Solar ‘tadpole-like’ jets seen with NASA’S IRIS add new clue to age-old mystery


Scientists have discovered tadpole-shaped jets coming out of regions with intense magnetic fields on the Sun. Unlike those living on Earth, these “tadpoles” — formally called pseudo-shocks — are made entirely of plasma, the electrically conducting material made of charged particles that account for an estimated 99 percent of the observable universe. The discovery adds a new clue to one of the longest-standing mysteries in astrophysics.

mages from IRIS show the tadpole-shaped jets containing pseudo-shocks streaking out from the Sun. 
CREDIT Abhishek Srivastava IIT (BHU)/Joy Ng, NASA’s Goddard Space Flight Center

View animated GIF:

For 150 years scientists have been trying to figure out why the wispy upper atmosphere of the Sun — the corona — is over 200 times hotter than the solar surface. This region, which extends millions of miles, somehow becomes superheated and continually releases highly charged particles, which race across the solar system at supersonic speeds.

When those particles encounter Earth, they have the potential to harm satellites and astronauts, disrupt telecommunications, and even interfere with power grids during particularly strong events. Understanding how the corona gets so hot can ultimately help us understand the fundamental physics behind what drives these disruptions.

In recent years, scientists have largely debated two possible explanations for coronal heating: nanoflares and electromagnetic waves. The nanoflare theory proposes bomb-like explosions, which release energy into the solar atmosphere. Siblings to the larger solar flares, they are expected to occur when magnetic field lines explosively reconnect, releasing a surge of hot, charged particles. An alternative theory suggests a type of electromagnetic wave called Alfvén waves might push charged particles into the atmosphere like an ocean wave pushing a surfer. Scientists now think the corona may be heated by a combination of phenomenon like these, instead of a single one alone.

The new discovery of pseudo-shocks adds another player to that debate. Particularly, it may contribute heat to the corona during specific times, namely when the Sun is active, such as during solar maximums — the most active part of the Sun’s 11-year cycle marked by an increase in sunspots, solar flares and coronal mass ejections.

The discovery of the solar tadpoles was somewhat fortuitous. When recently analyzing data from NASA’s Interface Region Imaging Spectrograph, or IRIS, scientists noticed unique elongated jets emerging from sunspots ¬– cool, magnetically-active regions on the Sun’s surface — and rising 3,000 miles up into the inner corona. The jets, with bulky heads and rarefied tails, looked to the scientists like tadpoles swimming up through the Sun’s layers.

“We were looking for waves and plasma ejecta, but instead, we noticed these dynamical pseudo-shocks, like disconnected plasma jets, that are not like real shocks but highly energetic to fulfill Sun’s radiative losses,” said Abhishek Srivastava, scientist at the Indian Institute of Technology (BHU) in Varanasi, India, and lead author on the new paper in Nature Astronomy.

Using computer simulations matching the events, they determined these pseudo-shocks could carry enough energy and plasma to heat the inner corona.

The scientists believe the pseudo-shocks are ejected by magnetic reconnection — an explosive tangling of magnetic field lines, which often occurs in and around sunspots. The pseudo-shocks have only been observed around the rims of sunspots so far, but scientists expect they’ll be found in other highly magnetized regions as well.

Over the past five years, IRIS has kept an eye on the Sun in its 10,000-plus orbits around Earth. It’s one of several in NASA’s Sun-staring fleet that have continually observed the Sun over the past two decades. Together, they are working to resolve the debate over coronal heating and solve other mysteries the Sun keeps.

The tadpole-shaped pseudo-shocks, shown in dashed white box, are ejected from highly magnetized regions on the solar surface. CREDIT Abhishek Srivastava IIT (BHU)/Joy Ng, NASA’s Goddard Space Flight Center

“From the beginning, the IRIS science investigation has focused on combining high-resolution observations of the solar atmosphere with numerical simulations that capture essential physical processes,” said Bart De Pontieu research scientist at Lockheed Martin Solar & Astrophysics Laboratory in Palo Alto, California. “This paper is a nice illustration of how such a coordinated approach can lead to new physical insights into what drives the dynamics of the solar atmosphere.”

The newest member in NASA’s heliophysics fleet, Parker Solar Probe, may be able to provide some additional clues to the coronal heating mystery. Launched in 2018, the spacecraft flies through the solar corona to trace how energy and heat move through the region and to explore what accelerates the solar wind as well as solar energetic particles. Looking at phenomena far above the region where pseudo-shocks are found, Parker Solar Probe’s investigation hopes to shed light on other heating mechanisms, like nanoflares and electromagnetic waves. This work will complement the research conducted with IRIS.

