Tag Archives: CME

Aurora alert tonight May 17-18, 2013

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This map created with satellite data for 11:30 p.m. CDT May 17 shows the extent of the northern auroral oval, one of two permanent caps of aurora centered on Earth’s north and south geomagnetic poles. Normally the oval is small and snugged up over Hudson Bay. Tonight it’s expanded southward and could produce auroras across the northern border of the U.S. Click to see current oval. Credit: NOAA

If it were clear here in Duluth, I’m sure we’d be seeing northern lights. The Kp index, an indicator of magnetic activity around the Earth, shot up to “5″ or minor storm level around 11 p.m. Central time this evening (Friday). From the satellite plot, it appears the auroral oval extends across southern Canada almost to the U.S. border.

Since the aurora is quite high – around 60-200 miles – it’s visible a fair distance to the south of that line. In other words, northern parts of Minnesota, Michigan, Wisconsin, N. Dakota, Montana and Washington may get treated to the sight of northern lights overnight.

Sunspot region 1748 still has the potential for more solar storms. Since the group’s now becoming more face-on to Earth, additional flares could send CMEs in our direction. Another flare on May 17 sent material expected to arrive on the 19th. Credit: NASA

Be sure to take a look at the northern sky tonight for arcs and rays of aurora. As you might guess, the cause for this show lies with the recent X-class flares sunspot region 1748 has been pounding out over the week. Our planet was expected to get a glancing brush from a coronal mass ejection (CME) overnight from one of the recent blasts. Let us know if you see anything. And get ready for May 19 – Sunday – when another blast could spark an even more auroras.

Lizard Lemmon Comet loses tail, grows a new one

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Comet C/2012 F6 Lemmon photographed on May 15 showing its bluish, ion tail (bottom) beginning to peel away from the comet. The dust tail sticks out to the left. A wispy, new gas tail is already growing above the departing one. Credit: Damian Peach

Solar winds snapped off Comet Lemmon’s ponytail this week and sent it reeling into space. Not to worry. Comets possess the remarkable ability, shared by many species of lizards, to grow new ones. A lizard loses its tail to distract and escape a predator; a comet because its charged atoms – called ions – interact with the breezy blasts of charged particles from the sun called the solar wind.

Magnetic fields in the solar wind tore off Comet Lulin’s tail on Feb. 4, 2007. You can clearly see it falling away in the bottom frame. Credit: Joseph Brimacombe

One day Comet Lemmon was minding its own business and then on Wednesday morning, one of its two tails underwent a “disconnection event”. Comets frequently grow two tails when they orbit near the sun – a pale yellow one of fine dust and a blue one of ionized (electrically charged) gas. The blue color comes from ionized carbon monoxide which fluoresces blue when excited by ultraviolet light from the sun. The larger particles in a comet’s dust tail have no electric charge and aren’t affected by the solar wind; they get pushed away from the comet’s head by the pressure of sunlight.

Charged particles from the sun – electrons and protons – plow through the solar system and continuously interact with comets creating picturesque kinks and ripples in their ion tails. Wrapped up into this electrical mix are solar magnetic fields with north and south-directly poles similar to those on a horseshoe magnet.

 

Invisible magnetic field lines are made visible around a bar magnet when you sprinkle iron filings around it. The sun’s wind likewise has lines of magnetic force embedded within it created by moving charged (electric) particles.

Electricity and magnetism go hand in hand. A spinning magnet creates an electrical field and an electric current creates a magnetic field. Every time you turn on a lamp, the wires inside the cord are looped by invisible but very real magnetic fields.

Solar flare eruptions like the powerful X-class flares earlier this week can direct huge clouds of magnetized (and electrified) clouds of gas called coronal mass ejections or CMEs into space. When one smacks into a comet, it can rip its tail right off.

Magnetic field lines bound up in the sun’s wind pile up and drape around a comet’s nucleus to shape the blue ion tail. Notice the oppositely-directed fields on the comet’s backside. The top set points away from the comet; the bottom set toward. In strong wind gusts, the two can be squeezed together and reconnect, releasing energy that snaps off a comet’s tail. Credit: Tufts University

Comets present obstacles to the solar wind. The magnetic field carried by the sun’s constant wind gets pushed back by the comet’s electrified gases causing it to drape and flow around the comet’s head. That’s what forms the streamlined blue ion tail in the first place. But when an especially powerful blast of wind blows by, it can elbow its way around the backside of the comet and reconnect with itself, releasing a burst of energy that snaps off the tail.

