Parker Solar Probe finds magnetic energy near the sun propels solar windas scientists have achieved a significant breakthrough in understanding the solar wind, the high-speed stream of charged particles emitted by the sun. This groundbreaking research, using data collected by NASA's Parker Solar Probe, sheds light on the mechanisms driving the solar wind and holds crucial implications for our planet.
Through a study published in the journal Nature, a team of researchers, led by James Drake, a Distinguished University Professor in the University of Maryland’s Department of Physics and Institute for Physical Science and Technology (IPST) and Stuart Bale from UC Berkeley, has unraveled the mystery behind the solar wind's ability to reach speeds exceeding 1 million miles per hour.
The solar wind plays a vital role in shaping our solar system's dynamics, as it forms a protective magnetic bubble known as the heliosphere. This expansive shield safeguards our planetary system from the onslaught of high-energy cosmic rays that pervade the galaxy. However, the solar wind also carries plasma and fragments of the sun's magnetic field, which can interact with Earth's magnetosphere, leading to disruptive events such as geomagnetic storms.
Geomagnetic storms occur during heightened solar activity, characterized by solar flares and coronal mass ejections. While these storms create mesmerizing auroras near the Earth's poles, their extreme potency can pose severe risks. Power grid failures, disruptions to global communications, and potential harm to astronauts in space are some of the repercussions associated with these powerful space weather events.
“Winds carry lots of information from the sun to Earth, so understanding the mechanism behind the sun’s wind is important for practical reasons on Earth,” Drake said. “That’s going to affect our ability to understand how the sun releases energy and drives geomagnetic storms, which are a threat to our communication networks.”
Earlier studies hinted at the sun's magnetic field as a driving force behind the solar wind, but the exact mechanism remained elusive. Earlier this year, James Drake and his colleagues proposed that magnetic reconnection, a process of magnetic fields aligning and releasing tremendous energy, plays a pivotal role in heating and accelerating the solar wind.
The team discovered that the sun's surface is adorned with small "jetlets" of scorching plasma, propelled upward by magnetic reconnection. Leveraging data from the Parker Solar Probe, which ventured closest to the sun's corona, the outermost and hottest layer, the researchers gained unprecedented insights into the bursts of magnetic energy emanating from coronal holes, the openings in the sun's magnetic field that give rise to the solar wind.
According to Drake:
Two things pointing in opposite directions often wind up annihilating each other, and in this case doing so releases magnetic energy. These explosions that happen on the sun are all driven by that mechanism. It’s the annihilation of a magnetic field.- James Drake, a Distinguished University Professor in the University of Maryland’s Department of Physics and Institute for Physical Science and Technology (IPST)
The Parker Solar Probe moving close to the sun
The authors of the recent Nature paper sought to gain a deeper understanding of certain mechanisms by utilizing data obtained from the Parker Solar Probe. This data was used to analyze the plasma emanating from the sun's corona, which is its outermost and hottest layer.
The Parker Solar Probe achieved a significant milestone in April 2021 by becoming the first spacecraft to enter the sun's corona and has been progressively approaching the sun since then. The specific dataset referenced in the paper was collected when the probe was located approximately 5.6 million miles away from the sun, equivalent to a distance of 13 solar radii.
In a remarkable finding, the scientists determined that the process of interchange connection, a continuous magnetic reconnection occurring between open and closed magnetic fields, powers the release of magnetic energy. This energy release drives the outward flow of superheated plasma, overpowering the sun's gravity and enabling the generation of the fast solar wind.
“When you get very close to the sun, you start seeing stuff that you just can’t see from Earth,” Drake said. “All the satellites that surround Earth are 210 solar radii from the sun, and now we’re down to 13. We’re about as close as we’re going to get.”
Understanding these frequent energy releases on the sun's surface holds the key to comprehending and potentially predicting more hazardous eruptions that propel vast amounts of plasma into space. By unraveling the intricate workings of the solar wind, scientists hope to develop a deeper understanding of space weather, which has far-reaching implications for Earth and beyond.
“Winds are produced by objects throughout the universe, so understanding what drives the wind from the sun has broad implications,” Drake said. “Winds from stars, for example, play a crucial role in shielding planetary systems from galactic cosmic rays, which can impact habitability.”
The newfound knowledge not only helps safeguard our communication networks from geomagnetic storms but also expands our understanding of winds throughout the universe. Stellar winds play a crucial role in protecting planetary systems from cosmic rays, thereby influencing the habitability of other worlds. Consequently, this research not only furthers our knowledge of our own solar system but also contributes to the search for extraterrestrial life.
As humanity becomes more interconnected and reliant on advanced technology, grasping the intricacies of the solar wind and its drivers becomes increasingly vital. The findings of this groundbreaking study provide a significant leap forward in our understanding of the solar wind, bringing us closer to unraveling the mysteries of our dynamic and awe-inspiring sun.