Aug. 31, 2022: A CME billowed away from the farside of the sun yesterday, Aug. 30th, and it was spectacular. Coronagraphs onboard the Solar and Heliospheric Observatory (SOHO) recorded a full halo storm cloud:
If Earth were in the crosshairs, we would be bracing for a strong geomagnetic storm. Instead, Venus will absorb the blow. NASA models show the CME making a direct hit on the second planet.
The Venus impact on Sept. 1st (~0600 UT) will not cause a geomagnetic storm. It can’t. Venus has no internally-generated global magnetic field. Rather, the impact will erode some atmosphere from Venus’s unprotected cloudtops–a process that does not occur on Earth.
The source of the CME is probably active sunspot AR3088, which left the Earthside of the sun two days ago. This sunspot was extremely active while we could see it from Earth. Now Venus is in the line of fire.
Coincidentally, the European Space Agency’s Solar Orbiter spacecraft is currently very close to Venus. That means it can study the CME as it passes by. If explosions from AR3088 continue apace, Solar Orbiter could get great data in the next week as potentially many storm clouds wash over the spacecraft.
Aug. 30, 2022: It seemed like sunspot AR3088 would never stop exploding. Over the past four days, the strangely-magnetized active region produced more than a dozen M-class solar flares:
Each X-ray peak in the graph above produced a corresponding shortwave radio blackout on Earth. No part of our planet was untouched.
More than half of the explosions also produced a coronal mass ejection (CME). Earth dodged them all. Only one and maybe two delivered glancing blows of no consequence. All the rest sailed harmlessly into space.
The simple reason why: AR3088 was never facing Earth. Most of the explosions occured while the sunspot was approaching or even rounding the sun’s western limb.
This movie from NASA’s Solar Dynamics Observatory is a good example. It shows a flare from AR3088 on Aug. 29th partially eclipsed by the edge of the sun. The explosion registered M9 on GOES satellite X-ray sensors, but the uneclipsed flare was probably much stronger–perhaps even an X-flare.
If the sunspot had been facing us, we might now be experiencing strong geomagnetic storms with spectacular low-latitude auroras. Maybe next time…
Aug. 28, 2022: We’re about to find out if NASA still has the right stuff. On Monday morning, Aug. 29th at 8:33 am EDT, the most powerful rocket ever built will blast off from Kennedy Space Center’s launch pad 39B. Destination: the Moon. This is the beginning of NASA’s Artemis program, named after the twin sister of Apollo.
Artemis I will not carry any astronauts. It’s a test flight. In fact, it’s the only test flight, a controversial decision that worries some experts. Astronauts will ride the next rocket, Artemis II, in 2024. NASA will have two years to fix any problems uncovered by Artemis I.
Propelled by a 32-story tall rocket with 8.8 million pounds of thrust, Artemis I will exit Earth’s atmosphere in only 2 minutes. Less than 2 hours after that, the unoccupied Orion crew capsule will be burning straight for the Moon.
Over the course of the 42 day mission, Orion will orbit the Moon for more than a week (approaching the lunar surface within 62 miles) and travel 40,000 miles beyond the far side of the Moon before turning back to Earth.
The capsule will stay in space longer than any human spacecraft has without docking to a space station and return home faster and hotter than ever before. Indeed, a key goal of the mission is to test Orion’s heat shield when it slams into Earth’s atmosphere at 25,000 mph and heats up to 5,000 degrees Fahrenheit.
If all goes well, future launches will carry crew. Astronauts will orbit the Moon in 2024 (Artemis II), then touch down near the Moon’s south pole in 2025 (Artemis III). The moonwalkers will include the first woman to step onto the lunar surface.
Aug. 25, 2022: New sunspot AR3088 is emerging in the sun’s southern hemisphere. Its magnetic field is not normal:
Shown above is a map of magnetic fields on the sun. AR3088 is inset. According to Hale’s Law, the sunspot’s magnetic poles should be arranged +/-, that is, positive (+) on the left and negative (-) on the right. Instead, they are rotated 90 degrees; positive (+) is on top and negative (-) is on the bottom.