“This new heating mechanism could be compared to the investigations that Parker Solar Probe will be doing,” said Aleida Higginson, deputy project scientist for Parker Solar Probe at Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. “Together they could provide a comprehensive picture of coronal heating.”


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February 20, 2019 1:59 am

I dips me pseudo lid to them mighty tough tadpoles.

February 20, 2019 2:06 am

Think! What is the origin of a magnetic field? What is seen is the interplay of strong currents. If there are currents then there are electric fields proiding the heating in the corona.

Johann Wundersamer
Reply to  Lars Silen
February 20, 2019 3:25 am


Patrick MJD
February 20, 2019 2:07 am

“Over the past five years, IRIS has kept an eye on the Sun in its 10,000-plus orbits around Earth.”

The sun was in line-of-sight all the time?

Reply to  Patrick MJD
February 20, 2019 2:42 am

Theoretically possible.
The satellite orbits above the terminator, the line which separates day from night. Then the sun is visible non-stop. Not sure it is strictly required, though.

Rich Davis
Reply to  Patrick MJD
February 20, 2019 3:07 am

Mama always told me not to look into the eyes of the sun. But mama! That’s where the fun is!

Leo Smith
February 20, 2019 2:15 am

For 150 years scientists have been trying to figure out why the wispy upper atmosphere of the Sun — the corona — is over 200 times hotter than the solar surface. This region, which extends millions of miles, somehow becomes superheated and continually releases highly charged particles, which race across the solar system at supersonic speeds.

Its obviously downwelling radiation from a layer of CO2….

February 20, 2019 2:56 am

Those are the little swimmers that fertilize Gaia.

Gaia theory is confirmed by Nasa.

Rich Davis
February 20, 2019 2:59 am

Watch out for the solar frogs that will be leaping out of the corona in a few weeks if they’re seeing tadpoles now.

February 20, 2019 3:09 am

Anthony were you hoping for some more intelligent commentary?

Reply to  Warren
February 20, 2019 9:02 am

Not from you.

February 20, 2019 4:12 am

I wonder if it is related to Solar Corona Rain?

It actually rains on the Sun!

And as we know all rain needs an aerosol (plasma-sol ?) nucleation, is Solar plasma rain affected by GCR intensity – a kind of catalysis ?

Luther Bl't
Reply to  bonbon
February 20, 2019 9:36 am

Logical. Without rain the tadpoles would dry up and perish.

Reply to  bonbon
February 20, 2019 2:19 pm

could this super heated water explode and leave a sun spot and cause a mass ejection ???

Reply to  jmorpuss
February 20, 2019 10:49 pm

When you where a kid , did you ever squirt water on red hot coals and see the dark spot it left for a while? It looked like a sun spot. There’s plenty of hydrogen ejected from the sun, all you need is oxygen and bingo H2O water-vapour. This all takes place while the sun is in the middle of a 11 year cyclic pole flip. If the sun has a Bow Shock or a Bow Wave, it means it’s travelling through something that puts up a resistance. All the planets in our solar system are sucked along in the tail of the sun as it’s sucked along around the galaxy we call the milky way.
“The two Voyager spacecraft have explored the outer reaches of the heliosphere, passing through the termination shock and the heliosheath. NASA announced in 2013 that Voyager 1 had encountered the heliopause on August 25, 2012, when the spacecraft measured a sudden increase in plasma density of about forty times.[2] In 2018, NASA announced that Voyager 2 had traversed the heliopause on November 5 of that year.[3] Because the heliopause marks the boundary between matter originating from the Sun and matter originating from the rest of the galaxy, spacecraft such as the two Voyagers, which have departed the heliosphere, can be said to have reached interstellar space. ”

Peter C.
February 20, 2019 4:24 am

Sigh the sun is electric .

Reply to  Peter C.
February 20, 2019 6:05 pm

So is a thunder storm in part, but a thunderstorm is much more than electrical phenomena. Even a nuclear explosion is partly an electric phenomena but mostly the electrical aspects emerge as effects of matter v matter, and matter v photon interaction. So do we then conclude the universe is wholly electric? Or is it just that matter in its dynamic process of interactions innately generates electrical phenomena as a result of releasing charged matter particles?

Reply to  WXcycles
February 20, 2019 6:07 pm

Neutrons and photons have no charge, and both are significant particles in our universe.

Reply to  Keith Sketchley
February 21, 2019 6:46 am

So no ‘electric universe’ then?

February 20, 2019 4:52 am

(Take the following with a grain of salt.)

Okay, I get it.

