‘50,000°C firewall’: How Voyager fights the invisible shield protecting our solar system
The firewall helps scientists understand how our solar system interacts with interstellar space. Voyager’s data on plasma density and magnetic fields gives clues about how stars protect their planets.
The Firewall at the Edge
At the boundary of our solar system lies a transition zone where the Sun’s solar wind collides with particles of interstellar space. Scientists often call this turbulent layer the “firewall.”
Why 50,000°C Isn’t What It Seems
Measurements from Voyager suggest plasma in this region can reach tens of thousands of degrees. Yet because the gas is so thin, the spacecraft’s instruments don’t actually burn. The heat exists, but it cannot transfer in the same way it does on Earth.
Voyager’s First Encounter
When Voyager crossed this boundary in 2012, it picked up a sudden rise in plasma density. This confirmed that it had passed through the firewall and entered interstellar space.
The Invisible Shield
This firewall acts like a shield, blocking cosmic rays and charged particles from freely entering the solar system. Without it, Earth would be exposed to higher levels of radiation.
Voyager’s Defence
Voyager is not shielded by thick metal; instead, it survives because the plasma is so diffuse that the heat cannot damage its instruments. The spacecraft essentially “ignores” the temperature spike.
What We Learn from It
The firewall helps scientists understand how our solar system interacts with interstellar space. Voyager’s data on plasma density and magnetic fields gives clues about how stars protect their planets.
The Ongoing Journey
Even after four decades, Voyager continues to send back data from beyond this firewall, helping astronomers map the structure of our cosmic neighbourhood.
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