Aurora Predicted Tonight But Will We See It?

The sun ejected a thin cloud of plasma (a hot dilute gas made of electrons and protons) toward Earth on Oct. 9. To see it clearly, I increased the contrast in a photo taken by the Solar and Heliospheric Observatory's C2 coronagraph, a device that masks the sun. Credit: NASA/ESA
The sun ejected a thin cloud of plasma (a hot dilute gas made of electrons and protons) toward Earth on Oct. 9. To see it clearly, I increased the contrast in this photo taken by the Solar and Heliospheric Observatory’s C2 coronagraph, a device that covers the sun, represented by the white circle. Click the photo to see a video of the blast. Credit: NASA/ESA

A potentially bright aurora is in the forecast this evening (Oct. 13). The sun shot a CME or coronal mass ejection almost directly toward the Earth in the early morning hours of Oct. 9. After a journey of 93 million miles, the busy cloud of electrons and protons is expected to arrive this afternoon and rile our planet’s magnetic field. The peak of activity happens at just the right time for skywatchers across the central and eastern U.S. and Canada. Between about 7 and 10 p.m. Central Daylight Time, we’re expecting a G2 or moderate geomagnetic storm. That could bring the northern lights into view as far south as New York and Idaho.

A large, multi-part coronal hole, where material streams freely from the sun into space, will also pump up our chances of aurora again on Saturday night Oct. 15. This photo was taken in ultraviolet light by NASA's Solar Dynamics Observatory earlier this morning. Credit: NASA/SDO
A large, multi-part coronal hole, where material streams freely from the sun into space, will also pump up our chances of aurora again on Saturday night Oct. 15. This photo was taken in ultraviolet light by NASA’s Solar Dynamics Observatory earlier this morning. Credit: NASA/SDO

But will we see them? Given a dark sky, chances are good, but tonight the moon is waxing gibbous just three days before full. It could brighten the sky enough to wash out a modest display of the aurora. We’ll just have to go out and see. Tonight’s forecast for my city is clear, so I’ll keep tabs and send out a tweet if we get a nice show.

* UPDATE 10:15 p.m.: A strong geomagnetic storm (Kp=7) got underway late this afternoon and early evening with widespread auroras visible from the northern states and Canada. As of 10 p.m. CDT, the index has dropped some, but if the sky is clear and you live in the northern U.S. and southern Canada, there’s a good chance the aurora’s still in view. It definitely bested the moonlight!