Tag Archives: coronal hole

Aurora active tonight Oct. 12-13

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A low bank of green auroral rays flickers beneath the Big Dipper early Friday morning Oct. 12, 2012. A similar aurora is out tonight Oct. 12. Photo: Bob King

Just got in from walking the dog and noticed a bow of aurora low in the northern sky. Northern lights also simmered quietly last night late in the north. Tonight’s NOAA space weather forecast predicts possible auroras for the northern U.S. particularly tomorrow night through Sunday morning Oct. 14. The activity originates from a high-speed stream of particles released by a solar coronal hole. If your sky is clear to the north, give a look before you snug down for the night.

More auroras, less dragon spit and an odd shiny object on Mars

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Last night’s aurora simmers beneath the Big Dipper (left). At right is the Kp index chart showing magnetic activity high in Earth’s atmosphere. When the Kp reaches 5, a minor geomagnetic storm with accompanying auroras is in progress. Last night, it shot up to 6 (moderate storm) and stayed there well into the morning. Credit: Bob King (left) and NOAA

First let’s check in on the aurora. Last night’s display continued well into the morning hours. Our sky clouded after 11:30 p.m. but I’m not complaining. The few openings were enough to relish the lively show.

A large coronal hole (dark spot) that may lead to more northern lights. Photographed on Oct. 6 by the Solar Dynamics Observatory. Credit: NASA

Chances look good again tonight and tomorrow night for at least minor storms. While the effects of the coronal mass ejection (CME) are waning, reinforcements are now coming from an Earth-directed coronal hole. The holes or openings in the sun’s otherwise zippered up magnetic field allow charged particles like electrons and protons to escape and stream outward into space at high speed. When they flow past our planet, they can sometimes stimulate auroras. Yes, Earth’s getting a pounding … and we love it! I’ll update later this evening.

How about those Draconid meteors? I never saw any. Few reports from other observers around the world have come in to confirm visually what the Canadian radar recorded yesterday. Evidently the meteors nabbed by radar were too small to leave trails bright enough for the naked eye to see. According to Bill Cooke of NASA’s Meteoroid Environment Office, a  strand of dust shed by the shower’s parent comet Giacobini-Zinner in 1959 was responsible for the sudden and brief jump in meteors.

A photo of Curiosity’s first scoop of soil yesterday also reveals a shiny, possibly metallic object lower in the frame inside the blue circle. Loaded scoop is above center. Credit: NASA/JPL-Caltech

We won’t have to wait long for the next meteor shower, the reliable Orionids brought to us by Halley’s Comet. That one peaks on the mornings of Oct. 20-22. No moon will mar the view.

A cropped version of the picture above showing the object. Credit: NASA/JPL/Caltech

While the Curiosity Rover jitterbugged its first soil sample to make sure the scoop free of Earth contaminants, its cameras spotted a small, shiny object embedded in the Martian soil. It could be metallic and possibly a piece of hardware or even tape that got loose and dropped to the ground. Mission controllers are suspending soil sampling for the time being as they position the rover’s cameras for a better look. We’ll have an update later today especially if it turns out to be a bolt left behind by an early Martian mechanic.

Tomorrow we’ll have times when you can watch the space station link up with the latest Dragon supply ship launched earlier this week by SpaceX.

Mambo borealis – a little bit of green in my life

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The Big Dipper reposes above a low arc of northern lights at 1:30 this morning. While prospects for the aurora are small tonight and tomorrow, activity is expected to pick up again Thursday the 20th. Click photo for a tuneful treat. Photo: Bob King

The north smoldered with a familiar glow last night. A restrained aurora lit up the bottom five degrees of sky a pale lime. Hidden to the eye but revealed in a time exposure, a band of pink haze arched above the visible display.

Space weather forecasters call for a pickup in auroral activity later this week on or about Thursday when gusty solar winds from coronal holes arrive. Let’s hope so. It’s been too quiet around here.

Material from a coronal hole (outlined) streams outward across the solar system. When aimed toward Earth, it can buffet our magnetic field and cause auroras. At right is a graph showing the number of geomagnetic storms (auroras) from 1875 to 1927 compiled by NASA solar physicist David Hathaway. There are clear peaks in March and September-October. Credit: NASA

Fall and spring are usually the best times for northern lights. The orientation of Earth’s magnetic field to the blobs of magnetized material streaming from the sun make it more likely the two will connect. When they do,  solar electrons and protons stream straight into our planet’s magnetic bubble and spark auroras in the upper atmosphere. I’m keeping my fingers crossed. Read more about seasonal auroras HERE.

