Sixty years after NASA set the goal, and three years after its Parker Solar Probe launched, the spacecraft has become the first to “touch the sun.” The Parker Solar Probe has successfully flown through the sun’s corona, or upper atmosphere, to sample particles and magnetic fields.
The announcement was made at the 2021 American Geophysical Union Fall Meeting in New Orleans on Tuesday, and research from the solar milestone has been published in the Physical Review Letters.
The Parker Solar Probe launched in 2018 and set out to circle closer and closer to the sun. The sun’s corona is much hotter than the actual surface of the star, and the spacecraft could provide insight about why. The corona is one million degrees Kelvin (1,800,000 degrees Fahrenheit) at its hottest point, while the surface is around 6,000 Kelvin (10,340 degrees Fahrenheit).
The spacecraft has already revealed surprising finds about the sun. Before Parker Solar Probe’s mission is done, it will have made 21 close approaches to the sun over the course of seven years. The probe will orbit within 3.9 million miles of the sun’s surface in 2024, closer to the star than Mercury — the closest planet to the sun. Although that sounds far, researchers equate this to the probe sitting on the four-yard line of a football field and the sun being the end zone. When closest to the sun, the 4½-inch-thick carbon-composite solar shields will have to withstand temperatures close to 2,500 degrees Fahrenheit. However, the inside of the spacecraft and its instruments will remain at a comfortable room temperature. “Flying so close to the Sun, Parker Solar Probe now senses conditions in the magnetically dominated layer of the solar atmosphere — the corona — that we never could before,” said Nour Raouafi, Parker project scientist at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, in a statement. “We see evidence of being in the corona in magnetic field data, solar wind data, and visually in images. We can actually see the spacecraft flying through coronal structures that can be observed during a total solar eclipse.”