NASA’s Parker Solar Probe touched the sun for the first time as it spent five hours in the upper solar atmosphere, known as the crown. It is the first time that a human construct has crossed the outer limits of the sun and made the first direct observations of phenomena such as particles, magnetic forces, and others, for which until now only estimates could be made by scientists.
The Parker Solar Probe is the Alter Ego of NASA’s Voyager spacecraft Twin. The latter are the human constructions that have traveled farther from the sun (and the earth) than any other spacecraft to date, leaving behind the solar realm, that is, the area of space to which the “breath” of the sun reaches, the solar wind.
In contrast, the Parker Solar Probe has come closer to the heart of the solar system than any other human engine. The achievement, described as historic by NASA, occurred on April 28, 2021 and was announced now – it took a long time for the data to be obtained and thoroughly analyzed – by scientists at a press conference at the American Geophysical Union (AGU) conference and related publication in the journal “Physical Review Letters”. According to lead researcher Professor Justin Casper of the University of Michigan, the event marks the achievement of the mission’s primary goal and a new era in understanding the crown’s physics.
The spacecraft was launched in 2018 with the aim of studying the sun at a closer distance than any other spacecraft in the past, something it has achieved after successive ever shorter transits (it will make a total of 24 transits). Its entry into the solar corona, beyond the so-called “Alfven limit”, at an altitude of about 13 million km from the visible surface of the sun (the photosphere), was achieved during its eighth near passage through our star.
The $ 1.5 billion Parker, which is, among other things, the fastest man-made object, traveling at more than 500,000 kilometers per hour, has already made several important discoveries.
The solar corona hides a mystery that demands explanations. More specifically, while in the lower photosphere, which is closer to the heart of the sun, the temperature reaches about 6,000 degrees Celsius, in its atmosphere (in the solar corona), which is higher, the temperature can reach several million degrees Celsius. Also, inside the corona the discharge of charged solar particles (electrons, protons and heavy ions) suddenly accelerates and is converted into ultrasonic solar wind, a process that is also not well understood to date.
The next step for the spacecraft will be to go even deeper into the atmosphere of the sun and stay there for a longer time. Finally, in 2025, Parker is planned to reach a distance of only 6.2 million kilometers from the photosphere itself. The information it will gather will help, among other things, to better predict the future of space weather and magnetic “storms” caused by the sun, which, unlike the earth, has no solid surface at all.
