Aurora alert tonight through Monday night Nov. 9-10

Aurora smolders beneath the Big Dipper tonight November 9th around 7 p.m. Credit: Bob King

Around 7 p.m. this evening, just before moonrise, a smoky green glow fired up beneath the Big Dipper low in the northern sky. The Moon rose and clouds soon followed, but we might be in for a couple nights of northern lights.

Cirrostratus clouds at moonrise this evening refracted moonlight into a pretty halo. Caught in the semi-circle is the Hyades star cluster (lower right). The Pleiades are at upper right. Credit: Bob King

A coronal mass ejection that launched from the Sun on November 7th will arrive overnight and could produce minor to moderate (G1-G2) geomagnetic storms now through midnight Monday night. The strongest activity is expected between 3-9 a.m. (CST) tomorrow morning.

A blast of high-speed electrons and protons from the Sun on November 7 looks like it may affect Earth overnight and into Monday. Credit: NASA/ESA

Tonight’s little taste will hopefully be a sign of more to come.

Monster sunspot could stir up auroras

The sun photographed this morning by NASA’s Solar Dynamics Telescope at 11:30 a.m. CDT this morning October 18. Credit: NASA

Not today and not tomorrow, but a monster sunspot group rounding the eastern limb of the sun could spunk up the fall aurora season. Active region 2192 harbors a Jupiter-sized sunspot that’s just now visible with the naked eye using a safe solar mylar filter or #14 welder’s glass. I spotted it very close to the southeastern edge of the sun today. In the coming days, it will rotate into better view, making for an easy catch with the naked eye or small telescope. I can’t emphasize enough the importance of a safe filter. You can purchase one HERE for naked eye viewing or HERE for your telescope.

Coronal mass ejection shot out by flare activity in new sunspot group 2192 on October 14 before it even rounded the sun’s limb. Image from the SOHO coronagraph. Click for video. Credit: NASA/ESA

Even before the behemoth came into view, it spawned a brilliant coronal mass ejection on October 14 and several M-class medium strength flares. If we assume that the giant spot stays potent, the sun will rotate it around to face Earth in about 6 days. Flaring and other activity would then stream in our direction.

It will also spice up the partial solar eclipse next Thursday afternoon. Watch for the black limb of the moon to not only eclipse the sun but this sunspot too!

Update: Sunspot group 2192 unleashed an strong X-1 class flare around midnight Oct. 18-19. Any material it may have launched into space would have missed Earth by a wide margin because of the group’s position near the sun’s edge.

Auroras in the north tonight Oct. 14-15

Aurora low in the northern sky around 10:30 p.m. CDT this evening October 14, 2014. Credit: Bob King

Earlier this evening, a glancing blow from a solar blast that left the sun on October 10th jiggled Earth’s magnetic domain to produce a modest display of northern lights. Forecasters originally expected the coronal mass ejection (CME) to miss Earth. My astronomy class and I noticed a low arc in the north as early as 8:30 p.m. A half hour later, the arc broke apart into a beautiful set of evenly-spaced rays across the northern sky.

These slowly faded back to a quiet glow as if the aurora decided to take a nap and then re-brightened about 9:30. Right now at 11 p.m. the display has returned to a quiet arc about 5 degrees above the northern horizon directly below the Big Dipper. Something about it reminds me of a pale green feather boa.

The Kp index, a measure of how magnetically disturbed the upper atmosphere is, hit 5 this afternoon and evening, the mark of a minor geomagnetic storm. Auroras are usually seen across the northern border states when Kp=5. Credit: NOAA

NOAA space weather shows a G1 minor geomagnetic storm underway since the afternoon. Activity may be dropping off now, but it’s hard to say for sure, so keep a lookout for auroras tonight if you live in the northern states and southern Canada. Besides aftereffects of the solar blast, a chance for more auroras will continue the next couple nights due to “solar sector boundary crossings”. These are changes in the direction of the magnetic field within the solar plasma (electron and proton mix) that continually streams from the sun called the solar wind.