Diagram showing how a CME slams into a comet (B) to create a tail disconnection event, known in the biz as a DE. Soon enough the comet grows a new one (D). Credit: NASA

In a very real sense, Comet Lemmon experienced a space weather event much like what happens when a powerful solar wind reconnects streams around Earth’s magnetic field and reconnects on the back or nightside of the planet. The energy released sends zillions of electrons and protons screaming down into our upper atmosphere where they stimulate the air molecules to produce auroras. One wonders whether comets might even have their own brief displays of northern lights.

As the solar wind flows away from the Sun, it creates a spiral-shaped interplanetary magnetic field (IMF). Two to four sectors – where the field is pointed toward or away from the sun – spin out every solar rotation (27 days). Each sector Credit: NASA

It’s unclear what pinched Lemmon’s tail since all four large flares from sunspot group 1748 and their associated CMEs weren’t directed at Comet Lemmon.

Maybe the comet crossed a sector boundary where the magnetic field carried across the solar system by sun’s steady breeze changed direction from south to north or north to south. When it sped across the older field wrapped around Lemmon, the two once may have linked up in a burst of energy.

When a lizard loses its tail, it may gain its life, but still suffer for the trouble. For a time, its sense of balance is compromised and important fat reserves stored in the tail aren’t available. Comet Lemmon will be no worse for the wear. As soon as the old tail drifts away, a new one sprouts in its place, cooked up by the ever-steady sun.

Read more about tail disconnections HERE; check out a map for finding Comet Lemmon HERE.

A 3rd X-class flare rocks the sun

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The latest X3.2 flare in far ultraviolet light at 8:16 p.m. CDT Monday evening May 13 (May 14 Universal Time) photographed by the Solar Dynamics Observatory. Credit: NASA

Solar activity’s been rising like nobody’s business. Two of the year’s most powerful flares fired off from the sun’s backside late Sunday and at least 8 spot groups speckle the sun’s white-hot surface today.

Another ultraviolet picture of the sun taken by NASA’s STEREO Behind spacecraft late on May 13. The flare looks like a giant spike because the brilliance of the explosion saturated the camera sensors. STEREO Behind orbits well behind Earth and sees a part of the sun’s backside not visible with Earth-based telescopes. Click to learn more about the STEREO probes. Credit: NASA

Now we can add a third strong X-ray class flare, an X3.2 that spewed a vast cloud of high-speed solar gases called a coronal mass ejection (CME). Lucky for Earth, it was directed – as the other flares were – away from our planet off the eastern edge of the sun’s disk.

The most energetic flare measured in the modern era occurred on November 4, 2003 during the last solar maximum. No one knows how truly strong it became since the sensors topped out at X28. But any flare in the X-category can affect everything from GPS satellites to radio communications, satellite electronics and even fry poorly-protected power grids.

The sun in normal white light late Monday with sunspot groups labeled. Region 1748 – site of the strong flares of the past few days –  is just coming into view at far left. Credit: NASA

Solar flares typically occur in sunspot groups where magnetic energy is concentrated. The  solar surface, which bubbles and churns like a monster pot of hot oatmeal, brings opposite magnetic fields (north and south poles) in contact with one another. When they reconnect, the sudden release of energy heats solar gases to many millions of degrees and blasts billions of solar electrons and protons into space as a CME.

The amount of energy from a big flare like the ones we’ve seen recently equals millions of thermonuclear (hydrogen) bombs.

A healthy CME (coronal mass ejection) in the wake of the most recent X3.2 flare late Monday. This photo was taken by the Solar and Heliospheric Observatory which uses a special mask to block out the bright sun to better photograph it outer atmosphere. Credit: NASA / ESA

The sunspot group responsible for all the current feistiness goes by the name of 1748; it’s just coming around to the sun’s front side. Though highly foreshortened because we’re peering at it along the extreme edge of the sun, you can tell it’s a big one. Let’s hope it kicks and sputters its way to a northern lights display without any serious damage to our favorite toys.

Earth’s skies may dance in auroral green St. Patrick’s Day

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A solar flare in the early morning hours of March 15 CDT sent a cloud of high-speed subatomic particles called a coronal mass ejection toward the Earth. It’s expected to arrive overnight tonight through Sunday. A disk blocks the sun in this photo taken with the Solar and Heliospheric Observatory (SOHO), allowing a better view of the cloud. Credit: NASA / ESA

I’ve got green on my mind and it’s not because I’m Irish. On March 15 a magnetic filament – a strand of solar flame silhouetted against the sun’s brilliant disk – erupted in a long-duration flare that sent a blast of solar plasma directly toward the Earth. Traveling at 2 million miles per hour, the cloud of high-speed electrons and protons will slam up against our planet’s magnetic bubble and possibly touch off an auroral storm.

