If the clear, cold weather holds, Washingtonians on both sides of the mountains could be in for a rare treat when minor geomagnetic storms set the stage for a view of the Northern Lights on Wednesday night.
The 24-hour watch begins at 4 p.m. Wednesday and lasts through Thursday, according to the National Oceanic and Atmospheric Administration (NOAA) Space Weather Prediction Center. The best chances to see the phenomenon will be between 9 p.m. and 3 a.m. Get away from city lights to the darkest spot you can find, at the highest elevation possible, and then look to the north, low on the horizon, experts at the University of Alaska in Fairbanks advise.
The Aurora Borealis (Northern Lights) and the Aurora Australis (Southern Lights) are the result of electrons from a Coronal Mass Ejection or high-speed solar wind stream colliding with the upper reaches of Earth’s atmosphere, according to NOAA.
The electrons are energized through the acceleration processes that happen in the downwind, or night side, tail of the magnetosphere, the federal agency explains on its website. The accelerated electrons follow the magnetic field of Earth down to the Polar Regions where they collide with oxygen and nitrogen atoms and molecules in Earth’s upper atmosphere.
“In these collisions, the electrons transfer their energy to the atmosphere, thus exciting the atoms and molecules to higher energy states. When they relax back down to lower energy states, they release their energy in the form of light,” said NOAA on its site. “This is similar to how a neon light works.”
Usually, the auroras are most visible over Earth’s north and south poles, but during geomagnetic storms, the field of view expands away from the poles such that the aurora can sometimes be seen over much of the United States, according to NOAA.
Auroras can come in different shapes, including the well-known view that looks like a curtain with folds, according to NOAA, but it can also expand to fill the whole sky.
Early morning auroras, such as the one that could be visible to Seattleites on Thursday morning, can take on a more cloudlike appearance, according to NOAA.
Meanwhile, the so-called Unicorn Meteor Storm, which is expected to bring a brief but spectacular showing of 400 meteors over 15 minutes on Thursday night, will not really be visible in the Western United States, according to Earth Sky. However, people in South America and Western Europe should get a good show.
The meteor shower is known as the Alpha Monocerotids because the meteors radiate from Monoceros, a faint constellation to the left of Orion. Monoceros is Greek for unicorn, according to AccuWeather.