Since it launched last year, NASA's Parker Solar Probe has made three dives toward the sun as it reached the fastest speed ever clocked by a human-built vehicle. Scientists released the first batch of findings, revealing that the dynamics of our star are even weirder than once imagined.
Four papers in the journal Nature describe what the spacecraft observed during its first two flybys, as it passed within about 15 million miles of the sun. "All of this brand-new information about how the way our star works is going to help us understand how the sun drives change in the space environment throughout our solar system," said Nicola Fox, director of the heliophysics division at NASA.
One puzzle that scientists have been pondering for decades: Why is the solar atmosphere superhot?
The surface of the sun is about 10,000 degrees Fahrenheit. But in the thin atmosphere known as the corona the temperatures jump by a factor of 300 or more, to millions of degrees.
Justin C. Kasper, a professor of space sciences and engineering at the University of Michigan, said scientists had a hunch that the vibrating of the sun's magnetic fields — like the plucking of a guitar string — was critical to heating the corona. As expected, the vibrations did get stronger. But the instrument also picked up "rogue waves," Kasper said.
As the probe gets closer — repeated flybys of Venus will eventually nudge it to a trajectory that will take it within 4 million miles of the sun — it is likely to reveal new mysteries. Daniel Verscharen, a space scientist, said the discoveries "show that there is a lot more happening close to the sun and that it's absolutely worth going there to explore further."
New York Times