Auroral display over Duluth Oct. 8, 2012. The green color, the most common seen in northern lights, is caused by oxygen atoms in our atmosphere energized by high-speed electrons from the sun. When the atoms return to the “unexcited” state, each releases a bit of green light. Photo: Bob King

Minor auroras are forecast for mid-northern latitudes tonight March 16 with a chance for a major storm on Sunday. If you live in the Arctic, get ready for a good show – chances for a major to severe storm stand at 70% Sunday (20% for mid-latitudes).

Wide-field view of the same coronal mass ejection taken by SOHO around 3 a.m. CDT March 15. Venus is to the lower right of the sun. Credit: NASA / ESA

These are the best numbers I’ve seen in some time, so be on the lookout this weekend for green rays step-dancing across the northern sky.

As always, keep an eye on the Kp index and the extent of the auroral oval, both of which are useful indicators of auroral activity. If the Kp index bar is colored red (equal to 5 or more), there’s a good chance auroras are out at least for the northern U.S. and southern Canada.

As I write this in the wee hours of Saturday morning, the index is already rising and auroras appear to be pushing into the far northern U.S. If it wasn’t for a heavy snow falling, I’d go out for a look-see right now. More updates later today.

Pint-sized auroras possible this weekend Jan. 18-20

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Jarno Pääkkönen of Finland took this photo of a very colorful northern lights display Thursday morning, Jan. 17, 2013 in Kontiolahti, Finland, latitude 62.7 degrees north. Details: Canon 5D Mark III camera, 20-25 seconds at f/4 and ISO 2000. Click photo to see more of his work.

A heads-up for all you aurora watchers out there. The NOAA space weather forecast  calls for a 30 percent chance for minor geomagnetic storms tonight Jan. 18 through the 20th. That means there’s a small possibility for auroras in the northern U.S. and a much better one for Arctic regions.

Thomas Kast, who also hails from Finland, shot this photo the same night near Rokua, Finland. “Northern lights are never boring!” he says. Kast had to walk through deep snow in -16 F temperatures to get the shot he wanted. Click to see more photos on his Facebook page.

The cause behind the next expected wave is another CME or coronal mass ejection. Similar enhancements in the sun’s wind of subatomic particles have been responsible for recent, widely-visible auroras across Finland, Norway, Iceland and Canada. We came close to seeing minor auroras in the northern U.S. last night, but the burst of activity that visited the Scandinavian countries earlier in the day had died down by the time darkness cloaked the U.S.

Give a look up if it’s clear this weekend, and if you see the northern lights, drop us a report by clicking on the Comments link below.

Sun blows Earth a kiss – will she blush?

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Three views over 2 1/2 hours of a coronal mass ejection or CME as it burst off of the sun headed for Earth this morning Jan. 13, 2013. The images were captured by NASA’s Solar Terrestrial Relations Observatory (STEREO). Credit: NASA/STEREO

The sun hurled a coronal mass ejection (CME) in Earth’s direction this morning at 1:24 a.m. (CST). This proton-electron particle spray may reach us within 1 to 3 days and possibly make the Arctic sky blush with auroras. We’ll have to wait and see.

Since this CME left the sun at only 275 miles per second, it’s not likely to kick up a big storm. The biggest blasts can send particles our way at nearly ten times that. If they succeed in connecting with Earth’s magnetic envelope, the magnetosphere, electrons and occasionally protons spiral down along magnetic field lines into our atmosphere to produce auroras. We don’t have to worry about these guys hitting us directly on the ground; we’re protected by the planetary magnetic field and the air above us.

Saturn’s tiny moon Daphnis (the point of light) clears the 26-mile-wide Keeler Gap, named after 19th century American astronomer James Keeler, in Saturn’s rings. The gravity of the moon also creates the ripples seen along either side of the vacancy. Credit: NASA/JPL-Caltech SSI

One of my favorite things to do is dig through image archives looking for gems to share. A recent photo of Saturn’s 5-mile-diameter moon Daphnis raising sawtooth-like waves in Saturn’s Keeler Gap caught my eye. The picture, taken by the Cassini spacecraft last August and released in late December 2012, shows a lovely series of ripples on either side of the Keeler Gap, a debris-free zone about 26 miles wide near the outer edge of Saturn’s A-ring.

