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.

Coronal holes spark auroras Sept. 26-27 — more possible next 2 nights

The aurora around 1 a.m. CDT this morning. Curious forms twisted away in the northern sky in the Big Dipper. Details: 20mm lens, f/2.8, ISO 1600, 20-second exposure. Credit: Bob King

I apologize for not sending an alert earlier, but I was away from the computer and out under the sky tonight. Streams of solar wind from openings in the sun’s magnetic canopy called coronal holes kicked up auroras overnight for the northern states and Canada.

At 9:15 p.m. Friday night the aurora laid low in the northern sky. The arc is the curved border of the auroral oval that’s centered on Earth’s geomagnetic pole. Credit: Bob King

The display began and remained a very low arc from end of twilight until around 11 p.m. CDT when it slowly widened and brightened. The Kp index reached “4″ at that time, not quite a G1 geomagnetic storm but certainly pushing the threshold. Then at 12:20 the arc became brighter and more distinct and split into an exquisite set of short, parallel rays like keys on a piano. Faint rays reached halfway to the zenith as patches of aurora flashed on and off below.

Nice long rays stretch over the forest near Duluth, Minnesota U.S. early this Saturday morning September 27, 2014. Credit: Bob King

While modest, the display was active with a steady supply of rays and pulsating patches, but it never expanded beyond the northern half of the northern sky. Coronal hole effects will linger the next two nights, so be on alert for auroras to appear again.

Check out the aurora! It’s on tonight Sept. 23-24

A fine aurora with many small rays spread across the northern sky around 10 p.m. CDT this evening September 23, 2014. Credit: Bob King

If the sky is clear and you live in the northern U.S. the northern lights are visible right now at 10-10:30 p.m. CDT. Not a huge display, but there’s a broad greenish arc/glow across the northern sky streaked with rays that reach up to the North Star. Very pretty.

A few bright rays below the Bowl and Handle of the Big Dipper at 10:15 p.m. Credit: Bob King

No telling how long it might last, but it’s been out at least since 9:30. No storms, not even minor ones, were in the forecast, but there you have it anyway. The Kp index is currently at “4″ just below minor storm level and the direction of the magnetic field bundled with the solar wind has been tipped south (a good direction for linking up with Earth’s field) for about the past 7 hours. Let’s hope it sticks around!

* Update Weds. September 24 – We’re right on the edge tonight with a chance for a minor display of aurora according to the most recent forecast.

Extent of the auroral oval around 10:30 p.m. CDT shows expansion to the south. Notice the view line brushes the northern states. Click to see current oval. Credit: NOAA

What happened to the aurora? / New forecast for tonight Sept. 13-14

Observers in Maine were treated to a very nice aurora early last night September 12th. Mike Taylor saw this “intense aurora” light up above the unused railroad tracks along Unity Pond at 8:38 p.m. Click to see more of Mike’s work. Credit: Mike Taylor

Feeling disappointed in the aurora last night? The storm happened as forecast only it petered out just about the time the sky was getting dark across much of North America. Observers in Maine caught a good show early, and the lights even put in an appearance here in northern Minnesota, albeit low in the north from behind clouds.

The Kp index, an indicator of magnetic disturbances in Earth’s magnetosphere, shot up to “7″ last night before dropping off to low activity, where it’s remained all day so far today. Credit: NOAA

NOAA space weather forecasters call for minor G1 storm tonight September 13 from about 10 pm to 4 a.m. Central Daylight Time tomorrow.

Minor usually means auroras in the bottom half of the northern sky for skywatchers living in the U.S.-Canada borderland region. You may choose to ignore the forecast and go to bed. I understand. You’re feeling a little burned. Those who feel like soldiering on, remain alert for possible auroras.