This map shows the sky 20 minutes after sunset for the northern U.S. Binoculars will show Mars and possibly Saturn. Created with Stellarium

Tonight the 3-day-old crescent moon should be easily visible in the southwestern sky shortly after sunset. If you’d like a fun challenge, see if you can find Mars and Saturn nearby. I doubt most of us will spy them with the naked eye, but binoculars should do the job. Mars will be easier because it’s higher up in a darker sky. Saturn? Could be tricky.

If you’re an early morning person, you can catch plenty of passes of the International Space Station (ISS) this week. The times below are for the Duluth, Minn. region. For times for your town, type in your zip code on Spaceweather’s Satellite Flybys page or log in to Heavens Above. The ISS travels from west to east and looks like a brilliant yellow star.

* Wednesday Sept. 19 starting at 5:13 a.m. Brilliant high pass across the top of Orion
* Thursday Sept. 20 at 6 a.m. Another bright one but this time across the northern sky
* Friday Sept. 21 at 5:13 a.m. Appears out of Earth’s shadow high in the west and then crosses the top of the sky
* Saturday Sept. 22 (First day of fall) at 6 a.m. in the northern sky
* Sunday Sept. 23 at 5:13 a.m. in the northern sky

Aurora alert tonight July 28-29

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The extent of the aurora at 8:30 p.m. (CDT) this evening July 28. The Kp index at the time was 4, just below minor storm level. Click map to see the current index. Credit: NOAA

Be on the lookout for the northern lights tonight (July 28-29). You can even pair up your aurora-gazing with some late-night Delta Aquarid meteor watching . The shower is expected to reach maximum tomorrow morning after moonset when 10-15 meteors per hour could flash from a dark sky.

A high speed solar wind blowing from an open coronal hole in the sun’s atmosphere is presently stoking Earth’s upper atmosphere with an abundance of solar electrons and protons. Looking at the auroral oval map, the northern lights should be visible over Scandinavia tonight if twilight’s not too bright.

While there are no guarantees the activity will continue into the North American night, be on the watch. Any auroras we might get will be more obvious after moonset around 2 a.m. I’ll update later this evening if the lights show up over Duluth, Minn.

** UPDATE 11:30 p.m. (CDT): Pretty cloudy now here, so it’s difficult to tell if aurora is out. I’ve received one report of some faint ones. Auroral oval has shrunk since 10 p.m. and activity’s dropped off a little … for the moment.

Surprise aurora torches the western sky

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Like breath on a mirror, a solitary curtain of northern lights reflects in Spring Lake last night at 11:45 p.m. (CDT). Photo: Bob King

The chances of aurora showing up in northern Minnesota last night were slender, and yet somehow, there it was. There was a small possibility thanks to a stronger than average solar wind streaming from a coronal hole in the sun’s atmosphere or corona. All the usual indicators – Kp index, the satellite photos of the auroral oval – showed low activity.

Before fading away around midnight, the western aurora grew a “tail” that stretched some 30 degrees long. Photo: Bob King

Again by chance, I happened to be observing the sky from the boat landing of a small lake north of Duluth, Minn. Around 11 o’clock I could see a little glow coming from behind tall trees lining the lake’s northern shore. Nothing impressive. But shortly before midnight a most remarkable “torch” of pale green light gradually swelled to brilliance all alone in the western sky.

Before it faded away, the aurora grew a long tail like some giant comet about to strike Earth. 20 minutes later it was gone. Isolated blobs like this one are unusual.

Very faint, diffuse bands of aurora striped the northern sky late into the night. You might still see minor activity tonight from the same coronal hole stream. Take a look at the northern sky before you turn in this evening.

Yesterday I wrote about seeing Comet 96P/Machholz in evening twilight. That’s how I ended up along the lake last night – I needed a good horizon to the northwest to find the comet. If you’ve never set up a telescope on a 25 degree incline 6 feet from dark water you haven’t lived.

A detailed chart of 96P/Comet Machholz’s path tonight through Aug. 2. Click chart for a larger version you can print out. The numbers are the stars’ names, not their magnitudes. Created using Emil Bonnano’s MegaStar program

Mosquitos didn’t make it any easier, but I finally nailed Machholz at 10:30 p.m. It was a small, bright, fuzzy glow through my 15-inch reflector. Like the Soup Nazi on Seinfeld, I suffer for my comets. To lessen your suffering, I’ve made a more detailed chart you can use along with the one from yesterday’s blog. Click it for a larger version.

