big Bang theory—the idea that the universe began as a hot, dense point and has been growing ever since.

What surprises many people is that galaxies are not actually “flying” through space at extreme speeds. Instead, space itself is stretching, and galaxies are simply moving along with it like raisins in rising bread dough. This means the distances between galaxies increase even though they may not be moving on their own.

So, how fast are we moving? The answer depends on how you measure motion in the universe. On Earth, we already move at incredible speeds without noticing. Our planet rotates at over 1,600 km/h, orbits the Sun at 107,000 km/h, and our Solar System travels around the Milky Way at approximately 828,000 km/h. But on an even grander scale, our entire Milky Way galaxy is hurtling toward the “Great Attractor,” a mysterious gravitational concentration in deep space.

Even more mind-blowing is that due to the universe’s expansion, distant galaxies are moving away from us faster than the speed of light—not because they break physics, but because the fabric of space expands between us. This is allowed within general relativity.

The expansion of the universe also helps explain the cosmic microwave background (CMB)—radiation leftover from the Big Bang. When we observe the CMB, we see tiny temperature variations that reveal how matter was distributed in the early universe. These patterns eventually grew into galaxies, stars, and planets through gravitational attraction.

Another fascinating question is whether the universe will continue expanding forever. Current observations show that not only is the universe expanding, but the expansion is accelerating. Scientists attribute this mysterious behavior to dark energy, an invisible force that makes up nearly 70% of the universe. Although we don’t yet understand dark energy, its effects dominate the universe’s future.

If the expansion continues indefinitely, distant galaxies will eventually disappear from view. Future observers, billions of years from now, will see a darker, emptier universe. But for us today, we live at the perfect time to study distant galaxies and understand the cosmos.

The expanding universe is not just a scientific concept—it is a story of movement, energy, and evolution. Every second, space grows larger, carrying galaxies like boats on a cosmic ocean. Understanding this expansion helps answer some of humanity’s biggest questions: Where did we come from? Where are we going? And what is the destiny of the universe?

The more we learn, the more we realize that our cosmic journey is far bigger and faster than anything we experience on Earth. And yet, we remain connected to the universe, shaped by its forces, and inspired by its mysteries.

The universe is far from still. It stretches, grows, and transforms every second in ways that challenge everything we know about reality. When astronomers talk about the “expanding universe,” they do not mean that galaxies are simply drifting away from each other. Instead, space itself—the fabric of the cosmos—is stretching like elastic. This remarkable idea forms the foundation of modern cosmology, but understanding it requires us to rethink motion, distance, and even time.

The story begins in the early 20th century, when astronomer Edwin Hubble made a revolutionary discovery. By measuring the light of distant galaxies, he noticed something unusual: galaxies farther away from Earth had light shifted toward the red end of the spectrum, a phenomenon known as redshift. The farther the galaxy, the greater the redshift. Hubble realized this could only mean one thing—the universe is expanding, and everything is moving away from everything else.

This discovery supported the then-new idea of the Big Bang theory, which states that the universe began around 13.8 billion years ago as an incredibly hot, dense point. Since that moment, space has been expanding, carrying galaxies with it like dust floating apart as a balloon inflates.

But this raises an interesting question: how fast are we, right now, moving through space?

Most of us feel perfectly still as we sit in our homes or walk down the street, but this is only an illusion. The truth is that Earth, the Solar System, and the entire Milky Way galaxy are traveling through the cosmos at unimaginable speeds—yet because everything around us moves together, we do not feel it.

To understand this motion, it helps to break it down step by step:

1. Earth’s Rotation

Our planet spins on its axis, making one full rotation every 24 hours. At the equator, this means a speed of about

1,670 kilometers per hour (1,040 mph).

2. Earth’s Orbit Around the Sun

Earth also travels around the Sun at a breathtaking speed of

107,000 kilometers per hour (67,000 mph).

3. The Solar System’s Motion Through the Milky Way

The Sun is not stationary. It moves around the center of the Milky Way galaxy at approximately

828,000 kilometers per hour (514,000 mph).

4. The Milky Way’s Motion Through the Universe

Our entire galaxy is moving toward a gravitational anomaly called the Great Attractor, traveling at:

2.1 million kilometers per hour (1.3 million mph).

What’s even more astonishing is that these motions stack on top of each other. We are constantly moving through the universe in multiple directions at once, like a passenger on a train that is also on a spinning Earth that orbits the Sun, all while the galaxy hurtles through space.

Yet this motion is small compared to the expansion of the universe.

Why Expansion Is More Than Motion

When we say galaxies are moving away from us, it might sound as if they are traveling through space like rockets. But that is not what is happening. Instead, space itself is stretching, causing galaxies to appear farther apart over time.

A popular analogy is the “raisin bread model.” When dough rises, the raisins remain in place inside the dough, but as the dough expands, the distance between raisins increases. The raisins aren’t moving; the dough is. Our galaxies are the raisins, and space is the dough.

This is why some galaxies appear to move away from us faster than the speed of light. This does not break the laws of physics because the galaxies aren’t moving through space faster than light—space itself is expanding, carrying them along.

Evidence from the Cosmic Microwave Background

One of the strongest pieces of evidence for the expanding universe is the cosmic microwave background (CMB)—a faint glow that fills the entire universe. It is the leftover heat from the Big Bang, now cooled to just 2.7 degrees above absolute zero. When scientists map the CMB, they observe tiny temperature variations that show how matter was distributed in the early universe.

These initial fluctuations eventually grew into galaxies, stars, and planets. In other words, the CMB is a snapshot of the universe as an infant, revealing the seeds of cosmic structure.

Dark Energy: The Force Behind Accelerated Expansion

For decades, scientists believed the universe’s expansion was slowing due to gravity. But in 1998, astronomers studying distant supernovas discovered something shocking: the expansion of the universe is accelerating.

To explain this unexpected behavior, scientists proposed the existence of dark energy—a mysterious force that makes up about 70% of the universe. We don’t know what dark energy is, but we see its effects clearly. It pushes galaxies apart faster and faster, shaping the universe’s future.

If dark energy continues driving expansion at the current rate, distant galaxies will eventually move out of sight entirely. Billions of years from now, future astronomers may only see the few galaxies gravitationally bound to the Milky Way.

We are living at a special moment in cosmic history—one where we can still observe the wider universe.

What Is the Future of the Expanding Universe?

Scientists have proposed three main possibilities:

1. Eternal Expansion (Most Likely)

The universe continues expanding forever, becoming colder and emptier until galaxies fade and stars die.

2. The Big Crunch

If dark energy weakens, gravity might reverse expansion and collapse the universe back into a dense point. Current evidence suggests this is unlikely.

3. The Big Rip

If dark energy becomes stronger over time, it could tear apart galaxies, stars, planets, and eventually atoms themselves. This is speculative but fascinating.

A Universe in Motion

The expanding universe reminds us that we are part of a dynamic cosmic story. Everything—from galaxies to atoms—participates in this grand movement. We are traveling through space at incredible speeds, riding the wave of expanding spacetime that began billions of years ago.

Yet despite the vastness and motion of the cosmos, we humans have developed the science, tools, and imagination to understand it. The more we explore, the more we realize that the universe is not static but alive with energy, growth, and endless myster