ACE orbits ahead of Earth toward the sun and can measure the clouds of plasma belted out by the sun about an hour before they arrive at Earth. Credit: NASA

It’s hard to blame NOAA. Predicting the magnetic inclination of a cloud of solar plasma at a distance is fraught with uncertainty. We get a little help from the Advanced Composition Explorer (ACE) which orbits at the L1 libration point, one of five places near Earth where the sun’s and Earth’s gravity are in balance, allowing a satellite placed there to remain relatively stationary. ACE pivots about some 932,000 miles (1.5 million km) from Earth and 92 million miles (148.5 million km) from the sun.

The probe detects the direction, strength and magnetic field particulars of incoming blasts of particles from the sun and provides advance warning of about one hour of dangerous storms. Storms that affect power grids, satellites and of course paint the sky in northern lights. It also measures the magnetic properties of the cloud and relays that data in real time for us to see in the ACE plots.

ACE plot of magnetic field direction or Bz from last night. You can see how the storm dissipated once the magnetic direction of the cloud changed from south (during the storm) to north (above the white horizontal line). Credit: NASA

Yesterday’s big puff of electrons and protons came packaged in a magnetic field that linked into Earth’s  - at first. But later in the evening, the cloud’s magnetic field changed from south to north and was effectively cut off from connecting with our planet’s magnetic bubble. Earth gave it the cold shoulder, and you and I lost some sleep.

After tonight, calmer conditions are expected for a couple days. After that, it’s anyone’s guess. I’ll be watching tonight and report back.

Showtime! Aurora makes first appearance – updated

A diffuse double is seen low in the northern sky at 9:30 p.m. CDT this evening September 11, 2014. The Big Dipper is off to the left. Credit: Bob King

(Scroll down for the latest update)

Just came in from a check on the northern lights and they’re out. Just a quiet start, but I can see a classic green arc low in the northern sky. Once my eyes were dark adapted, faint rays streaked the sky above the arc. No doubt they would have stood out more boldly were it not for the rising gibbous moon off to the east. Stay tuned for more updates during the night.

Faint rays streak either side of this photo taken at 9:35 p.m. Moonlight lowered the contrast but they were dimly visible with the naked eye. Credit: Bob King

Here are some links for you to check out to help you plan through the night:

The approximate extent of the auroral oval forecast for 10:30 p.m. CDT from Ovation. Credit: NOAA

* Ovation oval – shows the approximate extent of the auroral oval that looks like a cap centered on Earth’s geomagnetic pole. During storms, the oval extends south into the northern U.S. and farther.

* Kp index – indicator of magnetic activity high overhead and updated every three hours. A Kp index of “5″ means the onset of a minor storm; a Kp of “6″, a moderate storm.

* NOAA space weather forecast

* Advanced Composition Explorer (ACE) satellite plots - The magnetic field direction of the arriving wind from the sun. The topmost graph, plotting Bz, is your friend. When it drops into the negative zone that’s good! A prolonged stay at -10 or lower increases the chance of seeing the aurora.

* UPDATE 8:15 a.m. Saturday Sept. 13: Well, well, well. Yes, the effects of the solar blast did arrive and we did experience a G3 storm, only the best part happened before nightfall had settled over the U.S. and southern Canada. The peak was also fairly brief. All those arriving protons and electrons connected for a time with Earth’s magnetic field but then disconnected, leaving us with a weak storm for much of the rest of the night. More activity is expected tonight but the forecast calls for a lesser G1 geomagnetic storm.

* UPDATE 10:30 p.m. : Although the aurora has died back, I just got the NOAA forecast update which still calls for a strong storm overnight. Crossing my fingers it happens.

Graph of Bz from the ACE spacecraft shows the past 24 hours of solar wind direction changes. Far right is 11 p.m. CDT Credit: NOAA

* UPDATE 9:30 p.m. : Definite aurora seen through breaks in the clouds low in the northern sky here in Duluth, Minn. After a big surge late this afternoon and during early evening, activity’s temporarily dropped off. The ACE plot has “gone north”. Will keep tabs and report back.