Twin solar storms may stoke auroras tonight Sept. 11-12

A CME or coronal mass ejection from the sun on September 9 is expected to pass Earth later today and possibly spark auroras tonight. Credit: NASA/ESA

(Click HERE for updates))

Two bursts of solar particles propelled by flares on September 9th and 10th are expected to arrive starting tonight and possibly touch off a moderate G2 geomagnetic storm. Translation: auroras may bloom in the next few nights!

A moderate M4 flare occurred early on September 9th followed by a more powerful X1.6 yesterday afternoon. Provided the magnetic field the particles come packaged in points in the right direction – south – these bursts have good potential for creating auroras tonight and again over the weekend.

A second, Earth-directed CME leaves the sun in the wake of the X1.6 flare on September 10th. Credit: NASA/ESA

The timing is good because the moon is past full and won’t be too bright. During a moderate storm, auroras are often seen across the northern tier of states and Canada. According to the latest NOAA space weather forecast, activity should kick up but remain shy of storm level from 9 p.m.-midnight Central Daylight Time tonight September 11th.

The brunt of the storm is expected from 1-4 a.m. tomorrow morning the 12th with effects lasting until 7 a.m.

This may only be the start of an even stronger storm anticipated Friday night and continuing into the weekend beginning from yesterday’s flare. That one blasted material directly toward Earth. Always a good omen for auroras.

Earth’s magnetic bubble, generated by motions within its iron-nickel core and shaped by the solar wind, is called the magnetosphere. It extends some 40,000 miles forward of the planet and more than 3.9 million miles in the tailward direction. Credit: NASA

As always with northern lights, keep in mind they’re fickle. Most of the time, Earth’s magnetic defense – a humongous, teardrop-shaped bubble of magnetism called the magnetosphere –  acts as a bulwark against strong solar winds, letting them slide by harmlessly. We’ll see what happens on this round, but I’m optimistic.

The Earth weather forecast for my locale is mostly clear tonight, so I’ll be monitoring the sky. Stop back later for an update.

* UPDATE 9 p.m. CDT: Quiet so far. Auroras still holed up in Hudson Bay and Quebec. The magnetic field direction of the arriving wind from the sun shows a lot of variation (see ACE satellite plot, topmost graph showing Bz) rising and falling from positive to negative. Negative is good! A prolonged stay at -10 or lower increase the chance of seeing the aurora.

Aurora alert tonight Aug. 26-27 – updated

Painting by Etienne Trouvelot of a spectacular aurora observed on March 1, 1872.

North Americans skywatchers missed the last week’s aurora by the skin of our teeth. By nightfall, the whole display, enjoyed earlier from Scandinavia, went to heck. Maybe tonight will be different.

For the past few days NOAA space weather forecasters have been predicting a minor geomagnetic storm (Kp = 5) from incoming blasts of solar particles called coronal mass ejections that departed the sun on Aug. 22. ‘Minor’ often translates to an auroral arc (sometimes two) low in the northern sky pierced by occasional rays.

No great shakes, but if you live in the northern U.S. and southern Canada, be aware you might be visited by the green ghost. Activity should commence after sunset and peak between 1-4 a.m. CDT tomorrow morning Aug. 27.

Maybe we’ll get burned again. But you wouldn’t want me to keep this all to myself, would you?

* UPDATE 5:30 a.m. CDT: Big auroras lit up the northern sky this morning. Lots of arcs and long rays seen from Duluth, Minn. If you live in the northern third of the U.S. and it’s still dark, go out for a look.

Aurora alert tonight Aug. 2 / Rosetta comet update – striking new details!

A CME or coronal mass ejection erupting on July 30 may lead to a small display of northern lights tonight. Jupiter at right in this photo made with the coronagraph on the Solar and Heliospheric Observatory. Credit: NASA/ESA

Minor auroras might visit skies across the northern U.S. and southern Canada tonight, the result of a coronal mass ejection from an erupting filament on July 30. Filaments are clouds of hot hydrogen gas suspended in the sun’s lower atmosphere. They often stay put for days, but a little magnetic instability can launch one into space.

Material from the filament is expected to begin arriving this afternoon and continue into the evening hours. I’ll have an update later if auroras materialize. Meanwhile, keep an eye on the northern horizon when it gets dark tonight. Fortunately, the moon will only be a half and not wash out the sky.