This is a rare “perpendicular sunspot,” with magnetic poles orthogonal to the sun’s equator. What’s going on? Something unusual may be happening to the sun’s magnetic dynamo beneath the surface where this sunspot is growing. We’ll keep an eye on AR3088 to see what happens next. Solar flare alerts: SMS Text
Aug. 23, 2022: Yesterday, NASA released the first James Webb Space Telescope (JWST) images of auroras on Jupiter. The red rings of light circling Jupiter’s poles were big enough to swallow Earth:
But Jupiter’s auroras are more then just oversized versions of our own. They are formed in a completely different way. One of the key ingredients is volcanoes, and–so much for space weather–solar activity is not required.
For the most part, Jupiter makes its own Northern and Southern Lights. It does this by spinning–like crazy. Jupiter turns on it axis once every 10 hours, dragging its giant planetary magnetic field around with it. Spinning a magnet is a great way to generate a few volts; kids do it all the time for science fair projects. Jupiter’s spin produces 10 million volts around its poles.
These voltages set the stage for non-stop auroras. The fuel comes from Jupiter’s volcanic moon Io, where active vents spew ions such as O+ and S+ into Jupiter’s magnetosphere. Polar electric fields grab these ions and slam them into Jupiter’s upper atmosphere. The resulting glow can be seen almost anytime JWST wants to look. Jupiter’s volcano-powered auroras are usually “on.”
Solar wind and CMEs can also help. However, solar storm clouds are naturally weakened by the time they travel all the way to Jupiter, five times farther from the sun than Earth. Also, Jupiter’s powerful magnetic field forms a potent shield. Io is already inside Jupiter’s “defenses,” so it can be more effective.
Two distinct auroras coexist over the poles of Jupiter: Ultraviolet auroras created by atmospheric hydrogen in its molecular form (H2) and infrared auroras created by the hydrogen ion H3+. JWST saw the infrared variety. In fact, the telescope is well instrumented to monitor these auroras. Its Near-Infrared Camera (NIRCam) has a filter that nicely captures the 3.3 to 3.6 micron glow of H3+.
Aug. 14, 2022: The sun just hurled a plume of cool, dark plasma into space following an explosion around sunspot AR3076. NASA’s Solar Dynamics Observatory recorded the blast on August 14th:
Traveling faster than 600 km/s (1.3 million mph), the plume tore through the sun’s outer atmosphere, creating a coronal mass ejection (CME). Coronagraph images from the Solar and Heliospheric Observatory (SOHO) confirm that the CME has an Earth-directed component. It could sideswipe Earth’s magnetic field on Aug. 18th, producing minor to moderate geomagnetic storms.
REVERSED POLARITY SUNSPOT: The sunspot that produced the dark plasma explosion is a little unusual. It has its signs backwards.
According to Hale’s Law, Solar Cycle 25 sunspots in the sun’s northern hemisphere should have a -/+ polarity; negative on the left, positive on the right. However, the magnetogram above shows the opposite. AR3076 is a reversed polarity sunspot.
Studies show that about 3% of all sunspots violate Hale’s Law. In many ways, reversed polarity sunspots are just like other sunspots. For instance, they have the same lifespan and tend to be about the same size as normal sunspots. In one key way they are different: According to a 1982 survey by Frances Tang of the Big Bear Solar Observatory, reversed polarity sunspots are more than twice as likely to develop complex magnetic fields mixing + and – together. Reversed polarity sunspots are therefore more likely to explode.
August 12, 2022: You’ve heard of a CME, a “coronal mass ejection.” They happen all the time. A piece of the sun’s tenuous outer atmosphere (corona) blows off and sometimes hits Earth. Something far more terrible has happened to Betegeuse. The red giant star produced an SME, or “surface mass ejection.”