UPDATE Friday 7:30 p.m September 12: Wow! Kp=7 (G3 storm). Auroras should be visible now over the far eastern seaboard of Canada including New Brunswick and the Gaspe Peninsula. If I were a betting man, folks in Maine should see at least a low, glowing arc in the northern sky. Still dusk here in Duluth.

UPDATE Friday 3 p.m.: The Kp index is now at “5″ or minor storm. If you live in the Scandinavian countries or Iceland, you’re getting a very good show right now.

* UPDATE Friday 9 a.m. September 12: Auroras did appear as forecast overnight beginning at nightfall and continuing through about 1 a.m. this morning. Then the action stopped. The Kp index reached “5″ during that time leading to a G1 or minor geomagnetic storm. It wasn’t a particularly bright aurora, remained low in the northern sky and had to compete with moonlight, so many of you may not have seen it.

The stronger G3 geomagnetic storm from the second and more Earth-directed solar blast is still forecast for tonight. This should bring a much better display and should begin right at nightfall. Peak is expected between 10 p.m. and 1 a.m. Central Daylight Time.

My forecast is good, so I’ll be updating during the night. Good luck and clear skies!

Quiet aurora tonight Aug. 27-28

A lquiet auroral arc topped by a faint pink band glowed softly in the northern sky tonight at 10:30 p.m.. The bright star at right is Capella in the constellation Auriga. Credit: Bob King

After Wednesday morning’s fine display, the current wave of magnetic activity is subsiding but not without leaving a tasty leftover. A low, quiet arc has hovered over the northern horizon all evening. Maybe it will take off again as the aurora did this morning, but the forecast indicates a gradual decline in activity overnight.

Map showing the extent of the auroral oval early this Thursday morning August 28. The arc in the photo above is the edge of the large, permanent oval of aurora centered on Earth’s geomagnetic pole. In this map, which is based on satellite data, you can see that the edge of the oval lies right at Minnesota’s northern border. Click to see the current oval. Credit: NOAA

If you live in in the northern U.S. away from city lights and enjoy the subtle side of nature, you’ll find tonight’s aurora suitable for contemplation.

Beautiful rays of aurora dapple the dawn sky

At 4:45 a.m. CDT this morning (Aug. 27) spectacular rays erupted from a low, bright green arc and paraded across the northern sky. Credit: Bob King

Maybe it’s because of the name aurora, which means ‘dawn’, but that’s exactly when the northern lights put on one great show this morning. With clouds constantly a bother this late summer, many of us have been thwarted in viewing all manner of conjunctions, comets and moonrises. Not this morning. I was determined to see Comet Oukaimeden near Orion just before dawn. And that’s exactly how I happened to be up to catch a surprisingly fine aurora.

A striking green arc perforated by many needle-like rays. Credit: Bob King

One of the keys to maximizing enjoyment of the aurora is to have a place you can get to with a low northern horizon. At least from mid-northern latitudes, lots of activity often occurs very low in the northern sky.

High speed electrons from the sun spiral down individual magnetic field lines in Earth’s magnetic bubble called the magnetosphere to create multiple parallel rays when they strike oxygen and nitrogen atoms in the upper atmosphere. Credit: Bob King

We were already primed for northern lights because of the NOAA space weather forecast, so when I looked out the window at 4 a.m., there they were.

I jumped in the car and sped to a country road not far from home. Arriving around 4:30 a.m. several pale green arcs snaked across the north, and within minutes they erupted with massive parallel rays. To the eye, the tall rays were colorless, but they loved the time exposure afforded them by the camera.

The pictures were taken using a 17mm lens at f/2.8, ISO 800 and exposure times around 15 seconds.

While I did get to see my comet in the nick of time, the northern lights made it more than worth my while. I hope you got to see them, too.

Jupiter (lower left next to the star Delta in Cancer) and Orion (upper right) sparkle in the dawn sky over Duluth, Minn. Wednesday morning. Credit: Bob King

The display continued deep into twilight and no doubt carried into darker skies farther west of my location. There’s still a possibility for minor auroras early tonight. I hope so. Two 4 a.m. stints in a row would kill me.

