Scientists and space organizations have been wanting to study the Sun to learn about the star’s composition and its corona, which is another name for its atmosphere, for the longest time. Although researchers have estimated information about the star that powers our solar system, they made some new discoveries recently, thanks to NASA’s Parker Solar Probe that “touched the Sun” for the first time in humanity’s history.
The man-made spacecraft, made with high-temperature-resistant (up to 1.8 million-degree Fahrenheit) carbon blocks, entered the Sun’s atmosphere back in April this year. Details about the mission, however, were recently announced at a press conference at the Fall session of the American Geophysical Meeting in New Orleans last week. The delay in the announcement was caused as NASA needed time to confirm the feat achieved by the Parker Solar Probe. So, since its initial flyby, NASA’s solar probe has encountered the Sun two more times in August and November.
“Not only does this milestone provide us with deeper insights into our Sun’s evolution and its impacts on our Solar System, but everything we learn about our own star also teaches us more about stars in the rest of the universe,” Thomas Zurbuchen, the associate administrator for the Science Mission Directorate, said in a press release.
More details about the mission were recently published in a paper in Physical Review Letters, while another paper, relating to the Parker Solar Probe, is scheduled to be published in The Astrophysical Journal soon.
Now, coming to the new discoveries, when the probe entered the solar atmosphere, 8.1 million miles above the surface of the Sun, for the first time in April, it discovered that the Alfvén critical surface, which is the space between the Sun’s atmosphere and the space, is not uniform in shape.
Previously, scientists estimated that this dividing line was somewhere between 4.3 and 8.6 million miles above the Sun’s surface, which is also called the Photosphere. The discovery by the solar probe revealed that the line is not uniform and has peaks and valleys. At its closest, the Parker Solar Probe was able to reach 6.5 million miles above the Sun’s surface.
Other than this, during its fly-by maneuvers, the solar probe also discovered two new phenomena of the Sun, namely switchbacks and pseudostreamer. While switchbacks are streams of charged particles, escaping the Sun’s surface in a zig-zag pattern, pseudostreamers are these huge structures that are similar to the “eye of the storm”, due to their calm nature.
The Parker Solar Probe will continue to monitor the Sun by leveraging Venus flybys, which act as slingshots to get the spacecraft inside the Sun’s corona. The next Venus flyby for the Parker Solar Probe is scheduled for 2023, and it will take it to 3.83 million miles above the Sun’s surface.