Predicting the solar wind
That field got its jumpstart in 1958 when Parker, an assistant professor at the time, submitted a paper to the Astrophysical Journal running through hydrodynamic calculations that showed if the temperature of the Sun’s outer atmosphere, the corona, is a million degrees, it must generate an outward flow of energetic particles moving at greater than 1 million miles per hour. Such fast-flying particles moving through our solar system had long been assumed from the way comets’ tails always point away from the Sun. But it was Parker’s calculations that solidly predicted such outflows, dubbed the solar wind, and furthermore proposed a valid physical mechanism to create it.
Of course, few people believed the validity of his work at first. In a 2018 interview with the University of Chicago, Parker said: “The first reviewer on the paper said, ‘Well I would suggest that Parker go to the library and read up on the subject before he tries to write a paper about it. Because this is utter nonsense.’”
According to the University of Chicago, the paper was nonetheless published when the journal’s editor, fellow faculty member Subrahmanyan Chandrasekhar, could find no fault with Parker’s calculations, despite the paper’s apparently outlandish claim.
Then, 1962, NASA’s Mariner II spacecraft encountered exactly the stream of outward-flowing particles in the inner solar system that Parker’s math had predicted — and those previously outlandish results ultimately became mainstream science knowledge.
But Parker’s work on the Sun didn’t stop there. Other major accomplishments during his long career include correctly predicting the spiral shape of the Sun’s magnetic field as it stretches into the outer reaches of the solar system, as well as the prediction that the solar corona is so unexpectedly and blisteringly hot because of nanoflares — the tiny, frequent cousins of bigger, more recognizable solar flares often pictured arcing away from the Sun’s surface.
Parker’s work included studying the magnetic fields not only of stars, but of entire galaxies as well. He also sought to understand how magnetic fields are generated and dissipated, and the many effects they can have on material along the way. Overall, including his 1951 Ph.D. thesis on interstellar dust and gas, Parker has 479 author results listed in the NASA Astrophysics Data System, which tracks science publications.
