Here we learn that the solar wind ‘has a sort of internal heater’, which may be short on scientific explanation but sounds interesting as far as it goes.
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There’s a wind that emanates from the sun, and it blows not like a soft whistle but like a hurricane’s scream, says Phys.org.
Made of electrons, protons, and heavier ions, the solar wind courses through the solar system at roughly 1 million miles per hour, barreling over everything in its path.
Yet through the wind’s roar, NASA’s Parker Solar Probe can hear small chirps, squeaks, and rustles that hint at the origins of this mysterious and ever-present wind.
Now, the team at the Johns Hopkins Applied Physics Laboratory, which designed, built, and manages the Parker Solar Probe for NASA, is getting their first chance to hear those sounds, too.
“We are looking at the young solar wind being born around the sun,” says Nour Raouafi, mission project scientist for the Parker Solar Probe. “And it’s completely different from what we see here near Earth.”
Scientists have studied the solar wind for more than 60 years, but they’re still puzzled over many of its behaviors.
For example, while they know it comes from the sun’s million-degree outer atmosphere called the corona, the solar wind doesn’t slow down as it leaves the sun—it speeds up, and it has a sort of internal heater that keeps it from cooling as it zips through space.
With growing concern about the solar wind’s ability to interfere with GPS satellites and disrupt power grids on Earth, it’s imperative to better understand it.
Just 17 months since the probe’s launch and after three orbits around the sun, Parker Solar Probe has not disappointed in its mission.
“We expected to make big discoveries because we’re going into uncharted territory,” Raouafi says. “What we’re actually seeing is beyond anything anybody imagined.”
Researchers suspected that plasma waves within the solar wind could be responsible for some of the wind’s odd characteristics.
Just as fluctuations in air pressure cause winds that force rolling waves on the ocean, fluctuations in electric and magnetic fields can cause waves that roll through clouds of electrons, protons, and other charged particles that make up the plasma racing away from the sun. Particles can ride these plasma waves much like the way a surfer rides an ocean wave, propelling them to higher speeds.
“Plasma waves certainly play a part in heating and accelerating the particles,” Raouafi says.
Scientists just don’t know how much of a part. That’s where Parker Solar Probe comes in.
Full article here.
via Tallbloke’s Talkshop
January 17, 2020 at 12:27PM
Iowa Climate Science Education 