NASA's Voyager spacecraft discovered something extraordinary at the edge of our Solar System — a superheated plasma “wall” reaching up to 50,000 kelvin. This region, known as the heliopause, marks the boundary between the Sun's solar wind and the interstellar medium. One by one, they both hit a 'wall of fire' at the boundaries of our solar system, measuring temperatures of 30,000-50,000 kelvin (around the same in Celsius) on their passage. . Now in interstellar space, these resilient spacecraft have sent back fascinating data, revealing unexpected conditions at the very edge of our solar system – including a region of surprisingly high temperatures, sometimes called a “hot wall.
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