Comet 67P/Churyumov-Gerasimenko at 621 miles (1,000 km) on August 1. Wow! Look at that richly-textured surface. This photo has higher resolution than previous images because it was taken with Rosetta’s narrow angle camera. The black spot is an artifact. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Rosetta sent two new pictures of Comet 67P/C-G from 621 miles (1,000 km) away that show striking new details including new artifacts. I’ve done some digging around and discovered that the dome-like features and ‘craters’ seen on the past couple photos are really artifacts due to image processing.

Wider-angle and lower resolution navigation camera photo of the comet. More artifacts are seen including what look like bumps or boulders. Credit: ESA

You’ll see a black spot (artifact) in the narrow-angle camera and another dome artifact in the Navcam photo. They’re generally pairs of bad pixels that get smoothed out in processing to look like real features on the comet’s surface. Those should go away once the spacecraft is close enough for the comet to fill the field of view.

Polka dots and sunbeams a solar observer’s dream

Sunspots speckle the sun like polka dots in this photo taken early this morning by NASA’s Solar Dynamics Telescope (SDO). The largest spot (right of center) belongs to sunspot group 2055. The view is very similar to that seen through a typical amateur telescope equipped with a safe solar filter. Sunspots are regions where magnetic energy is concentrated on the sun’s surface. Credit: NASA

For a change it was wonderful to show people a heavily speckled sun at Astronomy Day festivities yesterday. If it’s clear – rare enough in itself – sunspots are usually little more than crumb-sized and look like flecks of dirt or dust through the eyepiece.

Kids and adults eager to see sunspots queue up at Jim Schaff’s dual telescopes, which showed the sun in both visible light and deep red hydrogen-alpha. Schaff, of Duluth, is at left. Credit: Bob King

But this week the past few days, the sun’s been showing off a half dozen spots as large or larger than the planet you toil upon. There are currently at least 8 numbered sunspot groups. One of them, the leader spot in group 2055, was easily seen through a #14 welder’s glass this morning.

A C4-class flare in sunspot region 2055 early yesterday evening May 10 glares in this photo made in ultraviolet light by SDO. More flares up to M-class are possible from this region in the coming days. Credit: NASA

To be visible with the naked eye (with filter), a sunspot or sunspot group has to extend some 31,000 miles (50,000 km) or about 4 times the diameter of Earth. While enormous, about 2-3% of sunspots and sunspot groups or about 100 per 11-year solar cycle can be seen by a dedicated solar observer, proving you don’t need a telescope to follow the general trend of the 11-year sunspot cycle.

The first drawing of sunspots was made by English monk John of Worcester in 1128 A.D.

The first written records of sunspots come to us from the Chinese as long ago as 800 B.C. Court astrologers in China and Korea kept tracks of spots because they believed they foretold important events. The earliest known drawing of sunspots was made almost 500 years before the invention of the telescope by English monk and chronicler John of Worchester. On Dec. 8. 1128 A.D., Brother John wrote:

“…from morning to evening, appeared something like two black circles within the disk of the Sun, the one in the upper part being bigger, the other in the lower part smaller. As shown on the drawing.”

First photo of the sun using the daguerrotype process taken by Fizeau and Foucault on April 2, 1845. Though fuzzy, you can still make out sunspot groups and the basic dark umbra-lighter penumbra structure of the spots. Credit: ESA

His sighting was followed five days later by a red aurora recorded over Korea. The two may have been related.

As long as we’re talking firsts, the first successful photograph of the sun and sunspots was made on April 2, 1845 by French physicists Louis Fizeau and Leon Foucault on daguerrotype with an exposure of 1/60 of a second. It looks pretty rough but photography only improved from there.

Nowadays, anyone with a safe solar filter for either naked eye or telescope use can see what the sun’s up to. Solar telescopes in orbit and on the ground photograph the sun almost continuously. NASA’s dual STEREO orbiting solar probes even show us what’s happening the side facing away from Earth.

