It’s one of the greatest and longest-running mysteries surrounding, quite literally, our sun—why is its outer atmosphere hotter than its fiery surface?
University of Michigan researchers believe they have the answer, and hope to prove it with help from NASA’s Parker Solar Probe. In roughly two years, the probe will be the first manmade craft to enter the zone surrounding the sun where heating looks fundamentally different than what has previously been seen in space. This will allow them to test their theory that the heating is due to small magnetic waves travelling back and forth within the zone.
Solving the riddle would allow scientists to better understand and predict solar weather, which can pose serious threats to Earth’s power grid. And step one is determining where the heating of the sun’s outer atmosphere begins and ends—a puzzle with no shortage of theories.
Once within this zone, Parker Solar Probe will help determine what is causing the heating by directly measuring the magnetic fields and particles there.
“Whatever the physics is behind this superheating, it’s a puzzle that has been staring us in the eye for 500 years,” said Justin Kasper, a U-M professor of climate and space sciences and a principal investigator for the Parker mission. “In just two more years Parker Solar Probe will finally reveal the answer.”
Kasper is the principal investigator of the Solar Wind Electrons Alphas and Protons (SWEAP) Investigation on the Parker Solar Probe. SWEAP’s sensors, designed and fabricated at UC Berkeley’s Space Sciences Lab, scoop up the solar wind and coronal particles during each encounter to measure velocity, temperature, and density and shed light on the heating mystery.