NASA Enters the Solar Atmosphere for the First Time

NASA Enters the Solar Atmosphere for the First Time

Kristopher Klein

Emily Lichko

Assistant Professor Kristopher Klein and Postdoctoral Research Associate Emily Lichko are co-authors on the paper describing the latest science results from the Parker Solar Probe.

On December 14, scientists confirmed that, for the first time in history, a spacecraft touched the Sun. NASA’s Parker Solar Probe flew through the Sun’s upper atmosphere—the corona—and sampled particles and magnetic fields there. As it dipped into and out of the solar corona, the probe confirmed that the outer boundary of the solar atmosphere is 8.1 million miles from the solar surface. The spacecraft also confirmed previous hypotheses that the boundary between the solar atmosphere and solar wind is not a smooth sphere but has spikes and valleys that wrinkle the surface. Discovering where these protrusions line up with solar activity coming from the surface can help scientists learn how events on the Sun affect the atmosphere and solar wind. The probe also discovered that the magnetic zig-zag structures in the solar wind, called switchbacks, originate from the solar surface (photosphere). The patches aligned with magnetic funnels that emerge from the photosphere between convection cell structures called supergranules. In addition to being the birthplace of switchbacks, the magnetic funnels might be where one component of the solar wind originates. The solar wind comes in two different varieties—fast and slow—and the funnels could be where some particles in the fast solar wind come from. Understanding where and how the components of the fast solar wind emerge, and if they’re linked to switchbacks, could help scientists answer a longstanding solar mystery: how the solar corona is heated to millions of degrees, far hotter than the solar surface below.