SwRI-led work confirms decades-old theoretical models about solar reconnection

SAN ANTONIO — August 18, 2025 — New research led by Southwest Research Institute (SwRI) has confirmed decades-old theoretical models about magnetic reconnection, the process that releases stored magnetic energy to drive solar flares, coronal mass ejections and other space weather phenomena. The data was captured by NASA’s Parker Solar Probe (PSP), which is the only spacecraft to have flown through the Sun’s upper atmosphere.

Magnetic reconnection occurs when magnetic field lines in plasma sever and reconnect in a new configuration, releasing large amounts of stored energy. On the Sun, this energy release often results in solar activity that can affect technology on Earth, a phenomenon known as space weather. Modeling solar magnetic reconnection accurately may help predict coronal mass ejections, solar flares and other space weather events that can impact satellites, communication systems and even power grids on Earth.

“Reconnection operates at different spatial and temporal scales, in space plasmas ranging from the Sun to Earth’s magnetosphere to laboratory settings to cosmic scales,” said Dr. Ritesh Patel, a research scientist in SwRI’s Solar System Science and Exploration Division in Boulder, Colorado, and lead author of a new paper published in Nature Astronomy. “Since the late 1990s, we have been able to identify reconnection in the solar corona through imaging and spectroscopy. In-situ detection was possible in Earth's magnetosphere with the launch of missions like NASA’s Magnetospheric Multiscale (MMS) mission. Similar studies in the solar corona, however, only became possible when NASA’s Parker Solar Probe launched in 2018."

PSP’s record-breaking proximity to the Sun has enabled new opportunities for study. A Sept. 6, 2022, approach revealed a huge eruption, providing an opportunity to image and sample the plasma and magnetic field properties in detail for the first time. Using a combination of imaging and in-situ diagnostic techniques as well as complementary observations from the European Space Agency’s Solar Orbiter, the SwRI-led team confirmed that PSP had flown through a reconnection region in the solar atmosphere for the very first time.

“We’ve been developing the theory of magnetic reconnection for almost 70 years, so we had a basic idea of how different parameters would behave,” Patel said. “The measurements and observations received from the encounter have validated numerical simulation models that have existed for decades within some degree of uncertainty. The data will serve as strong constraints for future models and provide a path to understand PSP’s solar measurements from other timeframes and events.”

NASA’s MMS mission, led by SwRI, provided researchers with an idea of how reconnection occurs in the near-Earth environment on a smaller scale. The 2022 PSP observations now provide researchers with the missing piece connecting Earth scale to solar scale reconnection. SwRI will next work to identify whether reconnection mechanisms accompanied with turbulence or fluctuations and waves of the magnetic fields are present in the solar regions PSP identified as having active reconnection.

“Ongoing work provides discoveries at different scales, which allows us to see how energy is transferred and how particles are accelerated,” Patel said. “Understanding these processes at the Sun can help better predict solar activity and improve our understanding of the near-Earth environment.”

The Parker Solar Probe was developed as part of NASA’s Living with a Star program to explore aspects of the Sun-Earth system that directly affect life and society. The Living with a Star program is managed by the agency’s Goddard Space Flight Center in Greenbelt, Maryland, for NASA’s Science Mission Directorate in Washington. Johns Hopkins University Applied Physics Laboratory designed, built and currently operates the spacecraft and manages the mission for NASA.

To read the Nature Astronomy paper online, visit: www.nature.com/articles/s41550-025-02623-6 or DOI: 10.1038/s41550-025-02623-6.

For more information, visit https://www.swri.org/markets/earth-space/space-research-technology/space-science/heliophysics.