Astronomers found mysterious scar in space left by two stars 4.5-Million-Year-ago that nearly hit the Sun

A mysterious cosmic scar reveals two massive stars that passed near our solar system millions of years ago (Image: Leah Hustak)

Astronomers have discovered a mysterious scar in space that tells an ancient story. Millions of years ago, two massive stars passed close to our solar system, leaving behind a visible imprint in the surrounding gas. That missing scar is still detectable today.

The space around the Sun is not empty. It is filled with thin gas and dust, called the local interstellar medium. Inside this region, scientists have found a patch of unusually energized gas, forming a scar. This scar is unusual because helium and other atoms are far more ionized than expected.

By tracing stellar motions backward in time, astronomers identified Beta and Epsilon Canis Majoris, the two massive stars as the culprits. Roughly 4.5 million years ago, they passed unusually close to our solar system.

At that time, these stars were younger, hotter and far brighter than today’s Sun. Their ultraviolet radiation blasted nearby gas, creating a scar that remains detectable even millions of years later.

This cosmic scar helps explain a long-standing puzzle. The local interstellar medium is more energized than scientists’ models predicted. Understanding these encounters shows how stellar neighbors shape our solar environment, including cosmic rays, magnetic fields and radiation levels. Even our familiar Sun exists in a dynamic, ever-changing cosmic neighborhood.

The scar is more than a curiosity. It is a snapshot of our solar system’s history, revealing how stars from the galaxy influenced the space around us. Even empty space carries traces of energetic events, waiting to be decoded by curious scientists.