Observers in the northern U.S. and southern Canada should be alert for auroras tonight. The direction of the magnetic field has been mostly south for the past 8 hours, providing a nice linkage into Earth’s magnetic bubble. It’s cloudy in Duluth, Minn., but the Ovation oval plot (above) would indicate visible aurora low in the northern sky from northern MInnesota, Michigan’s Upper Peninsula and northern Maine around 11-11:30 p.m. CDT.
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.
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.
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.
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.
(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.
Here are some links for you to check out to help you plan through the night:
* 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.
* 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.
* 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!
(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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Scandinavians were the lucky ones yesterday when auroras broke out during their nighttime. Here in the U.S. it was still afternoon. Auroras are mighty scarce in sunshine.
Tonight to my surprise, we had a brief display around 11 p.m. CDT. An arc rose above Boulder Lake north of Duluth, Minn., where a group of naturalists and I spent the night at the telescope under a starry sky. At the sight of a few needle-thin rays, one in our group jumped in a canoe and paddled out into the lake for a better view.
Not 15 minutes after it began, the arc and rays faded away, leaving only a faint, diffuse glow until fog settled in around midnight. The Kp index rose slightly during the evening, and the ACE satellite plot has shown a southward pointing Bz or solar magnetic field in Earth’s vicinity for many hours. This is often a good indicator of auroral activity on the way.
The show was subtle but no one was disappointed. Auroras are always welcome around here.
The astronauts are seeing it from the space station. You and I just might too. A G2 moderate auroral storm kicked up this afternoon and early evening, and according to NOAA space weather experts, is expected to continue into the night.
A coronal mass ejection (CME) caused by a filament or plume of hydrogen gas ejected a few days ago caused the sudden surge. The Kp index, a reliable indicator of magnetic activity in Earth’s upper atmosphere hit 6 earlier this evening. Should it ‘stick’ there, skywatchers in Canada and across the northern U.S. stand a good chance of seeing auroras tonight. Look to the north at the onset of night. I’ll keep you posted.
* Update 11 p.m. CDT: The Kp has plummeted to 2! That’s not good. It’s always possible that activity will shoot up again overnight. If you’re out tonight, take a look before going to bed.
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.
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.
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.