Our Solar System Is Surrounded By An 89,000°F Wall of Plasma

 

NASA’s Voyager 2 space probe, launched in 1977, has sent us some fascinating and unexpected data. In 2018 it began passing through the heliopause, a region surrounding our solar system. Here, the probe discovered a wall of interstellar plasma, something like a shield of fire-like gas made of solar-wind.

This sphere of piping hot plasma is low density, so Voyager 2 can pass right through it. However, as far as cosmic radiation is concerned, the wall of interstellar plasma is like a physical barrier, blocking 70% of the radiation from getting into our solar system. As soon as the wall is breached, we step into interstellar space where the level of cosmic radiation spikes. If it weren’t for the heliosphere’s solar-wind shield, all that radiation would strike us here on Earth.

Credit: NASA/Walt Feimer

According to the measurement of temperature taken by the probe, the wall of hot plasma is between 30,000 to 50,000 kelvins, which is roughly 53,000 to 89,000 degrees Fahrenheit. A paper published on the matter in the journal Nature Astronomy explained:

The [very local interstellar medium, a.k.a. the wall of hot plasma] is variable near the [heliopause] and hotter than expected. Voyager 2 observations show that the temperature [in that region] is 30,000–50,000 K, whereas models and observations predicted a [very local interstellar medium] temperature of 15,000–30,000 K.

Credit: NASA/JPL-Caltech

NASA is not sure if, and how, this wall of hot plasma will make interstellar travel. They do plan to venture out beyond our solar system someday, after all. Although, the fact that both Voyager 1 and 2 are seemingly making it through ok (and they are over 40-year-old pieces of equipment, let’s not forget) is a good sign, at least for the spaceshipsFor now, there’s no way of knowing how the radiation would affect biological beings. Nevertheless, the discovery is impressive! A human-made device has reached the environment created by our sun, where our solar system ends, and the boundless ocean of interstellar space begins.

Below is a very informative and easy to understand video by science teacher Anton Petrov. He explains everything about the “wall of fire,” the heliosphere, interstellar space, and the two Voyager space probes.