What could make a summer weekend even more perfect? How about the northern lights?
The chances of seeing auroral displays are better than usual tonight and Sunday night. That’s due to a geomagnetic storm that’s expected to sweep past Earth this weekend.
The storm was spawned on Thursday by an outburst of electrically charged particles from the sun, known as a coronal mass ejection or CME. The National Oceanic and Atmospheric Administration’s Space Weather Prediction Center says the outburst is directed at Earth, and the peak of the wave should arrive sometime on Sunday.
The most violent outbursts have been known to disrupt satellite communications and power grids, but this one is expected to be merely moderate to strong – producing heightened auroras but no big disruptions.
The big questions are: Can we see the aurora? And if so, where and when?
The answer to the first question is a bit of a crap shoot, depending on space weather as well as good old-fashioned weather in the skies above.
Here are a few websites that provide predictions:Aurora Forecast from the University of Alaska at Fairbanks doesn’t look especially promising for tonight, but that could change as the weekend progresses. The Space Weather Prediction Center provides a more encouraging outlook for the July 16-17 time frame. That time is GMT, which translates to Sunday for PDT types. You can also check the center’s 30-minute and three-day aurora forecasts. SWPC’s Planetary K-Index chart shows expectations for geomagnetic levels. If the K-index is above 5, there’s a good chance an auroral display is in progress somewhere. The Space Weather Enthusiasts Dashboard is a gold mine for geeks. And be sure to check in on SWPC’s Facebook page. Soft Serve News pulls together the SWPC predictions on one webpage and provides the bottom line for the next 45 minutes. SpaceWeather.com rounds up all the news about auroras, eclipses, meteors and other sky extravaganzas – with an aurora photo gallery as well. National Weather Service forecast page for Washington state includes a sky-cover forecast (which looks iffy for the Seattle area overnight).
West Seattle astronomer-educator Alice Enevoldsen put together a fantastic guide for aurora-watching in Western Washington.
The key is to find a place with clear skies to the north, preferably without the glare of city lights. The delicate greenish glow of the northern lights is easily overwhelmed by urban light pollution.
Prime time for summer skywatching generally runs from 11 p.m. to, say, 4 a.m. Here are some of Enevoldsen’s favorite places for watching the skies:
The best way to pick up the auroral glow is with a digital camera set for long exposure. If you can spot the northern lights on your camera’s viewscreen, that’ll help you make it out with your own eyes.
The longer you stay out, the more your eyes become accustomed to the darkness. And of course, there’s lots more to look at in the night sky.
Just after sunset, Mercury sparkles near the western horizon. Jupiter and Saturn light up the evening sky. And in the pre-dawn hours, Venus shines brilliantly with the crescent moon. Check out Sky & Telescope’s viewing guide for the details.
The International Space Station will be shining like a star as well: NASA’s “Spot the Station” website tells you where and when to look.
If you snap a picture of the northern lights, feel free to share it via GeekWire’s Facebook page, and keep an eye on Twitter for #aurora updates from @NWSSeattle, @SkunkBayWeather, @TimDurkan and @TamithaSkov.