Closeup of Daphnis and its gravitational wake photographed by Cassini on July 5, 2010 from a distance of 45,000 miles.  Click to enlarge. Credit: NASA/JPL/SSI/ color composite by Gordan Ugarkovic

As it circles the planet on an inclined orbit, Daphis’ gravity tugs on the icy ring particles to clear a gap and create the ripples. The rings are only about 33 feet thick despite their vast extent and consist primarily of individual chunks of ice in their own slightly different but unique orbits about the ringed planet.

Although difficult to see in the picture, the ripples rise up about 1 mile above the ring plane. Notice there are two sets. Material along the inner edge of the gap orbits faster than the moon, so that the ripples precede Daphnis in its orbit. Material on the outer edge moves slower than the moon, creating a set of trailing waves.

Nature has many sculptors and tools with which to fashion the most delightful of cosmic structures. Put a smidge of a moon in the right place and it’s not long before something marvelous happens.

Gusty solar winds could mean auroras tonight

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Auroras greeted early risers this morning. This photo was taken by Lyle Anderson of Duluth, Minn. just after 6 a.m.

I know the fall leaves steal the show, but the sky can be just as colorful day or night. This morning we got swiped by a wind of particles from a recent coronal mass ejection (CME) from the sun. Those living in the northern U.S.and Canada who were fortunate enough to be up after midnight probably saw the subtle pinks and greens of northern lights.  If you’re like me and missed it, more of the same is forecast for tonight.

An altocumulus cloud dressed up in iridescent hues of pink, blue-green and yellow yesterday afternoon from my home. Photo: Bob King

Care for more color? Yesterday afternoon a series of lenticular clouds tinged with the vivid pastels of iridescence paraded near the sun. You wouldn’t have noticed the colors at a casual glance because of the sun’s glare, but blocked by a building or tree, the clouds’ edges glowed in soap bubble pinks, yellows and greens.

Iridescence is seen in many places – peacock feathers, seashells, beetles, CDs, oil on pavement and yes, soap bubbles. Despite the intensity of the colors it produces, iridescence has nothing to do with pigments with a property of light called diffraction.  It’s similar to the way a rainbow is pure light and not an object.

Close up of the cloud above when it was nearer the sun with colors even more intense. Photo: Bob King

Recall that light is a series of waves much like waves made by boats motoring across a lake. Let’s imagine waves from those boats spreading until they come in contact. Some will complement each other to produce higher wave crests. This is called constructive interference; others will cancel each other out (destructive interference) to create flat water.

Extremely tiny, uniform-sized water droplets or ice crystals in certain types of clouds scatter light in all directions. The scattered light waves pass through one another just like the waves from our boats. Where crests coincide, that particular color or wavelength of light is reinforced and appears bright; where troughs coincide, the waves cancel or interfere with one another and that color is weakened or missing. Since light is composed of every color of the rainbow, a series of vivid, alternating hues results and tints the clouds’ edge.

Using a tree to block the sun, it was easier to see and photograph the clouds’ iridescence. Photo: Bob King

Large water drops won’t do. Only tiny ones diffract light well. In particular, the edges of clouds are best because they’re exceedingly thin. Light passes through a single layer of droplets and streams to your eyes without being absorbed by intervening droplets. Many clouds start with droplets of uniform size but they either grow too big, become mixed with larger droplets or are simply too far from the sun to show iridescence. That’s why the sight is uncommon.

Iridescent colors are also seen in soap bubbles when light waves from the top and bottom layers of the bubble film interfere (reinforce or cancel) one another. Credit: Wiki Commons

Iridescence happens in other ways. In soap bubbles, some of the light reflects off the outer layer while a portion continues through it and reflects off the layer’s inner surface. The second reflection is delayed by the extra time it took to penetrate the bubble and reflect back.

When the two rays rejoin, the crests and troughs aren’t lined up anymore. Scientists say they’re “out of phase” with each other. Some of the waves of each individual color of the spectrum reinforce each other; others interfere, creating delightful swirls of pastel colors.

Beetles employ a similar ruse. A thin, hard film on the surface of creature acts like the soap bubble film. Light reflecting from the interior is out of phase with that of the exterior, interference follows and we see striking colors as a result. Some insects and animals have a dark backing of melanin below the film to intensify the colors even more.

Wait a minute, didn’t we start out talking about the aurora? The places light will take us.