The tadpoles swim around, creating a current, which generates electricity. That makes the Sun electric. So if the Sun is electric, isn’t putting up solar panels to generate electricity on Earth stealing electricity from the Sun? They absorb solar energy, don’t they? And solar energy is electricity, so if you steal electricity from the Sun, it will go out, won’t it? /s

Try that argument on some Greenies and see if they can sort it out. It should confuse them. If it doesn’t, I haven’t done my job.

February 20, 2019 5:09 am

An alternative theory suggests a type of electromagnetic wave called Alfvén waves
Alfvén waves are not electromagnetic waves, but a type of magnetohydrodynamic wave in which ions oscillate in response to the restoring force provided by an effective tension on the magnetic field lines. So are waves in matter.

Reply to  Leif Svalgaard
February 20, 2019 8:28 am


“So are waves in matter.”

In laboratory proven quantum theory these waves collapse into solid particles when “observed” . So, when not observed all of this is a probability distribution of potential solid matter in wave form. I guess “Someone” is always looking. I wonder Who?



Reply to  JimG1
February 20, 2019 9:28 am

In laboratory proven quantum theory these waves collapse into solid particles when “observed”
No, it is not a quantum issue. As Alfven said [1942]: “If a conducting liquid is placed in a constant magnetic field, every motion of the liquid gives rise to an E.M.F. which produces electric currents. Owing to the magnetic field, these currents give mechanical forces which change the state of motion of the liquid.” So, conducting matter [e.g. plasma, but also Mercury and other fluids] moving in a magnetic field creates electric currents whose magnetic field, producing mechanical forces which act back on the fluid, and to the initial field and thus sustains the movements of the charged [the propagating ‘wave’].

February 20, 2019 11:03 am

Before we get deluged with all kinds of “tadpole” theories, explaining how these corona-busting tadpoles somehow (watch my hands wave) control the Earth’s climate, consider this solar factoid: the Sun’s corona is astonishingly tenuous.

In fact, the Earth’s atmosphere is almost 2000 times more massive (5×10¹⁸kg) than the corona (3×10¹⁴kg). To put that in a more familiar perspective, consider that Mount Everest contains ten times more mass (3×10¹⁵kg) than the corona.

Pieces of the corona, with mass on the order of a billion kilograms, are frequently emitted as CME’s, with significant impact on our upper atmosphere and magnetosphere, with occasionally severe geomagnetic storms.

Yes, the temperature of the corona is a million degrees, but it is so tenuous that any transfer of that heat to the Earth’s troposphere would be negligible.

Now, let the Tadpole Theories proliferate. Bring them on!

John Robertson
February 20, 2019 4:32 pm

I hope to be around in ten years or so,to compare what we know then with what we think we know now.
I suspect we are about to reboot many of our solar speculations.
This is science in action,each new observation provokes new questions.

Pamela Gray
February 20, 2019 5:29 pm

Scotty: Jim! The magnetodrive repair will take at least 3 days! I cannot go any faster!
Jim: Do it in 1 day Scotty. Do it!
Spock: The magnetodrive can be repaired in 24.0957854326890 hours.

February 20, 2019 9:18 pm

Pamela Gray, What Scotty is telling Jim to fix is the electric AC drive.
“A magneto is an electrical generator that uses permanent magnets to produce periodic pulses of alternating current. Unlike a dynamo, a magneto does not contain a commutator to produce direct current. It is categorized as a form of alternator, although it is usually considered distinct from most other alternators, which use field coils rather than permanent magnets.”

February 21, 2019 2:49 am

“Scientists have discovered tadpole-shaped jets coming out of regions with intense magnetic fields on the Sun. Unlike those living on Earth, these “tadpoles”—formally called pseudo-shocks—are made entirely of plasma,”

The above quote is from
and is identical to the part of the first paragraph, I just wanted to make sure.
This kind of ‘race to the bottom’ language of popularising science by Nature/NASA in my view, not only doesn’t achieve its aim; to the contrary is demeaning to those with even the limited solar physics knowledge and creates totally wrong impressions with those that are far less informed.
I would now expect Nature/NASA to tell us something on following lines:
If you walk on the surface of the sun you would find yourself climbing up the Earth size plasma bubbles, and if you are ‘lucky’ enough, the one you are on might just shoot a CME in the Earth’s direction, you having free ride in just 2-3 days back somewhere in Canada, enjoying most spectacular aurora display ever, a bit (geomagnetic) stormy but not of a much concern.
‘tadpoles’ indeed !

February 21, 2019 4:07 am

Here we go again:
“Have you ever seen a dragon in the sky? Although real flying dragons don’t exist, a huge dragon-shaped aurora developed in the sky over Iceland earlier this month,” NASA wrote in their post.
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