Purple, pink and green.
The Northern Lights were a total surprise over states like Wisconsin, Michigan and Minnesota during the first weekend of April 2011.
A surprise because space weather forecasters are still trying to figure out the Northern Lights, particularly those caused by weaker ‘storms’ like the ones this weekend.
A NASA article written by Dr. Tony Phillips put it this way:
“There’s a great deal we don’t understand about auroras,” says UCLA space physicist Vassilis Angelopoulos. For instance, “Auroras sometimes erupt with little warning and surprising intensity. We call these events ‘sub-storms,’ and they are a big mystery.” What triggers the eruptions? Where is sub-storm energy stored? (It has to gather somewhere waiting to power the outburst.)
The odds of seeing the Northern Lights over Washington and Oregon should be increasing over the next few years. The sun is expected to become more active with a growing number of sun spots and solar eruptions. Solar eruptions aimed at earth are the main cause of the auroras. So keep your fingers crossed.
But let’s hope the solar storms don’t get too big. NASA’s take:
Auroras are much more than just pretty lights in the sky. Underlying each display is a potent geomagnetic storm with possible side-effects ranging from satellite malfunctions in orbit to power outages on earth. Telecommunications, air traffic, power grids and GPS systems are all vulnerable. In a society that relies increasingly on space technology, understanding these storms is vital.
NASA satellites have studied auroras so we have a better idea of what’s going on. But there’s much more to learn.
In the meantime, here’s the Northern Lights Gallery for April 2011. There are already some awesome shots!