Significant Farside Explosion

Jan. 4, 2023: Something just exploded on the farside of the sun. SOHO watched the debris–a very bright and fast CME–billow away from the sun’s southeastern limb on Jan. 3rd:

It won’t hit Earth. NOAA analysts have modeled the CME and determined that the edge of the storm cloud will narrowly miss our planet a few days from now.

NASA’s Solar Dynamics Observatory detected shock waves from the blast wrapping around both of the sun’s poles. This suggests a very powerful explosion–possibly an X-flare. Radiation from the flare was eclipsed by the edge of the sun, reducing its intensity by one to two orders of magnitude, so that Earth-orbiting satellites detected only a C4-class event.

Whatever exploded will soon turn to face Earth. Helioseismic echoes pinpoint its location no more than 2 days behind the sun’s eastern limb:

This might be old sunspot AR3163, which spent the last two weeks transiting the farside of the sun. It was big the last time we saw it in December and may have grown even bigger since. Stay tuned! Solar flare alerts: SMS Text.

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Sunspot Counts Hit a 7-Year High

Jan. 2, 2022: December was a busy month on the sun. How busy? Senol Sanli of Bursa, Turkey, answered the question by stacking 26 days of sun photos (Dec. 2nd – 27th) from NASA’s Solar Dynamics Observatory:

“There were more than 24 sunspot groups, some of them quite large, congested in two bands on opposite sides of the sun’s equator,” says Sanli.

The congestion of dark cores catapulted the monthly sunspot number to its highest value in 7 years:

This plot from NOAA shows the ascending progression of Solar Cycle 25. It has outperformed the official forecast for 35 months in a row. If the trend continues, Solar Maximum will either happen sooner or be stronger than originally expected–possibly both. Stay tuned for lots more sunspots.

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Cosmic Rays Sink to a 6-Year Low

Dec. 30, 2022: Cosmic rays reaching Earth just hit a six-year low. Neutron counters in Oulu, Finland, registered the sudden decrease on Dec. 26th when a coronal mass ejection (CME) hit Earth’s magnetic field:

The CME swept aside galactic cosmic rays near our planet, abruptly reducing radiation levels. Researchers call this a “Forbush Decrease,” after American physicist Scott Forbush, who studied cosmic rays in the early 20th century.

The Dec. 26th event continues a trend that began in 2020. Since then, cosmic ray fluxes have been fitfully decreasing as one CME after another hit Earth. The reason is Solar Cycle 25, which began around that time and has been gaining strength. The Forbush Decreases are adding up.

Scott Forbush was the first to notice the yin-yang relationship between solar activity and cosmic rays. When one goes up, the other goes down. CMEs play a big role in this relationship. The solar storm clouds contain tangled magnetic fields that do a good job scattering cosmic rays away from our planet.

A recent paper in the Astrophysical Journal looked at the last two solar cycles and compared the daily rate of CMEs to the strength of cosmic rays near Earth. This plot shows the results:

At the peak of Solar Cycle 24, the sun was producing more than 5 CMEs per day. At the same time, galactic cosmic rays (GCRs) dropped more than 60%.

Neutron counts are now at their lowest level since 2016. If current trends continue, cosmic ray levels will plunge even further in the years ahead, perhaps even lower than Solar Cycle 24. This is good news for astronauts and polar air travelers who will benefit from less radiation.

FAQ: Why neutrons? When cosmic rays strike Earth’s atmosphere, they produce a spray of secondary particles that rain down on Earth. Among these particles are neutrons, which can make it all the way down to Earth’s surface. Researchers at the Sodankyla Geophysical Observatory in Oulu, Finland, have been counting neutrons every day since 1964, providing an unparalleled record of cosmic rays for almost 60 years.

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HAARP Pings a Near-Earth Asteroid

Dec. 26, 2022: Researchers from NASA and the University of Alaska are about to perform an unusual radar experiment. They’re going to ping a near-Earth asteroid using shortwave radio. The target is a 500-ft-wide space rock named “2010 XC15.” When it passes by Earth on Tuesday, Dec. 27th, the HAARP array in Alaska will hit it with a pulse of 9.6 MHz radio waves.

The High-frequency Active Auroral Research Program (HAARP) site in Gakona, Alaska

Radio astronomers ping asteroids all the time. What’s unusual about this experiment is the frequency: 9.6 MHz is hundreds of times lower than typical S-band and X-band frequencies used by other asteroid radars. The goal is to probe the asteroid’s interior.

Lead investigator Mark Haynes of the Jet Propulsion Laboratory (JPL) explains: “The low frequencies we are using can penetrate the asteroid, unlike S-band or X-band frequencies which reflect mostly off of the surface. Ultimately the idea is to use echoes to form tomographic images of asteroid interiors.”

