It has been many years since a major solar storm lit up the night sky above the Sheboygan Area. For those who remember such events as the great storm of March, 1989, or for those who’ve never seen the display, tonight might be THE night to pay attention for a look at one of nature’s greatest phenomena. The colorful apparition of undulating green, red, and sometimes violet curtains, ribbons and rays, result when immense volumes of material known as plasma is ejected from the sun and interacts with Earth’s magnetic field. Electrons get trapped in the fields magnetic lines, and when those “snap” and disconnect, they shower the electrons down into the ionosphere where mainly oxygen and nitrogen glow like a giant neon light, with detail determined by the sometimes wild shifting of the magnetic lines buffeted by the solar wind.
The Sun as it Appeared on Friday Morning. Sunspot Region-3664 is on the right. Photo by Kevin Zimmermann
A Closeup of Sunspot Region-3664 Which, According to NOAA, is 16-times the Diameter of Earth. Photo by Kevin Zimmermann
The display in 1989 resulted in skies remaining brightly colored after sunset, with the aurora, or northern lights, bright enough to cast shadows for hours. As a downside, the energy disrupted satellite and other communications, caused a 9-hour power outage in Quebec, Canada, and even caused problems with the Space Shuttle Discovery by causing sensor malfunctions. Lessons learned in 1989 have helped develop plans to avoid a repeat of such trouble.
If such an event repeated tonight, the best window would likely be between midnight and 4 a.m. That’s not just prime-time for aurora on the usual basis – which it is – but it’s also expected that the most powerful part of the solar storm will impact earth during those hours. That storm is the result of at least five “coronal mass ejections”. Those bursts of energy were pointed directly at earth when they erupted earlier this week, and originated from a complex of sunspots that’s 16-times the diameter of the earth known as “NOAA region 3664”. It’s so large that it can be safely viewed with your leftover eclipse glasses and appears as a dark dot close to the right-hand limb of the sun. Wherever they’re seen, the aurora benefit from a moonless sky – check that box…it’s a thin crescent that sets around 11:30 – and for local viewers, the initially-cloudy skies of the evening are expected to clear rapidly after 11 p.m., clearing the way for a good view.
The bottom-line question remains, though: “Will we see northern lights tonight?” The Aurora Borealis can be fairly called the poster-child for busting the best forecasts. But this does look promising!
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