Scientists Stunned by Discovery of 'Interstellar Tunnel': Connects Our Solar System to Other Stars

Space may seem like an empty, featureless place, but new research has shown that this is far from the case. Scientists have discovered an "interstellar tunnel" that connects our solar system to distant stars.

In a new study, scientists from the Max Planck Institute have identified two hot tunnels that stretch across vast swaths of space, the Daily Mail reports. The researchers collected thousands of measurements of the sky using the eROSITA X-ray telescope, a satellite launched in 2019. The study found that the sun sits at the center of a low-density bubble, about 300 light-years across, from which vast interstellar tunnels emerge. One channel extends toward the constellation Centaurus, passing through the surrounding cold regions of space. The other tunnel links our solar system to the constellation Canis Major.

The researchers believe that the two channels may be part of a larger, branching system that runs between different star-forming regions.

Scientists have long known that our solar system sits in a strange pocket of hot, less dense space known as the "local hot bubble." The region is thought to be a "supernova graveyard," formed by the explosions of dying stars 10 to 20 million years ago. When extremely massive stars burn through all their fuel, they collapse in on themselves, creating enough pressure to explode into supernovas. These explosions create a wave of hot plasma that sweeps up gas and dust, leaving behind a hot, low-density cavity, the Daily Mail reports.

The field was originally proposed to explain measurements of "soft X-rays" - photons that carry very small amounts of energy. Since these soft X-rays cannot travel very far in space without being absorbed, the fact that we can detect them suggests that there may be an X-ray-emitting plasma that has pushed everything else out of our way.

Using measurements from the eROSITA telescope, located 1.5 million km from our planet, scientists were able to measure these very faint traces of radiation without the influence of Earth's atmosphere. They combined them with measurements from the German ROSAT X-ray telescope, which was launched in 1990, to create the cleanest X-ray map of the universe ever made. However, these very sensitive measurements also revealed something strange.

By dividing the Milky Way into 2,000 different regions, the researchers realized that the north of the galaxy is significantly colder than the south. This means that the local hot bubble is moving away from the galactic disk in the direction of least resistance.

Study co-author Dr Michael Freiberg from the Max Planck Institute said: "This is not surprising, as was already established by the ROSAT survey. What we did not know was the existence of an interstellar tunnel to Centaurus, which cuts a hole in the colder interstellar medium."

This is in addition to a more precise measurement of a previously known interstellar tunnel leading to Canis Major, which is thought to run between the local hot bubble and the Gum Nebula, located 1,500 light years from Earth, the Daily Mail reports.

In their paper published in the journal Astronomy & Astrophysics, the researchers say this "hints at the possibility of a widespread network of tunnels connecting regions filled with the hot phase of the ISM [interstellar medium]." This interstellar network is maintained by the explosive birth and death of stars, which create powerful solar winds.

Previous studies have shown that the shock wave from the supernova that created the Local Hot Bubble collected gas and debris at its edge, creating conditions for new stars to form. These new stars then emit jets of hot gas and radiation that shoot outward until they reach other star-forming bubbles. This process, known as "stellar feedback," is thought to spread throughout the Milky Way, shaping the galaxy's structure.

The study also offers a fascinating hint about the origins of our own solar system. The researchers say our sun did not form inside the Local Hot Bubble, but just happened to enter it relatively recently.