Posted on 06/06/2019 12:08:09 AM PDT by SunkenCiv
...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...
Such high temperatures cause the solar atmosphere to swell to many times the diameter of the sun and they're the reason we see the extended corona during solar eclipses. In that sense, Kasper says, the coronal heating mystery has been visible to astronomers for more than half a millenium, even if the high temperatures were only appreciated within the last century.
This same zone features hydromagnetic "Alfvén waves" moving back and forth between its outermost edge and the sun's surface. At the outermost edge, called the Alfvén point, the solar wind moves faster than the Alfvén speed, and the waves can no longer travel back to the sun...
In trying to estimate how far from the sun's surface this preferential heating stops, U-M's team examined decades of observations of the solar wind by NASA's Wind spacecraft. They looked at how much of helium's increased temperature close to the sun was washed out by collisions between ions in the solar wind as they traveled out to Earth...
Those calculations put the outer edge of the superheating zone roughly 10 to 50 solar radii from the surface. It was impossible to be more definitive since some values could only be guessed at.
(Excerpt) Read more at phys.org ...
As long as we agree that “heat” is the measurement of the movement of atoms and molecules, then we both probably agree that “density” matters.
For instance, if the temperature of the Earth's atmosphere was 1 million degrees, the Earth's surface would vaporize in a couple of minutes.
However, if the density of the Earth's 1 million degree atmosphere was reduced by 99.99%, it would probably take centuries for vaporization to occur, or maybe even never.
“Super-heating” in the corona is a really interesting puzzle, but I think most people imagine the corona in terms of the density of the Earth's atmosphere, which is not correct.
Since it’s orbiting the sun does it have a rear facing camera so it can scan for Nibiru?
Putting a probe on a longer-period object has actually been suggested for outer solar system exploration. Trick is, catching the object with chemical propulsion...
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