Astronomers believe that in 2019 a colossal piece of Betelgeuse’s surface blew off the star. The mass of the SME was 400 billion times greater than a CME or several times the mass of Earth’s Moon. Data from multiple telescopes, especially Hubble, suggest that a convective plume more than a million miles across bubbled up from deep inside the star, producing shocks and pulsations that blasted a chunk off the surface.
“We’ve never before seen such a huge mass ejection from the surface of a star,” says Andrea Dupree of the Harvard-Smithsonian Center for Astrophysics, who is leading the study. “Something is going on that we don’t completely understand.”
After it left the star, the SME cooled, forming a dark cloud that famously dimmed Betelgeuse in 2019 and 2020. Even casual sky watchers could look up and see the change. Some astronomers worried that the dimming foreshadowed a supernova explosion. The realization that an SME is responsible has at least temporarily calmed those fears.
Betelgeuse’s brightness has since returned to normal, but something strange is still going on. Astronomers have long known that Betelgeuse is a variable star with a 430-day period. Its metronome-like change in brightness has been observed for more than 200 years. As Betelgeuse recovers, however, those pulsations are no longer regular: See the data. Spectra taken by Hubble and the Tillinghast telescope in Arizona imply that years later the surface of Betelgeuse is still bouncing like a plate of gelatin dessert–a testament to the ferocity of the blowout.
Betelgeuse is so large that if it replaced the sun at the center of our solar system, its atmosphere would extend past Jupiter. Dupree used Hubble to resolve hot spots on the star’s surface in 1996. This was the first direct image of a star other than the sun.
What’s happening now “is a totally new phenomenon that we can observe directly and resolve surface details with Hubble,” says Dupree. “We’re watching stellar evolution in real time.”
August 10, 2022: If you want to detect an earthquake on Venus–good luck. The planet’s surface is hot enough to melt lead, and the atmospheric pressure is crushing. No ground-based seismometer could possibly survive.
What’s an extraterrestrial seismologist to do? Launch a balloon.
A new paper just published in the Geophysical Research Letters reports the detection of a magnitude 7.3 earthquake by a fleet of balloons floating through the stratosphere above Indonesia’s Flores Sea. Onboard infrasound sensors registered acoustic waves rippling upward from the sea surface below, proving that, here on Earth, balloons can be used as seismometers.
“The same technique should work in the atmosphere of Venus,” says Raphael Garcia, the study’s lead author and a planetary scientist at the Institut Supérieur de l’Aéronatique et de l’Espace of the University of Toulouse. “Balloon-based sensors could float high above Venus’s deadly surface, collecting data at a safe distance.”
In the fall of 2021, the Centre National d’Etudes Spatiales (CNES) launched a fleet of 16 balloons from Mahé Island in the Seychelles archipelago. Unlike ordinary weather balloons, which explode in a matter of hours, these were “superpressure balloons,” which can remain aloft for months. Stratospheric winds carried them over the Flores Sea just in time for the temblor.
Four balloons picked up the undersea quake on Dec. 14, 2021. Combining their signals, researchers pinpointed the epicenter within 300 km, the magnitude of the quake within 0.8 units, and its onset within 50 seconds. Furthermore, waveforms recorded by the infrasound sensors were detailed enough to sense structures in the Earth 100 km deep.
Garcia would like to do the same thing on Venus. “We know nothing of its interior,” he says. “We don’t know how it’s made inside, and seismology is one of the best tools to figure that out.”
Seismic balloons could come in handy on our own planet, too. “Balloons could be used to cover ocean regions where conventional seismometers are not yet deployed,” notes Garcia. “Another advantage: Balloons may be rapidly deployed just after a big quake for monitoring aftershocks.”
The test flights have already unearthed a curiosity in South America. On Nov. 28, 2021, just one of the balloons detected a magnitude 7.5 earthquake in northern Peru. The infrasound frequency, 0.23 Hz, was higher than expected; for comparison, the Flores Sea quake registered a more typical 0.085–0.125 Hz. Garcia’s team believes the high pitch may have been caused by a “ringing” of sediments in the Amazonian basin.