A prominence eruption blasted a CME or coronal mass ejection off the northeast side of the sun very early this morning. It’s not Earth-directed. This photo was taken by the Solar and Heliospheric Observatory (SOHO) which uses a disk to block direct sunlight. Credit: NASA/ESA

We not only want to learn more about how the sun works, but we’re justifiably concerned about its storms and how they affect our planet.

Strong solar flare creates rare magnetic ripples in Earth’s atmosphere

Energy stored in twisted magnetic fields above sunspot group 2017 was released a as a strong X1-class flare at 12:52 p.m. CDT March 29. Powerful X-rays from the flare sent magnetic currents through Earth’s upper atmosphere minutes later. Credit: NASA

An fast, intense X1-class solar flare yesterday afternoon not only blasted a cloud of solar electrons and protons into space but also sent magnetic ripples across Earth’s upper atmosphere creating what astronomers call a magnetic crochet.

X1 solar flare on March 29, 2014

Normally it takes an average of 4 days for a cloud of fast moving solar particles called a coronal mass ejection or CME to reach the Earth. Fast ones moving at 620 miles per second (1,000 km/sec) arrive in about 42 hours. But energy levels rose so rapidly in yesterday’s flare that Earth’s atmosphere was affected only minutes after the onset of the storm.

How could something from the sun get here so fast? Well, it does everyday. Sunlight traverses the 93 million miles between Earth and sun in just 8.3 minutes. There are many forms of light from radio waves to visible light to X-rays. Flares are so powerful they kick out waves of light energy across the entire spectrum from radio to deadly gamma rays.

The Earth’s ionosphere, divided into layers D, E and F, begins about 37 miles high and extends nearly to space. Solar and cosmic radiation strips electrons from atoms turning them into ions, which respond to electrical and magnetic fields. Credit: Rutherford Appleton Laboratory

A burst of X-rays from sunspot region 2017 arrived 8.3 minutes after the blast and increased the electrical conductivity in the D and E layers of Earth’s ionosphere by stripping electrons from the atoms there, making electric currents flow more easily. Because moving electrical currents create magnetic fields, the flare caused a sudden jump or ripple of magnetic energy to pulse through the ionosphere. As the flare subsided, those layers returned to normal.

You can see for yourself how an electric current creates a magnetic field by holding a compass near an operating electric shaver or hairdryer. As you move the shaver back and forth, the compass needle will swing wildly as it responds to the local magnetic field created by the flow of electrons in the current.

Even though we can’t see them, magnetic fields have very real effects.

Magnetic crochets are rare because they only occur during large flares that peak quickly. They’re also typically recorded at locations where the sun is overhead at the time of the flare.

Just one more way the sun touches our lives. As for the particles propelled by the flare, most of them took off northward of Earth but a glancing blow is expected around April 1 when Arctic observers may see a nice show of northern lights during their rapidly diminishing nighttime hours.

Big sunspot livens up a quiet sun / Chance for auroras overnight Feb. 1-2

Sunspot region 1967 dominates the solar disk in this photo made late Jan. 31 by the Solar Dynamics Observatory. Credit: NASA

Sunspot group 1967 burst onto the scene on Jan. 28. Now it’s big enough to easily see with the naked eye through a safe solar filter. The group’s twisty, complex magnetic field has already ignited a significant M6 flare on the 30th with a 60% chance for more M-class flares in the next three days.

The expanding cloud of solar plasma called a coronal mass ejection caught blasting away from sunspot group 1967 on Jan. 30 photographed by the Solar Heliospheric Observatory. Credit: NASA/ESA

The Jan. 30 event kicked out a high-speed proton-electron soup called a coronal mass ejection, a part of which will graze Earth overnight tonight (Feb. 1-2) and may spark a northern light display at high latitudes. Of course there’s always a chance southern Canada and the northern border states of the U.S. will see some action, too.

Since there’s been such a dearth of auroras of late, I wanted to share this bit of potentially good news. I’ll post updates if the lights make an appearance.

