NASA’s Parker Solar Probe Spies Solar Wind ‘U-Turn’
Images captured by NASA’s Parker Solar Probe as the spacecraft made its record approach to the Sun in December 2024 have now revealed new details about how the solar magnetic fields responsible for space weather escape from the Sun — and how sometimes they don’t.
Like a toddler, our Sun sometimes has disruptive outbursts. But instead of causing a crisis, the Sun spews out magnetized materials and dangerous, high-energy particles that determine space weather as they travel through the solar system. These explosions can impact our daily lives, from disrupting technologies like GPS to triggering power outages, and they can also endanger traveling astronauts and spacecraft. Understanding how these solar flares, called coronal mass ejections (CMEs), occur and where they go is essential for predicting and preparing for their impacts on Earth, the Moon and Mars.
Images taken by Parker Solar Probe in December 2024, and published Thursday in the Astrophysical journal lettersrevealed that not all magnetic material in a CME escapes from the Sun – some returns, changing the shape of the solar atmosphere in subtle, but significant, ways that may determine the course of the CME’s next explosion from the Sun. These findings have far-reaching implications for understanding how the release of magnetic fields caused by the CME affects not only the planets, but also the Sun itself.
“These breathtaking images are among the closest ever taken of the Sun, and they expand what we know about our nearest star,” said Joe Westlake, director of the Heliophysics Division at NASA Headquarters in Washington. “The information we gain from these images plays an important role in understanding and predicting the evolution of space weather in the Solar System, particularly for planning missions that ensure the safety of our Artemis astronauts traveling beyond the protective shield of our atmosphere.”
As Parker Solar Probe scanned the Sun’s atmosphere on December 24, 2024, just 3.8 million kilometers from the solar surface, its Wide Field Solar Probe Imager, or WISPR, observed a CME flare from the Sun. In the wake of the CME, elongated blobs of solar material were seen falling toward the Sun.
This type of feature, called an “influx,” has already been observed remotely by other NASA missions, including SOHO (Solar and Heliospheric Observatory, a joint mission with ESA, the European Space Agency) and STEREO (Solar Terrestrial Relations Observatory). But Parker Solar Probe’s very close view from the solar atmosphere reveals details of matter falling toward the Sun and on scales never seen before.
“We’ve already seen hints that material can fall back toward the Sun in this way, but to see it with this clarity is incredible,” said Nour Rawafi, Parker Solar Probe project scientist at the Johns Hopkins Applied Physics Laboratory, who designed, built and operates the spacecraft in Laurel, Maryland. “This is a truly fascinating and revealing insight into how the Sun continually recycles its magnetic fields and coronal materials.”
For the first time, Parker Solar Probe’s high-resolution images allowed scientists to take precise measurements of the inflow process, such as the speed and size of droplets of material drawn toward the Sun. These previously hidden details offer scientists new insights into the physical mechanisms that reconfigure the solar atmosphere.