Auroras possible tonight through Monday Sept. 2-3

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A spectacular blast from the sun occurred Friday afternoon August 31. Material from the event will reach the Earth later tonight and may spark auroras. The photo was taken with the coronagraph – an instrument that blocks direct sunlight with a special disk. Credit: NASA/ESA

I had a sneaky feeling that if I wrote about expectations for the current solar cycle, auroras might return. Time to keep a look-out. They may be out as soon as tonight through tomorrow evening. A large filament of hot gas hovering in the sun’s atmosphere on August 31 became unstable and erupted, producing a flare and strong CME (coronal mass ejection). Visually it was one of the most dramatic blasts I’ve ever seen. A beastly-looking thing. The photo and video tell the story.


Wonderful video of the filament blasting off from the sun taken in UV light.

Material from the explosion wasn’t aimed directly at Earth – you can see much of it blasting off to the sun’s left side – but NOAA space weather forecasters predict it will graze the planet sometime tonight through tomorrow night. Those living at polar latitudes may well see a full bore storm; auroras are also possible for the northern U.S. and southern Canada. As of 8:45 p.m. tonight (CDT) the Kp index, an indicator of magnetic activity high overhead, has clicked up to “4″ – just below minor storm level. When it hits “5″ and the indicator bar is red, it’s worth pulling the curtain back to see if the aurora’s dancing around in the northern sky.

Auroras possible tonight Aug. 7 through Thursday morning

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A filament of hot gas connecting two sunspots group erupted and sent a pulse of plasma  into space the morning of August 4 (CDT). Earth is expected to receive at least a glancing blow from the material in the next couple days.

The Kp index, a fairly reliable indicator of geomagnetic (aurora) activity has crept up to just below minor storm level tonight. We’re clouded out in Duluth, Minn. but observers with clear skies living in the northern U.S. and southern Canada may want to keep an eye out tonight for northern lights. Truth in advertising: this is not expected to be a major storm.

The coronal mass ejection (CME) caught leaving the sun around 11 a.m. August 4, 2012 (CDT) by the coronagraph on the Solar and Heliospheric Observatory. Credit: NASA/ ESA

Skies in our region are expected to clear tomorrow evening when auroras are again likely. The cause goes back to a coronal mass ejection (CME) on August 4.  when a filament – a long arching garland of incandescent hydrogen gas – became unstable and erupted. You can see it fly away in the video; it’s the dark streak in the early images.

The aurora often starts early in the evening very low in the northern sky as a pale, arc-shaped glow. Peak activity is usually around midnight-1 a.m.

The sun’s forever blowing bubbles

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A huge bubble of high speed solar wind called a coronal mass ejection or CME leaves the sun at many miles per second yesterday morning July 17. Click photo to see a movie. Photo taken by SOHO’s C3 coronagraph. Credit: NASA’/ESA

Yesterday around 11 o’clock my wife and I were driving to Minneapolis to help move our older daughter. Little did we know that when we stopped to pick up pastries along the highway, the sunspot group that delighted us with auroras last week had just unleashed another significant flare. As we paid the clerk and walked out the door, the coronal mass ejection from the explosion was already ballooning Earth’s way.

Because the bubble is off to one side of the sun and not directly aimed at our planet, the blizzard of electrons and protons will only graze us. A small chance of auroras is possible when it arrives on Friday July 20.

The sky this evening, with the atmosphere removed, so you can see the position of the sun in Gemini and the moon just a few degrees below it. In New Moon phase, we can’t see the moon because it’s too close to sun and invisible in the glare of day. Created with Stellarium

Not far from the sun in the sky a much quieter event is happening. The moon will be in New Moon phase at 11:24 p.m. (CDT) tonight July 18.

If the sun, moon and Earth were exactly lined up in that order, we’d see a total eclipse of the sun, but because the moon’s orbit is tipped relative to Earth’s, it passes a few degrees south of the sun tonight. At other new moons, it passes to the north.

No one gets to see a new moon because it’s much too close to the sun and completely invisible in the solar glare. During a solar eclipse like this past May’s, many of us got to see our first new moon in years as its black silhouette carved the sun into a thick crescent.

Nova Sagittarii #4 photographed on July 16. Thanks and credit to: Bill Gucfa

Nova watchers – not the TV show, but that’s worth watching too – I’ve got good news for you. You can still catch Nova Sagittarii #4 in a small telescope. You might recall that this “new star” was discovered by Japanese amateurs earlier this month in the Teapot constellation Sagittarius.

It’s shining at about magnitude 9.0 and visible in any small scope. You can use the charts from my earlier blog and the photo at left to help you find it. I’ve added magnitudes from the AAVSO (American Assn. of Variable Star Observers) to Bill’s photo if you’d like to estimate the nova’s brightness on your own.