Space Weather

[Jherrith]

X-CLASS SOLAR FLARE (UPDATED) : A big and very active sunspot complex emerged over the sun's northeastern limb yesterday. It has already produced an X1-class solar flare. NASA's Solar Dynamics Observatory recorded the blast on April 17th at 03:34 UT:



A pulse of X-rays from the flare produced a strong shortwave radio blackout over southeast Asia and Australia: map. Mariners, aviators, and ham radio operators may have noticed unusual propagation effects at frequencies below 30 MHz.

[Jherrith]

GEOMAGNETIC STORM WATCH (G3-CLASS): Strong G3-class geomagnetic storms are possible during the early UT hours of March 31st when a Cannibal CME is expected to hit Earth's magnetic field. During such storms, naked-eye auroras can descend into the USA as far south as, e.g., Illinois and Oregon (geomagnetic latitude 50o). What is a "Cannibal CME"?

A CANNIBAL CME IS APPROACHING EARTH: Yesterday, March 28th, sunspot AR2975 unleashed a frenzy of solar flares--more than 17 in all. There were 11 C-class flares and 6 M-flares. At least two full-halo CMEs emerged from the chaos. Click to watch the storm clouds leaving the sun:


Above: A SOHO coronagraph movie of multiple CMEs on March 28, 2022.

The first CME in this movie was produced by an M4-class flare at 1129 UT. It departed the sun traveling 1259 km/s. The second CME was produced by an M1-class flare at 1923 UT. It departed even faster, travelng ~1700 km/s.

A NOAA computer model suggests that the second CME will overtake the first, merging into a single "Cannibal CME" before striking Earth's magnetic field around 0300 UT on March 31st. Click to view the complete model:



Cannibal CMEs are fast coronal mass ejections that sweep up slower CMEs in front of them. This NASA movie shows what happens. The mish-mash contains tangled magnetic fields and compressed plasmas that can spark strong geomagnetic storms.

If the NOAA model is correct, the density of solar wind plasma around Earth could increase 10-fold when the CME arrives, while the solar wind speed will top 700 km/s. These events would set the stage for G2- to G3-class geomagnetic storms.

[thelufias]

The day is fast approaching....and we shall see what comes of all this....many different scenarios....

[Jherrith]

MULTPLE CMEs ARE HEADING FOR EARTH: Sunspot AR2975 has been busy. Since yesterday it has exploded more than 17 times (11 C-class flares + 6 M-class). The eruptions have hurled at least two, possibly three, CMEs toward Earth. Click to watch the storm clouds emerge:


Above: A SOHO coronagraph movie of multiple CMEs on March 28, 2022.

The first CME (1254 UT) has already been modeled by NASA and NOAA. It is expected to hit Earth's magnetic field on March 31st. The second CME (2130 UT) and the potential third CME (2230 UT) are following close behind. They will likely arrive on April 1st. Their combined impact could spark G2- to G3-class geomagnetic storms.

Play the movie again. The snowy speckles at the beginning are energetic protons hitting the camera. They were accelerated toward Earth by shock waves in the leading edge of the CME. More than a day later, proton counts around Earth remain elevated

[Jherrith]

SOLAR FLARE, TSUNAMI AND RADIATION STORM (UPDATED): A lot of things just happened all at once. Sunspot AR2975 erupted on March 28th (1129 UT), producing a major M4-class solar flare. The blast propelled a 'solar tsunami' through the sun's atmosphere. You can see it rippling away from the blast site in this movie from the Solar Dynamics Observatory:



This tsunami was 'radio-active.' Its rippling leading edge beamed radio waves toward Earth. "I received a fantastic solar radio burst at 56 MHz," reports Rob Stammes who recorded the outburst at his space weather observatory in Lofoton, Norway. At about the same time, the US Air Force says they recorded both Type II and Type IV solar radio bursts.

Ironically, while the sun was turning itself into a temporary radio beacon, it simultaneously wiped out some radio transmissions on Earth. A pulse of X-rays from the flare ionized the top of the atmosphere over Africa, causing a shortwave radio blackout:



Aviators, mariners, and ham radio operators in the area may have noticed fading and other unusual propagation effects at frequencies below 30 MHz.

Energetic protons accelerated by the flare+tsunami are now peppering Earth's magnetosphere, causing a minor S1-class radiation storm. Our planet's magnetic field is funneling some of these particles toward the poles where a second type of radio blackout is underway--a Polar Cap Absorption Event. Airplanes flying over these regions may find that their shortwave radios won't work during the transit: polar cap absorption map.

[Jherrith]

CME IMPACT SPARKS GEOMAGNETIC STORM: As predicted, a CME hit Earth's magnetic field today, March 13th. The impact has sparked a moderately strong G2-class geomagnetic storm. When the CME arrived, "the sky exploded," reports John Dean, who sends this picture from Nome, Alaska:



"I was out from 2:30 am until sunrise," says Dean. "The coronas (auroras that seem to fall from overhead like rain) were phenomenal."

