Voyager 1 has sent a message from a strange location in space 20,000 lakh km away that's as hot as 50,000°C, but without fire

NASA’s Voyager 1 and Voyager 2 spacecraft, launched in 1977, have identified a high-temperature region beyond the edge of the solar system. Scientists are now studying this area, nicknamed the "firewall", which may lead to a new understanding of the solar system’s boundary and the magnetic connections between interstellar and solar space.

The Voyager probes were launched over four decades ago to explore planets and move beyond the solar system into interstellar space. Despite being launched at a time when the internet was in its infancy and cassette-based Walkmans were popular, the spacecraft continue to send data back to Earth.

NASA sent Voyager 1 and Voyager 2 with the goal of reaching the farthest regions of space. Over the years, they have provided important information about the outer planets, and now, about the space that lies beyond our solar system.

Where does the solar system end?

There has long been debate among scientists about where the solar system truly ends. While some suggest it ends after Neptune, others point to the Oort Cloud—a distant region believed to house comets.

NASA defines the boundary of the solar system as the heliopause. This is the point where the solar wind, a stream of charged particles from the Sun, loses its strength. Beyond this point lies interstellar space. NASA compares the heliopause to the edge of a bubble formed by the Sun’s influence.

Voyager 1 makes the ‘firewall’ discovery

After crossing the heliopause, both Voyager probes encountered an extremely hot region, where temperatures range between 30,000 and 50,000 degrees Celsius. This region has been informally named the “firewall.”

Despite the extreme heat, the probes remained unharmed. NASA explains that this “firewall” is not made of fire in the traditional sense. Instead, it contains highly energetic particles that are very spread out. They carry significant energy but don’t burn as flames do.

New questions for space science

After passing through this high-energy zone, the probes recorded magnetic field data from interstellar space. Scientists noticed that the magnetic fields beyond the heliopause seemed to stay connected to the fields within the solar system. This challenges earlier beliefs that the two regions were completely separate.

This finding has raised new questions:

• Is there a connection between the magnetic fields inside and outside the solar system?
• Does the Sun’s influence extend farther than previously believed?
• Are there still unknown factors about the galaxy’s magnetic structure?

Why these findings matter

Even though these discoveries happen far from Earth, they are important for space science. The continuous operation of Voyager 1 and 2 since 1977, and their ability to report new information, highlights the long-term success of these missions.

With over 2 billion kilometers behind them, the Voyager spacecraft are helping scientists understand more about the structure and limits of the solar system. Each new discovery reminds us that the universe remains full of unknowns still waiting to be explored.