Saturn and Spica (left) along with Mars, reflect in Spring Lake last night July 24 at the end of dusk. The moon will hover below Mars tonight. Photo: Bob King

I hope you enjoyed watching the moon last night. For the northern U.S., its shallow-angled path meant it was low in the sky and set early. Tonight the moon will be a thicker crescent and make an eye-catching foursome with Mars, Saturn and Spica.

Notice that the colors of Saturn, Spica and Mars are much more obvious reflected in the water than seen “raw” in the sky. I think the water not only expands and softens the images, enriching the colors, but the underexposed reflections are more saturated than the normally exposed stars.

Invisible portals let sun’s wind blow through Earth’s hair

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A coronal hole shows up as huge dark patch in this photo taken this morning in ultraviolet light by NASA’s Solar Dynamics Observatory. Holes are places where the sun’s magnetic field opens up and allows pent up solar wind to escape. Electrons and protons in the wind can cook up auroras in Earth’s upper atmosphere. Credit: NASA

The sun giveth in so many ways. A high speed wind of particles from a large hole in its outer atmosphere is streaming toward Earth right now and will put the squeeze on our planet’s protective magnetic bubble wrap tomorrow June 30 and Sunday.

Flaring sunspot groups currently crossing the sun will also contribute to the disturbance.

That puts at least minor auroral storms back in the forecast, so be on the lookout. One downer. A bright moon could dilute their visibility.

A NASA-funded researcher has been studying a recently discovered phenomenon called “portals” that connect the sun’s magnetic field with Earth’s, allowing the solar wind direct entry to our upper atmosphere, where it can spark auroras and other geomagnetic storm effects.

Earth’s magnetic field lines (pink) tie in directly with the sun’s (yellow) at portals located in the sun-facing side of our planet’s magnetic bubble. The resulting connection sends solar wind particles straight into the upper atmosphere. Credit: NASA

The sun’s magnetic field, which is bundled with the solar wind’s blizzard of electrons and protons, hooks up with Earth’s at so-called X-points, creating an uninterrupted path between our planet and the sun’s atmosphere. Portals are cylinder-shaped and located about 20,000 miles from Earth toward the sun. Approximately every 8 minutes a portal open up and the two fields connect, allowing particles access to Earth. Most X points are small and come and go quickly, but some are as big as the Earth and long-lived.

When Earth’s and the sun’s fields cross at the X point (right) material can follow our planet’s magnetic lines of force (blue) down into the polar atmosphere to create auroras. Credit: NASA

Earth’s magnetosphere staves off much of the sun’s solar wind, but like a mole in the CIA, a portal allows the wind to get in through the front door. Don’t get too alarmed about them – the sun’s wind’s been blowing for billions of years. No matter how it ultimately enters Earth’s inner sanctum to bless and curse us with geomagnetic storms, we’re still protected by our atmosphere from any direct particle hits.

Photograph of the northern auroral oval during an active geomagnetic storm, when Earth’s magnetic field is energized by particles flowing in the solar wind. Credit: NASA

NASA plans to study the portals in detail when the agency with a series of four satellite due to launch in 2014. Called the Magnetospheric Multiscale Mission (MMS), the probes will fan out and hunt for portals using particle detectors and magnetic sensors.

Scientists are coming to understand that the auroras we so enjoy are stoked by more often by the solar wind popping through portals then trickling around the edges of Earth’s magnetosphere. To learn more, take a look at NASA’s video on the topic.

Leaky holes make lovely auroras

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To show quickly the aurora can change, the top photo was taken at 12:31:32 a.m. today; the bottom at 12:32:06 - only 34 seconds apart. The aurora evolved from a quiet to an active rayed arc. Photos: Bob King

A stronger than anticipated impact from material flung from the sun by a large flare in sunspot group 1429 made for lively auroras last night from the northern U.S. and Canada. They never reached high in the sky, but from a location with a good horizon to the north, the many rays that briefly flared around 12:30-1 a.m. were a pleasant surprise.

