For centuries, we have looked up at the night sky, wondering what lies beyond our home galaxy. The Milky Way, an enormous spiral galaxy spanning around 100,000 light-years, holds hundreds of billions of stars, countless planets, and possibly life beyond our own. But has anything created by humans—or even something connected to us in a more abstract way—ever made it beyond our galaxy’s grasp? The answer might surprise you.
What Does It Take to Leave the Milky Way?
Escaping the gravitational pull of the Milky Way is no small feat. To break free, an object must travel at an incredible escape velocity of 550 kilometers per second (340 miles per second). This is far beyond what any human-made spacecraft has achieved. However, nature has its own ways of hurling objects into intergalactic space.
Natural Ways Objects Can Escape Our Galaxy
1. Galactic Collisions and Mergers
The Milky Way has not always been the same as it is today. Around 8 to 11 billion years ago, it merged with another galaxy, Gaia-Enceladus, adding around 50 billion stars to our stellar population. These massive cosmic interactions can fling stars, planets, or even entire systems into intergalactic space.
2. The Power of Supernova Explosions
When a star explodes in a supernova, the immense force can propel companion stars or nearby planets at extreme speeds. Some of these so-called hypervelocity stars have been observed moving at nearly 1,000 kilometers per second, fast enough to escape the Milky Way’s gravitational pull.
3. Close Encounters with Black Holes
At the center of our galaxy lies a supermassive black hole, Sagittarius A*. Occasionally, stars that stray too close to this immense gravitational monster can be slingshotted out of the galaxy at incredible speeds. Some of these rogue stars have been observed racing toward intergalactic space, never to return (Harvard-Smithsonian Center for Astrophysics, 2019).
4. Passing Satellite Galaxies
The Milky Way has around 59 known satellite galaxies, including the Large and Small Magellanic Clouds. Some of these galaxies pass through or interact with the Milky Way’s disk, and in the process, stars or other celestial objects can be thrown into deep space.
Has Anything Human-Made Left the Milky Way?
Now, let’s return to the original question. Have we, as humans, sent anything beyond the Milky Way? Technically, no physical spacecraft has made it even close. The farthest human-made objects, Voyager 1 and Voyager 2, are still within our galactic neighborhood, only about 23 and 20 billion kilometers away, respectively (NASA JPL, 2023). That’s still deep inside the Milky Way.
However, in a more abstract sense, something we created may have already reached beyond our galaxy.
The First Human-Made Light to Leave the Milky Way
The speed of light is the ultimate speed limit of the universe. Every light wave that leaves Earth, whether from the Sun reflecting off the ocean, a radio signal from a spacecraft, or the glow of a distant fire, travels at 300,000 kilometers per second (186,000 miles per second). This means that any light emitted by early human fires or primitive torches could have traveled vast distances by now.
Homo sapiens have only existed for about 200,000 to 300,000 years, which is a blink of an eye in cosmic terms. However, our ancestors, including species like Homo habilis and Homo erectus, were making fire long before that. Some studies suggest early humans may have been controlling fire as far back as 1.5 to 2 million years ago (Smithsonian Institution, 2022).
If so, the first photons produced by our ancient fires have already traveled at least 1.5 to 2 million light-years—meaning they could now be reaching the Andromeda Galaxy, the closest major galaxy to the Milky Way.
The Cosmic Echo of Humanity
So while no spacecraft, astronaut, or physical object made by human hands has left the Milky Way, something created by our species—a tiny, flickering flame from an early fire—may have already escaped into the vastness of intergalactic space. This thought connects us not only to the cosmos but to the long, unbroken lineage of our ancestors. It’s a humbling reminder that in some way, we have already sent something beyond our galaxy—something fragile, yet enduring.
Our reach into the universe is just beginning. With advancing technology, it is not impossible to imagine a future where a spacecraft, or even a human, truly leaves the Milky Way. Until then, we can look up at the night sky knowing that some tiny part of us has already made the journey.