Knowing the internal structure of an asteroid could come in handy — especially if you need to destroy it. 2010 XC15 poses no threat 770,000 km from Earth. Tomorrow’s experiment is proof-of-concept for a scarier object: Asteroid Apophis, which will buzz Earth closer than many satellites on April 13, 2029. If shortwave asteroid radar works for 2010 XC15, it should work for Apophis, too, giving planetary defense experts key data about the asteroid’s vulnerabilities.

Above: The OVRO Long Wavelength Array near Bishop, CA, will receive echoes from HAARP’s transmission

HAARP will transmit a continually chirping signal to asteroid 2010 XC15 at slightly above and below 9.6 MHz. The chirp will repeat at two-second intervals. The University of New Mexico Long Wavelength Array near Socorro, NM, and the Owens Valley Radio Observatory Long Wavelength Array near Bishop, CA, will receive the reflected signal.

“This will be the lowest frequency asteroid radar observation ever attempted,” notes Lance Benner, a co-investigator from JPL. If the experiment works it could mark a significant advance in asteroid radar. Stay tuned!

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A New Paradigm for Solar Activity: The Extended Solar Cycle

Dec. 12, 2022: So you thought you knew the solar cycle? Think again. A new paper published in Frontiers in Astronomy and Space Sciences confirms that there is more to solar activity than the well-known 11-year sunspot cycle. Data from Stanford University’s Wilcox Solar Observatory (WSO) reveal two solar cycles happening at the same time, and neither is 11 years long.

“We call it ‘the Extended Solar Cycle,'” says lead author Scott McIntosh of NCAR. “There are two overlapping patterns of activity on the sun, each lasting about 17 years.”

Solar physicists have long suspected this might be true. References to “overlapping solar cycles” can be found in research literature as far back as 1903.  A figure from the new Frontiers paper seems to clinch the case:

The top panel shows sunspot counts since 1976. The curve goes up and down every 11 years, which explains why everyone thinks the solar cycle is 11 years long. The bottom panel shows what’s really going on.

“The red and blue colors represent magnetic fields on the surface of the sun,” explains Phil Scherrer of Stanford University, a co-author of the paper who works closely with data from the Wilcox Solar Observatory. “We have been monitoring these fields since 1976, gathering a unique long-term record of the sun’s magnetism.”

Wilcox data show not one but two co-existing patterns of activity. They overlap in a way any music major will recognize: The sun is “singing rounds.” A round is a musical piece in which multiple voices sing the same melody, but start the song at different times. Imagine a group of children singing “Row, row, row your boat.” Half of the kids start first; the other half start 5 syllables later. The sun is doing the same thing with its magnetic fields, except instead of 5 syllables (“row, row, row your boat“) the gap is a little more than 5 years.

In the zoomed-in image, above, two representative cycles are labeled “1” and “2”. Most of the time both cycles are active, but not always. When one stops (….life is but a dream…), the other takes complete control of the sun and sunspot counts surge. This is when Solar Maximum happens. McIntosh calls the transition “the Terminator.”

11 years vs. 17 years. 1 cycle vs. 2 cycles. What difference does it make?

“The Extended Solar Cycle may be telling us something crucial about what’s happening deep inside the sun where sunspot magnetic fields are generated,” says McIntosh. “It poses significant challenges to prevalent dynamo theories of the solar cycle.”

Want to learn more? Milestone references in the development of the Extended Solar Cycle paradigm include Martin & Harvey (1979), Wilson et al (1988), Srivastava et al (2018).

Major Cryovolcanic Eruption on a Comet

Nov. 25, 2022: The British Astronomical Association (BAA) is reporting a new outburst of cryovolcanic comet 29P/Schwassmann-Wachmann. On Nov. 22nd, the comet’s nucleus suddenly brightened by more than 4 magnitudes–a sign that a major eruption was underway. Cryomagmatic debris is now expanding in a shell shaped like Pac-Man:

Cai Stoddard-Jones took the picture on Nov. 23rd using the Faulkes Telescope North in Hawaii. At the time, the shell was already more than 100,000 km in diameter.

The Pac-Man shape of the ejecta shows that this is not a uniform global eruption. Instead, it is coming from one or more discrete sources on the comet’s surface.

This fits a leading model of the comet developed by Dr. Richard Miles of the British Astronomical Association. Miles believes that 29P is festooned with ice volcanoes. There is no lava. The “magma” is a cold mixture of liquid hydrocarbons (e.g., CH4, C2H4, C2H6 and C3H8) akin to those found in lakes and streams on Saturn’s moon Titan. The comet’s cryomagma is suffused with dissolved gases N2 and CO, a bit like carbonation in a soda bottle. These bottled-up volatiles love to explode when a fissure is opened by the warming action of sunlight.