A huge coronal hole photographed by the Solar Dynamics Observatory in extreme ultraviolet light on March 13. The loopy magnetic fields that normally retard the solar wind have been added. Credit: NASA/SDO

Guess what? We may be in for more with minor auroral storms predicted for higher latitudes (Minnesota maybe?) this evening as a result of the same coronal mass ejection that sparked last night’s display combined with the effects of a large coronal hole that directly faced Earth earlier this week. These “holes” in the sun atmosphere or corona are very interesting phenomena. Normally the tightly looped magnetic fields around sunspot groups constrain the constant wind of particles that blows from the sun called the solar wind. The loops form the same way iron filings arrange themselves around a magnet here on Earth. On the sun, hot gases trace the magnetism that surrounds sunspot groups.

Coronal holes are places on the sun where the magnetic fields stream directly into space unconstrained. They carry ferry away particles into space at speeds around 1.8 million miles per hour – the reason the wind from holes is called the fast solar wind. Because the particles are moving at high speed, they can sometimes make their way past Earth protective magnetic field and spark displays of northern lights high in our atmosphere. Let’s hope we’re so fortunate tonight.

The Apollo 11 lunar module, LRRR (Lunar Ranging RetroReflector), the PSEP (Passive Seismic Experiment Package) and astronauts' footpaths still in place since the day they were made in July 1969. Credit: NASA

Earlier this month NASA released a new, more detailed image from the Lunar Reconnaissance Orbiter of the Apollo 11 moon landing site taken from only 15 miles high. That’s about twice the cruising altitude of a transcontinental air flight. The details revealed are marvelous and include an experiment to measure moonquakes (PSEP) and the retro reflectors that are still used to this day to precisely measure the distance to the moon via lasers shot at the reflectors and received back on Earth.

My favorite are the footpaths in the lunar soil made by astronauts Neil Armstrong and Buzz Aldrin. The mottled gray ground around the module shows they spent most of their time “close to home”, while a single track made by Armstrong leads to the rim of Little West crater 164 feet (50 meters) away.

Thanks in part to discoveries made by on-the-ground investigation and rock collecting by the Apollo astronauts and closeup photos taken by the LRO, we know a lot more about how the moon evolved. Take a look at the short video below. It provides our best explanation to date – without words – of why the moon looks the way it does today.

Solar bling plus auroras possible tomorrow, Tuesday

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The sun photographed in ultraviolet light late yesterday by the Solar Dynamics Observatory displays a beautiful “necklace” of sunspot regions (bright yellow patches) surrounded by loops of hot gas that trace out the powerful magnetic fields above the spots. They’re similar to the arcs formed by sprinkling iron filings around a magnet. Credit: NASA/SDO

A storm is gathering. The good kind, that is. Space weather forecasters at NOAA’s Space Weather Prediction Center expect the effects of a coronal hole on the sun, combined with a recent coronal mass ejection (CME), to fire up possible auroras Monday and Tuesday nights Nov. 28 and 29.  A coronal hole is an open region in the sun’s atmosphere or corona where hot plasma from lower down near the surface can stream away into space. Coronal holes can last for several months and cause repeat auroras approximately every 27 days, when the sun’s rotation brings them into Earth’s line of sight.

This picture was taken at the same time as the top photo but in visible light. The view is similar to what you’d see through an amateur telescope equipped with a safe solar filter. No fewer than seven sunspot groups are in line across the sun’s northern hemisphere. Credit: NASA/SDO

A CME is a large, high-speed burst of solar plasma – a ‘soup’ of electrons and protons bound up in magnetic fields – blasted into space. Many are directed away from the Earth and don’t affect us, but those that are, like the coming blast, can compress our planet’s cushy magnetic bubble and stimulate the production of auroras, affect radio communications and even overload power grids. This particular CME occurred in the wee hours of Saturday morning and is headed our way at nearly 2 million miles per hour.

Since we’ll miss the core of the eruption, only minor storming is forecast for Monday and Tuesday, so I wouldn’t expect a dramatic display of the sun’s muscle. Be on the watch for greenish glows and rays in the northern sky. With the moon still only a crescent, if we do get something, we’ll at least have a dark stage as a backdrop.

With sunrises get later and later as November rolls toward December, you might find yourself up and around during morning twilight. Guess what? That’s just when the International Space Station (ISS) will be making favorable passes over North America in the upcoming week or so. The times below are when to watch for the Duluth, Minn. region. For times for your city, go to Spaceweather Flybys or log in to Heavens Above. Remember that the ISS will appear as a brilliant star, unblinking star traveling from west to east across the sky. It’s currently orbiting 230 miles above our heads.