The timing of the CME's impact was unfortunate for many aurora photographers. Europe and much of North America was daylit when the storm cloud arrived. Dark skies were positioned mainly over the Pacific Ocean and western parts of North America.

What next? Geomagnetic storms could persist through March 14th as Earth passes through the CME's wake. If so, many photographers who missed the CME's arrival may get a second chance.

[Jherrith]

AN ASTEROID JUST HIT EARTH: Discovered-photographed-destroyed. Boom-boom-boom. March 11th was an eventful day for 2022 EB5. Hungarian astronomer Krisztián Sárneczky discovered the asteroid at 19:24 UT. Italian astronomer Enrico Pettarin photographed the asteroid at 20:28 UT:



The asteroid destroyed itself at ~21:22 UT when it hit Earth's atmosphere off the coast of Iceland, disintegrating harmlessly as a bright fireball. The entire sequence of events took less than 2 hours.

The explosion was detected by Comprehensive Nuclear Test Ban Treaty Organization infrasound stations in Greenland and Norway. Combining data from the two locations, University of Western Ontario astronomer Peter Brown estimates that "the asteroid exploded with an energy close to 2 kilotons of TNT. Assuming a speed of 15 km/s, it must have been about 3 meters in diameter," he says.



Above: Recorded in Greenland, the infrasound signature of asteroid 2022 EB5 exploding.

This is only the 5th time an asteroid was discovered just before it hit Earth. The others were 2008 TC3 (Sudan), 2014 AA (Atlantic Ocean), 2018 LA (Botswana), and 2019 MO (Puerto Rico). All were small space rocks that did no damage when they broke up in our planet's atmosphere. 2022 EB5 appears to be the smallest yet, and demonstrates that humans are getting better at finding potentially dangerous asteroids before they strike.

[Jherrith]

EOMAGNETIC STORM WATCH (CATEGORY G2): A full-halo CME is heading directly for Earth. ETA: late on March 13th. Coronagraphs onboard the Solar and Heliospheric Observatory (SOHO) recorded the storm cloud leaving the sun earlier today:



Note: The bright "star" at the lower right of the sun is Jupiter.

This CME is the result of a long duration C2-class solar flare near sunspot AR2962. Normally, C-class flares are not considered to be strong. However, this one lasted nearly 12 hours, allowing it to pump plenty of energy into the CME.

Moderately-strong G2-class geomagnetic storms are possible after the CME arrives. During such storms, naked-eye auroras may appear in northern-tier US states from Maine to Washington. Power grids and satellites will experience little to no effect, however.

A new model of the CME from NASA pinpoints the arrival time around 1800 UT on March 13th. In this animation, the yellow dot is Earth:



Geomagnetic storms, if they materialize, could spill into March 14th, making this a Pi Day geomagnetic storm. That's appropriate. After all, auroras form a circle around Earth's magnetic poles.

Take another look at the NASA model. The CME hits Venus less than a day before it reaches Earth. The CME won't spark a geomagnetic storm on Venus. It can't; the planet has no internally-generated global magnetic field. Instead, the impact will erode a small amount of atmosphere from Venus' unprotected cloudtops.

Geomagnetic storms: One of the perks of living on Earth. High latitude sky watchers should be alert for auroras on March 13-14.

[Jherrith]

BE ALERT FOR ZODIACAL LIGHT: It's one of the most delicate and beautiful sights in the heavens, yet most people have never seen it. We're talking about the Zodiacal Light . "A good display is coming in just a few days," says astrophotographer Petr Horálek, who created this image to whet your appetite:



"This composite shows Zodiacal Light from both hemispheres," explains Horálek. "My friend, great TWAN photographer Juan Carlos Casado, took the northern photo from the IAC La Palma Observatory in Feb. 2020. I took the southern photo from ESO's La Silla Observatory in April 2016. Stitched together they show the entire night sky using Earth's horizon to block the bright sun."

See the pale triangles of light at the center? That is Zodiacal Light.

For centuries, astronomers puzzled over the light's origin. Now we know: Zodiacal Light comes from Mars. Giant dust storms on the Red Planet leak into space, filling the plane of the Solar System with tiny grains. We can actually see the Mars dust with the naked eye because it scatters sunlight, producing the triangular glow in Horálek's photo.



February, March and April are the best months to see Zodiacal Light because the plane of the Solar System juts over the horizon almost vertically, putting the triangle on full display. Dark skies are required. Zodiacal Light is faint and easily overwhelmed by light pollution.

"New Moon dates close to the equinox are when Zodiacal Light is best seen all around the world," says Horálek. "In the northern hemisphere, visibility is best in the evening after sunset (look west). In the southern hemisphere, visibility is best in the morning before sunrise (look east)."

The next New Moon: March 2nd. Mark your calendar and see the light!

[Jherrith]

Find no extra details on AR2921, but the equator questions is a basic yes.

The equator is 40,075 km or (24,901 mi) so times ten is pretty much spot on