A new study conducted by researchers at the University of Minnesota Twin Cities, using data from NASA’s Parker Solar Probe, provides new insight into what causes and accelerates the solar wind, which is a stream of charged particles emitted from the Sun’s corona. The findings are published in the journal Science.
Science can benefit from a better understanding of how the solar wind works because it can help them predict “space weather,” or the response to solar activity (such as solar flares) that can have a negative impact on astronauts in space as well as much of the technology that people on Earth rely on.
The paper appeared in Astrophysical Journal Letters (“Parker Solar Probe evidence for the absence of whistlers close to the Sun to scatter strahl and to regulate heat flux”).
Parker Solar Probe, the Spacecraft that Explores the Sun
A new study done by academics at the University of Minnesota Twin Cities, utilizing data from NASA’s Parker Solar Probe, reveals fresh insight into how solar wind is created and accelerated throughout the solar system.
Specifically, the researchers analyzed data collected by the Parker Solar Probe, which was launched in 2018 with the purpose of assisting scientists in understanding what warms the Sun’s corona (the outer atmosphere of the Sun) and creates the solar wind.
In order to address these concerns, scientists must first comprehend the processes through which energy from the Sun is transferred.
Data from the most recent batch of observations was gathered in August 2021 at a distance of 4.8 million miles from the Sun, making it the closest a spacecraft has ever been to the solar.
Previous research has indicated that electromagnetic waves known as “whistler” waves can be found in the solar wind at distances ranging from about 35 solar radii (one solar radius is a little more than 432,000 miles) out to the Earth’s orbit at about 215 solar radii and that these waves can help regulate the heat flux, which is one type of energy flow.
At this new study, a research team led by the University of Minnesota determined that whistler waves do not exist in a region closer to the Sun, within around 28 solar radii.
Instead, the researchers saw a distinct kind of wave, one that was electrostatic rather than electromagnetic.
Moreover, in the exact location, they discovered something else: the electrons exhibited the effects of an electric field generated in part by the gravitational pull of the Sun, a phenomenon similar to that which occurs near the Earth’s poles, where the “polar wind” is accelerated.
According to our findings, the whistlers are no longer detectable as we reach within 28 solar radii.
Therefore, according to Cynthia Cattell, the primary author of the work and professor at the University of Minnesota Twin Cities School of Physics and Astronomy, whistlers can’t regulate the heat flow in that location. She added that this conclusion came as a complete and utter surprise to everyone.
It has implications not just for knowing the solar wind and the winds of other stars. Still, it is also critical for understanding the heat flow of various other astrophysical systems. We cannot deploy satellites, such as the formation of star systems.
Solar Wind Linked To Other Phenomena
Scientists are interested in learning more about solar wind for a variety of additional reasons.
The disturbance of the Earth’s magnetic field may result in “space weather” occurrences that can cause satellites to fail, communication and GPS signals to be disrupted, as well as power outages on the ground in northern latitudes such as Minnesota, among other things.
Solar wind energetic particles may be hazardous to astronauts who are going through space because of their high energy.
According to Cattell, the ability to anticipate space weather is something that scientists seek.
It is also impossible to estimate how quickly the solar wind will be flowing or its density when it reaches the Earth if you don’t understand the specifics of energy flow near to the Sun, as stated by the scientist.
These are some of the characteristics that influence how we are affected by solar activity.
After flying to an even closer distance from the Sun, the Parker Solar Probe will return in late 2024, at a distance of just 3.8 million miles.
Cattell and her colleagues are looking forward to receiving the next batch of data from the spacecraft in the coming months.
Scientists want to determine why there are no whistler waves near the Sun, how electrons propelled by the gravity-associated electric field could ignite other waves, and how this will affect the solar wind in the coming years.
