Overnight aurora sets sky on fire, more possible tonight

Oct 02, 2013 by Bob King, Universe Today
At around 10 p.m. last night, the northern sky was alive with colorful auroral patches and arcs. Details: 15mm lens at f/2.8, ISO 800 and 25 second exposure. Credit: Bob King

I'm writing this at 1:30 a.m. running on what's powering the sky over northern Minnesota right now – auroral energy. Even at this hour, rays are still sprouting in the southern sky and the entire north is milky blue-white with aurora borealis. Frankly, it's almost impossible to resist going out again for another look.

The arrival of a powerful solar wind in excess of 375 miles per second (600 km/second) from a shocked the Earth's magnetic sheath last night beginning around 9 p.m. CDT. The sun's , embedded in the wind, pointed sharply southward, allowing eager electrons and protons to worm their way past our magnetic defenses and excite the atoms in the upper atmosphere to glow. Voila! Northern lights.

A classic quiet start to Tuesday night’s northern lights – a low green arc below the Big Dipper topped by a very faint red border. Credit: Bob King

Sure, it started innocently enough. A little glow low in the northern sky. But within half an hour the aurora had intensified into a dense bar of light so and green and bright it cast shadows. This bar or swath grew and grew like some atomic amoeba until it swelled beyond the zenith into the . Meanwhile, an isolated patch of aurora glowed like an green ember beneath the Pleiades in the northeastern sky. The camera captured its eerie appearance as well as spectacular curtains of red aurora dancing above the dipper-shaped cluster.

A single patch of aurora glows beneath the Pleiades star cluster at center. Beautiful red rays as seen in the time exposure were only faintly visible with the naked eye. Credit: Bob King

Soft patches, oval glows and multiple arcs lit up the north, east and west, but in the first two hours of the display I never saw a ray or feature with any definition. The camera recorded a few but all was diffuse and pillowy to the eye. Rays finally made their appearance later – after midnight and later – when they massed and surged to the zenith and beyond.

Looks a little scary. A thick wall of green aurora surges upward in the northern sky headed for the zenith. Credit: Bob King

Then came the flickering, flame-like patches and snaky shapes writhing lifelike across the constellation Pegasus during the phase called the coronal aurora. That's when all the curtains and rays gather around the local magnetic zenith. As they flicker and flame, their shapes transform into eagle wings and snakes wriggling across the stars.

A large comet-like auroral form accented with red rays took up residence in the southeastern sky in Cetus from about 10:15 until 11 p.m. last night. around 10:30 p.m. Credit: Bob King

Funny, the space weather forecast called for quiet conditions last night and for the next two nights. But the eruption of a large filament, a tubelike region of dense hydrogen gas held aloft in the sun's atmosphere by magnetic fields, sent a bundle of subatomic joy in Earth's direction a bit earlier than expected. More auroras are possible tonight and tomorrow night as the effect of the shock wave continues. There are so many ways to appreciate the aurora but my favorite is simply to stand there dumbfounded and try to take it all in. Few phenomena in nature are more deeply moving.

It's now 3 a.m. and the won't quit.

Finally – a mighty show of rays around 3 a.m. this morning. What you don’t see in the photo are the rhythmic pulsations fluttering through the entire display, a phenomenon known as “flaming”. Credit: Bob King

Magnetic and auroral activity indicators shot up to high levels last night and this morning. Left image from the POES satellite shows the extent of the auroral oval shortly after midnight CDT. At right, the Kp index shot up to 6 – a G2 or moderate geomagnetic storm – by the early morning. Click to see the current oval. Credit: NOAA


Explore further: Image: Orion crew module at the Neil Armstrong Operations and Checkout Building, Kennedy Space Center

add to favorites email to friend print save as pdf

Related Stories

Night-time view of Aurora

Nov 06, 2012

(Phys.org)—Overnight on October 4-5, 2012, a mass of energetic particles from the atmosphere of the Sun were flung out into space, a phenomenon known as a coronal mass ejection. Three days later, the storm ...

The science behind northern lights

Oct 02, 2012

(Phys.org)—Northern night skies have recently been alive with light. Those shimmering curtains get their start about 93 million miles away, on the sun.

Suomi NPP satellite sees auroras over North America

Oct 10, 2012

(Phys.org)—Overnight on October 4-5, 2012, a mass of energetic particles from the atmosphere of the Sun were flung out into space, a phenomenon known as a coronal mass ejection. Three days later, the storm ...

Venus found to have aurora type magnetotails

Apr 06, 2012

(PhysOrg.com) -- Researchers studying the planet Venus have found that despite a lack of a magnetic field, the planet has magnetotails, which on Earth are part of the process known as the Northern and Southern ...

Beautiful red Aurora

Oct 27, 2011

(PhysOrg.com) -- A coronal mass ejection (CME) shot off the sun late in the evening of October 21 and hit Earth on October 24 at about 2 PM ET. The CME caused strong magnetic field fluctuations near Earth's ...

Recommended for you

Heat testing the miniature Aausat 4 satellite

1 hour ago

The miniature Aausat satellite undergoes repeated temperature variations in a vacuum chamber, cooling the CubeSat to –10°C and heating it to +45°C for more than two weeks. This harsh baptism will make ...

New meteor shower "just a memory" of what once was there

2 hours ago

The weak display of last month's Camelopardalids meteor shower, the result of the close passage of comet 209P/LINEAR, may have disappointed backyard observers, but this never-before-seen shower now has scientists ...

New launch date set for ISS delivery vessel

18 hours ago

A robot ship will be launched from Kourou, French Guiana, after a five-day delay on July 29 to deliver provisions to the International Space Station, space transport firm Arianespace said Tuesday.

The heart of an astronaut, five years on

20 hours ago

The heart of an astronaut is a much-studied thing. Scientists have analyzed its blood flow, rhythms, atrophy and, through journal studies, even matters of the heart. But for the first time, researchers are ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

no fate
5 / 5 (3) Oct 02, 2013
My eyes teared up the one and only time I have seen the Aurura Borealis in person. A truly awesome spectacle, it was overwhelming. I am envious of Mr. King and thank you for the photo's, nice work!
barakn
not rated yet Oct 02, 2013
Tonight's not looking good. The solar wind speed is still high but the density, temperature and magnetic field strength have dropped, plus the magnetic field has a northward component, not south.