A new image taken on Nov. 25th by astronomers André Debackère and M. Malaric adds weight to the idea that a single volcano is driving the outburst. Processing the data with a rotational gradient filter, Debackère found a bright plume of debris at position angle 330 degrees (the 1 o’clock position):

This narrow plume probably leads back to the primary source the eruption. Currently streaming away from the nucleus at 75 m/s (270 km/hr), the plume stretches more than 11,000 km into space. If an eruption like this were happening on Earth, it would be plastering thousands of satellites with frosty hydrocarbons.

The integrated brightness of the comet (magnitude +11), puts it within easy reach of many backyard telescopes. Pac-Man already subtends an angle wider than Mars and, if past eruptions are any guide, it should grow much larger in the nights ahead. Observers can find 29P after sunset in the constellation Gemini.

For more information visit the British Astronomical Association’s MISSION 29P website.

more images: from Tom Gwilym of Sturgeon Bay, Wisconsin;

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A Small Asteroid Just Hit Earth. Astronomers Saw it Coming

Nov. 19, 2022: Astronomers are getting better at this. Today, for the 6th time in recent history, an Earth-bound asteroid was discovered before it hit Earth. Astronomer David Rankin was conducting a routine survey at Mt Lemmon, Arizona, on Nov. 19th when he spotted the 0.7-meter space rock coming in from the asteroid belt. Three hours later it was blazing through the atmosphere above Canada:

Dereck Bowen photographed the Moon-bright fireball (above) from his backyard in Brantford, Ontario. “It was a lucky shot,” he says. “I had my GoPro set up trying to get some action from the Leonid meteor shower, and I was astonished to find the asteroid.”

Not everyone was surprised. Rankin’s discovery triggered warnings of an imminent impact. According to the Minor Planet Center, seven observatories had time to photograph the sub-meter object before it hit on Nov. 19th at 08:27 UTC. This is a testament to astronomers’ improving ability to catch incoming dangers from space.

After the asteroid entered the atmosphere, ground-based weather radars tracked pieces of the disintegrating space rock as far down as 850 meters above Earth’s surface. It was a deep hit, and meteorites may have reached the ground east of Grimsby, Ontario. NASA created this map of the fall zone:

Above: Colored polygons estimate the landing sites of meteorites from ~1g (yellow) to 10kg (red) [more maps] Credit:NASA/ARES

Most of the fall landed in Lake Ontario but small masses might be found east of Grimsby with larger masses near McNab, according to NASA’s Astromaterials Research and Exploration Science Division. If you find a piece, here’s how to handle it.

More than 50 eyewitness reports of the fireball have been submitted to the American Meteor Society from as far south as Maryland in the USA. Experienced observers say the fireball’s peak brightness was between magnitude -10 and -20. For some people the fireball was brighter than a full Moon.

The Minor Planet Center has posthumously designated this asteroid 2022 WJ1.

For the record, previous asteroids detected just before they hit Earth are: 2008 TC3, 2014 AA, 2018 LA, 2019 MO, and 2022 EB5. There have been two this year alone!

more images: from Brian Curtis of Sault Ste Marie, Michigan

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Why Do Russian Rockets Make Blue Auroras?

Nov. 15, 2022: On Nov. 3rd, 2022, sky watchers in Sweden and Norway watched a strange blue aurora snake across the night sky. Its color and motion seemed to defy the normal laws of aurora physics. Indeed, it was not an aurora. Experts quickly realized that the display coincided with the launch of an ICBM from a Russian submarine beneath the White Sea.

It wasn’t the first time blue clouds have appeared. On Dec. 9, 2009, a Russian rocket caused a worldwide sensation when it created a blue spiral over Norway. “Blue auroras” appeared again on Oct. 26, 2017, following another Russian battle drill:


The blue exhaust of a Russian rocket on Oct. 26, 2017. Credit: Alexey Yakovlev of Strezhevoy, Russia

Over the years, Arctic sky watchers have seen many of these blue clouds, with explanations ranging from auroras to aliens to wormholes in space. In fact, rockets are the most likely explanation. Common threads seem to be the involvement of Bulava and Topol missiles, and the use of solid propellant ascent motors.

A paper published in 2016, “Exceptional optical phenomena observed during the operation of Russian launchers,” explains how such rockets might produce blue lights:

“A major combustion product of the solid fuel is aluminum oxide Al2O3 (~40% by mass),” the authors write. “At high temperatures, the formation of aluminum monoxide, AlO, also occurs. AlO exists in a gaseous state. Resonant scattering of sunlight by these molecules causes the luminescence in the wavelength region 4374–5424 Ǻ, which corresponds to the turquoise color of the gas-dust trail of the rocket.”