* Tomorrow Nov. 28 starting at 6:05 a.m. across the northern sky
* Tuesday Nov. 29 at 6:43 a.m. high across the top of the sky and passing near the Handle of the Big Dipper. A brilliant show!
* Wednesday Nov. 30 at 5:49 a.m. in the north and northwest
* Thursday Dec. 1 at 6:27 a.m. high across the south. Another brilliant pass!
* Friday Dec. 2 at 5:32 a.m. Reappears from Earth’s shadow in the Big Dipper high in the northeast and then descends eastward passing the bright star Arcturus
* Saturday Dec. 3 at 6:10 a.m. Another nice, bright pass across the southern sky

(By the way, I want to thank our readers for the inspiration to check out why picture captions were so faint and hard to read. I contacted the blogs management team and explored every internal setting to no avail. Today by pure chance I stumbled upon a well-hidden solution. I hope you’ll enjoy the new legibility.)

Aurora spectacle from outer space

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The Midwestern U.S. at night with a bright display of the aurora borealis over Canada as seen from 220 miles high through a cupola window of the International Space Station. The "Sickle" of Leo the Lion is at top. Click the photo for a larger, unlabeled version. Credit: NASA

Just this week, NASA’s Earth Observatory released a timely photo of the northern lights over the U.S. Midwest and Canada in their weekly e-newsletter. It was photographed by one of the Expedition 29 crew members on board the International Space Station (ISS) on September 29. Grid-like roads and sprawling cities are illuminated by the familiar orange of sodium vapor streetlights, while the aurora is bright enough to make the cloud tops glow green. If you really want to have fun, take a look at this video compiled with multiple still images from the flyover. You’ll feel like you’re flying through space – it’s breathtaking. Since the ISS tracks northeast, the aurora gets closer and closer as the video plays. Give it a minute to load and you won’t be disappointed. I also found a youtube version, but the resolution’s not as good.

Photo taken today by the Solar Dynamics Observatory of the coronal hole that might spark more auroras. Credit:NASA

As for upcoming auroras, there’s a chance for some for the northern U.S. and Canada Friday and Saturday nights as a hole in the sun’s corona or outer atmosphere rotates to face our planet’s direction. Coronal holes are literally holes or openings in the corona where high speed streams of electrons and protons can escape the sun unfettered by the magnetic fields that would otherwise contain them. Some holes can last several months. Every 27-day rotation brings them back in view, giving us a repeat chance for northern lights. In my personal experience, coronal hole auroras are typically “quieter” and less dramatic than what many of you saw two nights ago.

A thick, brilliant band of northern lights crosses Canada and the northern U.S. this past Tuesday evening as recorded by Defense Meteorological Satellite Program's polar orbiting satellite operated by the U.S. Dep't of Defense. It's amazing to see this section of the larger aurora oval expand southward into the states. Credit: Created by Paul McCrone

As long as we touched on the space station, here are some additional times for watching it the next few evenings for the Duluth, Minn. region. For times for your town, log on to Heavens Above or type your zip code in at Spaceweather’s Satellite Flybys site.

* Tonight Oct. 27 starting at 6:14 p.m. in bright twilight across the northern sky moving west to east. Second pass at 7:50 p.m. in the northwest. Watch for the ISS to fade out as it enters Earth’s shadow just below the North Star about three minutes later.
* Friday Oct. 28 at 6:52 p.m. across the northern sky.
* Saturday Oct. 29 at 7:30 p.m. Enters Earth’s shadow and fades away below the familiar W of Cassiopeia. Use binoculars to watch the station’s color change from pale yellow to deep red as it races through another sunset.
* Sunday Oct. 30 at 6:32 p.m. Fades out right next to Jupiter low in the eastern sky about five minutes later.
* Monday Halloween at 7:09 p.m. An ideal time to show the kids while you’re out with them trick-or-treating. The ISS will make a high, brilliant pass across the top of the sky.

Auroras possible tonight through Monday

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Particles streaming from the coronal hole in this photo taken early this morning by the Solar Dynamics Observatory may spark auroras over the northern tier of states the next few nights. Credit: NASA

The latest forecast from the NOAA Space Weather Prediction Center calls for a modest chance for auroras late tonight through Monday May 2 for northern regions. While it’s cloudy here in Duluth, Minn., I hope your weather’s better. If you live in the northern U.S. or southern Canada, take a look outside the next few nights before going to bed. If you see a pale green glow near the northern horizon, it could be the start of a nice display.

As of 8 o’clock this evening, the Kp index, an indicator of magnetic activity around the Earth, is rising. The increase in activity is due to high-speed material streaming from a solar coronal hole toward our planet.