Astronomers have discovered mysterious structures on the sun that produce weird plasma rain.
And this discovery may shed light on one of the greatest mysteries surrounding the sun, why our star’s surface is much cooler than its outer atmosphere, the Sun’s corona.
Now, astronomers have come up with a new explanation; and the answer is hidden inside a strange solar phenomenon that has never been observed before: plasma raining within newly found magnetic structures called Raining Null Point Topologies.
This unexpected rain has linked two long-standing solar mysteries.
How It Rains on the Sun
Observed through the high-resolution telescopes mounted on NASA’s SDO spacecraft, the Sun – a hot ball of plasma, teeming with magnetic field lines traced by giant, fiery loops — seems to have few physical similarities with Earth.
On Earth when the temperature is hot, water evaporates and turns into steam. The steam then travels into our planet’s atmosphere before it cools down reversing the process, causing water molecules to condense inside the clouds, eventually resulting in the rain that falls onto the Earth.
Now, astronomers say there’s a similar event on the sun known as coronal rain. On the sun, superheated plasma raises above the sun during solar event flares, traveling alongside invisible magnetic tracks. The plasma is cooled as it moves away from the surface of the sun, forming a fiery rainfall ar which condenses and falls back into the photosphere along the very same invisible magnetic tracks.
This means that just as the Earth, our sun also experiences rain, just made of different kinds of and coo downs.
The new research expands our knowledge on coronal rain. While previously we knew it existed, we did not know where it occurred.
The new study, published in The Astrophysical Journal Letters reveals the coronal rain occurs in a totally unexpected place and is greatly associate with a relatively new phenomenon.
physicist Emily Mason from the Catholic University of America investigated coronal rain within massive magnetic structures called helmet streamers, which can stretch out more than a million miles from the surface of the Sun before falling back around.
Mason used data from NASA’s Solar Dynamics Observatory (SDO) to look for plasma rain inside these massive solar arcs. But she couldn’t see any.
However, she did observe much smaller lops originating closer to the photosphere of the sun, that seemed to show evidence of plasma rain.
“They were really bright and they kept drawing my eye,” Mason explained in a NASA statement.
“When I finally took a look at them, sure enough, they had tens of hours of rain at a time.”
But not until Mason shared her discovery with her colleagues from NASA did scientists find out that the smaller magnetic structures —Raining Null Point Topologies (RNPTs)— were actually identified a new solar phenomenon.
“I said, ‘Wait…hold on. Where do you see it?’,” NASA solar scientist Nicholeen Viall explains. “‘I don’t think anybody’s ever seen that before!'”
RNPTs are found to take place at altitudes of up to around 50,000 kilometers (30,000 miles) above the surface of the sun.
The RNPTs are tiny compared to the helmet streamers MAson was initially observing. This small site could help astronomer explain a few things about the massive heat the Sun’s corona holds.
“These loops were much smaller than what we were looking for,” revealed NASA solar physicist Spiro Antiochos. “So that tells you that the heating of the corona is much more localized than we were thinking.”
“The ease with which these structures were identified and the frequency of rain during all observations provide compelling support for the conclusion that this is a ubiquitous phenomenon,” the authors explain in their paper.
“In all cases, the rain continues for days on what appear to be the same magnetic loops, so it is clearly not a one-shot phenomenon like flare cooling.”