Mystery solved? Probably. But that doesn’t mean we don’t want to investigate further. Arctic sky watchers, if you see any future “blue auroras,” submit your photos here.

Mysterious Blue Auroras

Nov. 3, 2022: Thursday night (Nov. 3rd) in Sweden, sky watchers were puzzled when a strange ribbon of blue light appeared during a geomagnetic storm. “It didn’t look like any auroras I have ever seen before,” says Chad Blakley, the director of Lights over Lapland. One of his tour guides, Miquel Such, video-recorded the phenomenon:

A G1-class geomagnetic storm was underway on Nov. 3rd when the blue ribbon appeared. Webcams saw it first at 1615 UT (5:15 p.m. local Abisko time). It rapidly brightened to naked-eye visibility, then sank below the horizon 30 minutes later. The whole time, regular green auroras danced around and seemingly in front of it: movie.

But what was it?

Space physicist Toshi Nishimura of Boston University took a look at the video. “It looks really odd if it’s aurora,” he says. “One auroral arc shouldn’t cut across another auroral arc without disturbing it, so it’s hard to explain this from an auroral physics point of view.”

Above: The blue ribbon over Lake Tornetrask. Photo credit: Claudio Comi

Another possibility is rocketry. Since late October Russia has been conducting ICBM firing exercises in the Barents Sea with the nuclear-powered missile cruiser “Peter the Great” in the area for combat training. Rocket exhaust has been known to create displays like this in the past.

However, no one saw a rocket. Multiple witnesses in Abisko agree that nothing streaked across the sky before the blue band appeared.

For now, the blue ribbon remains a mystery. Any photographers who caught it are encouraged to submit their images. Photos from different locations may help determine the height of the emission. And, of course, if anyone saw a rocket, let us know!

more images: from Hendrik Zwart of Sjøvegan, Salangen Kommune, Norway

MYSTERY SOLVED? On Nov. 3rd, Russia’s nuclear submarine Generalissimus Suvorov test-fired an ICBM from beneath the White Sea. This might be linked to a “blue aurora” widely seen from northern Sweden and Norway on the same date. The sightings are described below. The Russian military has issued a NOTAM (Notice to Airmen) for additional missile firings through Nov. 5th. Sky watchers in the area should remain alert for unusual auroras.

Circumstantial evidence is mounting that the blue apparition was, in fact, a Russian rocket. Back in October 2017 sky watchers across northern Scandinavia saw a similar display documented on Spaceweather.com. It was caused by a Topol ICBM launched from the Plesetsk space center 800 km north of Moscow.

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BlueWalker 3 Sightings

Nov. 13, 2022: Evidence is mounting that AST SpaceMobile’s BlueWalker 3 satellite has unfurled its its huge antenna. Multiple observers have seen the satellite shining like a 1st magnitude star–a 50-fold increase in brightness compared to just a few days ago. Paul Maley of Arizona saw it in bright morning twilight on Nov. 11th, and Gary Dowdle of Texas caught it just before sunrise on Nov. 12th:

“The satellite was very low in the northeastern sky, about 16.5 degrees above the horizon,” says Dowdle. “Nevertheless, it was easily visible to the naked eye at magnitude +2 just below the handle of the Big Dipper.”

Paul Maley saw it again on Sunday morning, Nov. 13th. “It came out of Earth’s shadow at magnitude +3 then steadily brightened to magnitude +1,” he says. “Its visual profile remains unchanged over the last 3 days. The spacecraft appears completely stable with no signs of tumbling.”

BlueWalker 3 is a revolutionary communications satellite designed to provide cell phone service from space. To detect weak cell phone signals from Earth’s surface it needs a very large antenna. BlueWalker 3’s is about the size of a squash court:

Astronomers have worried that BlueWalker 3 could become one of the brightest objects in the night sky, reflecting bright beams of sunlight into telescopes on the ground below. Those fears have not been fully realized. If the satellite is really only as bright as a 1st magnitude star, then it would be no worse than, say, China’s Tiangong space station or the ISS.

It may be too soon to relax, though. While this is only a single satellite for now, Bluewalker’s maker AST SpaceMobile plans to launch more than 100 larger satellites called BlueBirds. These satellites could be more than twice the size of BlueWalker 3 and much brighter. Flocks of Bluebirds could ruin a lot of astronomical observations.

Set against this detriment to astronomy is the good these satellites could do by providing emergency services and cell phone connectivity to remote areas. AST SpaceMobile explains.

You can help monitor BlueWalker 3. Morning and evening flybys are currently happening over the USA. Check Heavens Above for local flyby times and let us know what you see.

UPDATE: The CEO of AST SpaceMobile confirmed in a Tweet this morning that BlueWalker 3 has indeed unfurled its antenna, accounting for the observations described below. He also shared images of the antenna taken from orbit with different sun angles.

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