Scientists uncover new clues about origins of solar wind

 

Video Credit: NASA/SDO/GOES-R

Researchers, using NASA's Parker Solar Probe, have discovered new clues about the origins of the solar wind - a continuous flow of charged particles released from the Sun that fills the solar system. This discovery is aiding scientists in their efforts to solve the 60-year-old puzzle of what heats and propels the solar wind.

Data from both space and ground-based telescopes reveal that the solar wind may be largely powered by tiny jets, known as "jetlets," at the bottom of the corona - the Sun's outer atmosphere.

The solar wind, composed of electrons, protons, and heavier ions, travels through the solar system at an approximate speed of 1 million miles per hour. When it interacts with Earth's magnetic field, it can produce beautiful auroras and interfere with GPS and communication systems. Additionally, the solar wind, as well as stellar winds in other solar systems, can alter the composition and development of planetary atmospheres, even influencing the potential for habitation on planets.

Jetlets, first observed more than 10 years ago, are the result of a process called magnetic reconnection. This happens when magnetic field lines become twisted and then suddenly realign. Magnetic reconnection is a common occurrence in plasmas, which are charged gases, and can be found in many places in the universe, from the Sun to near-Earth space to around black holes.

Scientists mainly relied on observations from the Solar Dynamics Observatory (SDO) and the Geostationary Operational Environmental Satellite-R Series’ Solar Ultraviolet Imager (GOES-R/SUVI) instrument to investigate the jetlets and magnetic fields, as well as high-resolution magnetic field data from the Goode Solar Telescope at the Big Bear Solar Observatory in California.

The findings indicated that jetlets are present in the lower solar atmosphere all over the Sun, which makes them a viable source of the steady solar wind, rather than other phenomena that vary with the 11-year cycle of solar activity, such as solar flares and coronal mass ejections.

The scientists determined that the energy and mass generated by the jetlets could account for the majority, if not all, of the energy and mass observed in the solar wind.

"The findings make it much easier to explain how the solar wind is accelerated and heated. We're not finished with the puzzle yet, but this is a major step forward for understanding a central mystery of solar physics," said Craig DeForest, a solar physicist at the Southwest Research Institute in Boulder, Colorado, and coauthor on the new paper.