Sensing earthquakes from the stratosphere is relatively new. Researchers at Caltech and the Jet Propulsion Laboratory did it for the first time in July 2019. Garcia’s study marks the first time an earthquake was detected by more than one balloon. It won’t be the last.
Aug. 8, 2022: A solar wind stream hit Earth’s magnetic field on August 7th. At first, the stream’s velocity was low, but during the day it sped up to more than 600 km/s, ultimately triggering a G2-class (moderately strong) geomagnetic storm. This event was not in the forecast, so the resulting auroras came as a surprise.
“I was already in bed getting ready for sleep when the storm began,” says Ruslan Merzlyakov. “Rushing to the beach in Nykøbing Mors, I was able to photograph the first summer auroras in Denmark in 5 years.”
“Seeing the lights dance on a warm summer night was a great experience!” he says.
In North American, auroras spilled across the Canadian border as far south as Pennsylvannia. In Wayne County, PA, Sujay Singh photographed both red auroras and STEVE. Auroras were also sighted in Montana and the Dakotas.
The solar wind stream that sparked this display is a bit of a puzzle. It might be the early arrival of a stream originally expected on Aug. 9th, flowing from an equatorial hole in the sun’s atmosphere. Or, perhaps, a CME was involved. A discontinuity in solar wind data at 0045 UT on Aug. 7th hints at a shock wave embedded in the solar wind. These days, the active sun is producing so many minor explosions, it is easy to overlook faint CMEs heading for Earth.
“Earth’s magnetic field is still reverberating on August 8th,” reports Stuart Green, who recorded the event using a backyard magnetometer in the UK:
Despite the surprise, subscribers to our Space Weather Alert Service were aware of the storm. Instant text alerts announced the arrival of the solar wind and the subsequent G2 event. Aurora alerts:SMS Text
August 4, 2022: Seeing one blue jet is rare. Photographer Matthew Griffiths just caught several of them over the Big Bend National Park in Texas. “This is by far the best,” he says:
Griffiths is an amateur photographer, primarily interested in wildlife and the Milky Way. “On July 28th, I was starting a five night West Texas road trip to capture the Milky Way,” he says. “But with thunderstorms in the distance I decided to try for red sprites instead.”
He ended up photographing the sprite’s elusive cousin, the blue jet. First recorded by cameras on the space shuttle in 1989, blue jets are part of a growing menagerie of cloudtop “transient luminous events” such as sprites, ELVES and green ghosts. They are all elusive, but blue jets may be the hardest of all to catch.
“We’re not sure why ground-based observers see them so rarely,” says Oscar van der Velde of the Lightning Research Group at the Universitat Politècnica de Catalunya. “It might have something to do with their blue color. Earth’s atmosphere naturally scatters blue light, which makes them harder to see. Blue jets might be more common than we think.”
A rookie mistake might have helped Griffiths. “This is only my second time trying for sprites. I might have aimed my camera too close to the cloud tops where bright lightning washed out the sprites; in fact, I couldn’t find any sprites in my photos. But I think my camera angle was just right for catching the bright blue jet.”
Blue jets might look like lightning, but they are not the same. Normal lightning carves a scorching-hot path through the atmosphere, heating the air to 30,000 degrees Celsius. Blue jets are made of cold plasma akin to gas inside a fluorescent light bulb. You could touch one with your hand and it might not hurt.
And, of course, they go up instead of down. Photos taken from the International Space Station (ISS) show that blue jets reach astonishing altitudes, as high as 170,000 feet. This is high enough to touch the ionosphere, possibly forming a new and poorly understood branch of Earth’s global electrical circuit.
“Also,” says van der Velde, “there can be considerable production of NOx and ozone by these discharges, potentially affecting the chemistry of the upper atmosphere.”
Clearly, it is important to study blue jets. Photographers, now you know where to look.