Surprising aurora puts on great show last night

Auroral arcs are topped by red rays light up the northeast while the moon (0verexposed) and Jupiter shine off to the west in this photo taken last night over a small lake north of Duluth, Minn. Both moon and aurora light are reflected in puddles on the ice. Credit: Bob King

No, it wasn’t in the forecast but just the like real weather, the unexpected happens. A change in the “magnetic direction” of the wind of particles from the sun called the solar wind from north to south made all the difference. Earth’s magnetic field points northward. When the field associated with a batch of plasma from the sun points southward, as it did beginning early yesterday evening, there’s a good chance it will link into our field and ultimately allow those particles passage into our upper atmosphere.

A large red patch briefly glowed above the bright green arc around 11:15 p.m. last night May 3. The color was dimly visible with the naked eye. Credit: Bob King

Spiraling down magnetic field lines like firefighters on a firepoles, billions of tiny solar electrons strike oxygen and nitrogen molecules in the thin air 60-125 miles up. When the excited atoms return back to their normal rest states, they shoot off niblets of green and red light that wash the sky in multicolor arcs and rays.

The whole northern sky lit up with green and red rays earlier this morning. While the green color was easy to see, the red was very pale. The human eye is much more sensitive to green light than red, one of the reasons why the aurora rarely appears red except in a camera during a time exposure. Credit: Bob King

Nothing in the space weather forecast would have led you to believe northern lights were in the offing for mid-latitude skywatchers last night. Maybe a small possibility of a glow very low on the northern horizon. Maybe. Instead we got the full-blown show with auroras of many forms jumping, glowing and dancing all night long. When I finally hit the hay at 4 a.m. flames of moderately bright aurora still rippled across the north.

So what about tonight? Just like last night, there’s only a 5% chance of a minor storm. Like I always say, take a look anyway, because nature always has a surprise or two up her sleeve.

Aurora out tonight May 3-4 over northern U.S.

There may be a lot of trees in this view but they don’t hide the fact that the northern lights are visible tonight right now (10:30 p.m. May 3) low in the northern sky. Take a look if it’s clear by you. Credit: Bob King

(UPDATE May 4: Click HERE to see what a fine show the aurora gave us overnight.)

Watch for auroras tonight. 15 minutes ago, a bright arc lit up in the northern sky here in Duluth, Minn. No way to know if it will fade or go wild, so be sure to take a look if it’s clear tonight. The magnetic field in the solar wind tipped southward this evening, weaseling a connection to Earth’s own magnetic domain and sparking a small display of northern lights. I’m headed back out for more. Good luck – let’s hope it continues.

Chance again tonight April 20-21 for northern lights

Very nice aurora north of Duluth about 10 p.m. Sunday night. The rays were intensely colorful in the camera but much paler to the eye. Credit: Bob King

There’s been some action on the aurora scene today. A coronal mass ejection from the sun blew by Earth this afternoon and sparked auroras over northern Scandinavia and other locations in northern Europe where it was dark at the time. There’s continues to be a fair chance for minor auroras over the northern U.S. tonight (Sun. April 20-21), so you may want to be on the lookout. Check the Ovation Aurora site to see the extent of the aurora in near real time.

Curious crossing of colors – tall pink rays in front of a low green arc.  Amazing! Credit: Bob King

UPDATE 1 a.m. April 21 — The northern lights made a decent showing over northern Minnesota between the end of twilight around 9:30 p.m. until about 10:45 p.m. Sunday night. Lots of slow-moving, “lazy” rays to 50 degrees across the north. Extremely colorful in the camera but pale pink-purple to the naked eye at best. Hope you got to see the show.

Occasional rays formed that glowed for many seconds at a time before fading away appeared in the northern sky. Credit: Bob King