https://phys.org/news/2018-07-parker-solar-probe-birth.html

The solar wind fills our entire solar system. When gusts of solar wind arrive at Earth, they can set off dazzling aurora—but also expose astronauts to radiation, interfere with satellite electronics, and disrupt communications signals like GPS and radio waves. The more we understand the fundamental processes that drive the solar wind, the more we can mitigate some of these effects.

In 1958, Parker developed a theory showing how the Sun's hot corona—by then known to be millions of degrees Fahrenheit—is so hot that it overcomes the Sun's gravity. According to the theory, the material in the corona expands continuously outwards in all directions, forming a solar wind. A year later, the Soviet spacecraft Luna 1 detected solar wind particles in space, and three years after that, the observations were confirmed by NASA's Mariner 2 spacecraft.