How does the solar wind get heated as it leaves the Sun and approaches Earth? This is what a recent study published in Geophysical Research Letters hopes to address as a team of scientists from the United States and United Kingdom investigated the origin of solar wind and the processes responsible for heating it as it leaves the Sun. This study has the potential to help researchers better understand the formation and evolution of solar wind, while also gaining insight into space weather, which can wreak havoc on satellites and ground stations.
For the study, the researchers analyzed data obtained from NASA’s Parker Solar Probe, which is the closest spacecraft to travel to the Sun, having broken several of its own records for distance from the Sun. The goal of the study was to ascertain how the plasma that gets ejected from the Sun’s core to the Sun’s surface rapidly cools from 27 million degrees to approximately 10,000 degrees Fahrenheit, but then rapidly heats up to approximately 2 million degrees Fahrenheit as its journey continues outward through the Sun’s corona, which is the Sun’s outermost atmosphere.
In the end, the researchers discovered that the solar wind’s behavior is not as cut-and-dry as previously hypothesized, specifically regarding how the solar wind is heated by the plasma. This indicates longstanding models of how the solar wind behaves require updates. As noted, understanding space weather could have implications for determining how to protect satellites, ground stations, radio communications, and radiation exposure for astronauts and airplane passengers.
"We know there's this constant heat that's being input into the solar wind, and we want to understand what mechanisms are actually leading to that heating," said Dr. Kristopher Klein, who is an associate professor at the University of Arizona Lunar and Planetary Laboratory and lead author of the study. "We have made simplified models, we've run computer simulations, but by launching Parker Solar Probe, and by doing these detailed calculations of the structure of the velocity distribution of the particles, we can improve those models and calculate actually how the heating occurs at these at these extremely close distances where we have never measured before."
What new insight into the solar wind will researchers make in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!
Sources: Geophysical Research Letters, EurekAlert!
Featured Image: Artist's illustration of the Sun outer boudnary of its atmosphere. (Credit: CfA/Melissa Weiss)