Why no aurora last night? Here’s the scoop

Maybe you were expecting something more like this last night? Join the club. Credit: Bob King

Did you plan a vigil the past two nights in hope of seeing the northern lights? I know I did. Lost some sleep over it for sure. As it happened, the display never materialized. Yes, the expected brush with particle blast released by the Jan. 7 solar flare did blow by Earth, but only managed to stir up a nice show in Arctic regions like northern Norway and Finland during afternoon hours for U.S. time zones.

Since auroras in that part of the world are as common as doughnuts, I think we can say this outburst was officially a flop.

I spoke with Joe Kunches, space scientist at the NOAA Space Weather Prediction Center, this morning about the matter. When I first rang, he told me he’d have to call back because the staff was just going into a meeting about this very topic. Hopefully no heads rolled.

Kunches described the solar blast as an empty bottle. “There was nothing in it,” he said. Despite the fact that it made a direct beeline for the planet, there was no way for scientists to know the strength and direction of the magnetic field embedded in the particle cloud.”

The Solar and Heliospheric Observatory (SOHO) monitors the sun from the stable L1 Lagrange Point a million miles sunward of the Earth. The green swirls around the Earth represent its magnetic bubble called the magnetosphere. Credit: NASA/ESA/Steele Hill

“The CME (coronal mass ejection) was slower than the model suggested by 8 hours, which sometimes means that it will be weaker than expected,” said Kunches.

“This illustrates our biggest forecasting challenge,” he went on. “We can see the path but can’t know it contains a strong magnetic field pointing in the right direction by the time it arrives at Earth the way a forecaster knows the barometric pressure of a hurricane.”

What happens to the swirling, whirling cloud of subatomic particles released during a flare must rank a close second to chaos itself. Scientists make detailed observation with dedicated space observatories like SOHO, the Solar Dynamics Observatory and STEREO probes and then model the behavior of the incoming particle winds as best they can:

“Even if they’re right when it leaves the sun, there’s no guarantee it will be that way when it arrives,” said Kunches. CMEs can rotate and deform in unpredictable ways. The key to a solid prediction of auroras very much depends on the direction of the magnetic field within the cloud when it sweeps by Earth, a factor called Bz.

The interplanetary magnetic field, created by a wind of solar plasma entwined with magnetic fields, departs the sun in the shape of a gigantic spiral. As waves of varying strength, density and direction pass by Earth, our planet’s magnetic field occasionally hooks up with the sun’s, making auroras likely. Credit: NASA

Embedded within the sun’s plasma swirls are portions of its magnetic field. As that material – called the interplanetary magnetic field (IMF) – sweeps past Earth, it normally glides by, deflected by our protective magnetic field, and we’re no worse for the wear. But when the solar magnetic field points south – called a southward Bz – it can cancel Earth’s northward-pointing field at the point of contact, opening a portal. Once linked, the IMF dumps its baggage of high-speed particles into our atmosphere to light up the sky with northern lights.

The Jan. 7 solar gust arrived at Earth with a northward pointing Bz. With no coupling, nothing happened. Perhaps you’ve watched the real-time red trace on the ACE satellite’s Bz read-out. For most of the past two days that squiggly line has been “flat as a pancake” as Kunches put it, which did not bode well for auroras. At any time it could have dipped south but never did.

Click to watch a video of the solar wind linking up with Earth’s magnetic field behind the planet, sparking a particle cascade and auroras in our upper atmosphere.

While no method is absolutely guaranteed, I recommend the following sites to check before you get in your car and drive 100 miles to see an aurora:

* ACE Dynamic Plots – The red trace for Bz is the one you’re interested in. If the line dips well below the centerline to -10 or lower, auroras may be likely.
* Ovation Aurora – Simulation of the auroral oval (extent of aurora) based on live satellite data. Pay attention to the location of the red curve showing the southern extent of auroral visibility.
* Kp index – magnetic activity indicator updated every 3 hours. A yellow bar (Kp=4) is a good sign aurora might be visible from the northern U.S. and southern Canada. A red bar (Kp=5 or higher) indicates a larger storm and more extensive aurora.

By the way, Kunches says that the CME has blown by and doesn’t expect any northern lights for tonight, so catch up on your sleep. In the meantime, put on your philosophical cap and reflect about how much we really don’t know about the world. Always a great motivation to learn more.