Northern Lights May Be Visible Over Wyoming Tonight

WYOMING — A massive geomagnetic storm that hurled a stream of northern lights-producing plasma toward Earth’s magnetic field has intensified, meaning chances are better that Wyoming will be treated to an ethereal aurora borealis display this week.

The Space Weather Prediction Center, a division of the National Oceanic and Atmospheric Administration, upgraded its geomagnetic storm watch Tuesday, and now says the northern lights displays may be visible to the naked eye across the entire northern tier of U.S. states and as far south as central Iowa on Thursday.

In Wyoming, the northern lights will likely be the most visible Thursday from around 6 p.m. to 9 p.m., and slightly less likely after that until about 3 a.m. Friday.

Some of the farthest-north U.S. states could see the auroras again Friday night as a result of the coronal mass ejection on the sun. The difference in the aurora borealis forecast is the upgrade in the storm from a G2 (moderate) to G3 (strong) level, which can push the aurora far south.

The storm could have a Kp index — a measure of the strength of geomagnetic storms — of up to 7 at its peak. Geomagnetic storm watches are typically issued by the Space Weather Prediction Center for Kp5 and stronger storms. As shown on the map below, northern Wyoming and others above the yellow line may see the northern lights this week.

It’s Prime Aurora Time

If this storm is a bust or you miss the auroras, your chances of seeing the northern lights are greater than ever right now. The reason: Solar Cycle 25. It’s an 11-year cycle in which the sun’s magnetic fields flip polarity, causing solar storms 93 million miles from Earth to occur with much more frequency over the next decade or so.

After solar storms, the auroral oval surrounding geomagnetic poles dips down, explaining why someone in northern Minnesota may see the auroras, but they’re not visible to someone along the same latitude in northern Washington state.

The solar flare Monday was an M4 strength event on a scale of M1 to M9. M-class solar flares are the second-largest type, and are capable of producing some brief radio blackouts in the Earth’s polar regions.

During geomagnetic storms, the ovals expand away from the poles and give some lucky people in the United States an ethereal sky show they’ll never forget. In particularly strong storms, people in latitudes as low as Pennsylvania, Oregon and Iowa can see the lights.

The science behind the auroras — in the Southern Hemisphere, they’re called the aurora australis — is complicated. During solar storms, the sun emits electrically charged ions that move away in a stream of plasma, an ionized gas, known as the “solar wind.” The vivid colors glow when the plasma slams into the Earth’s ionosphere about 60 to 80 miles above the planet’s surface.

As the National Weather Service explains the phenomenon, the lights glow “similarly to how a neon sign lights up when electrons pass through inert gas.”

NASA Rockets To Explore Auroras

Aurora borealis displays are favored in cold-weather regions near the poles, but the energy exchange that causes them is an important source of heat, according to NASA, which has plans to blast two rockets through an active aurora to learn more.

Life on our planet exists in the troposphere, Earth’s lowest atmospheric layer, and the air we breathe is made up of neutral, magnetically balanced atoms and molecules with all their electrons accounted for, NASA explained.

"But hundreds of miles above us, our air begins to fundamentally change character,” the space agency said on its website. “Energized by the Sun’s unfiltered rays, electrons are pried from their atoms, which then take on a positive charge. A once-neutral gas transforms into an electrically reactive state of matter known as plasma.”

The transformation from plasma to neutral gas takes place in an extended atmospheric boundary layer where both intermix. Winds send the particles in different directions, and when they collide, interesting physics results, according to NASA.

“Friction is a great analogy,” Stephen Kaeppler, assistant professor of physics and astronomy at Clemson University in South Carolina, and principal investigator for the NASA mission, said in a blog post on the agency’s website.

“We all know that [if] we rub our hands together, you're going to get heat,” he said. “It’s the same basic idea, except we're dealing with gasses now instead.”

Friction is a constant in the boundary layer where neutral atmosphere and plasma meet, but active auroras intensify everything.

“It’s like storming the football field after a college game,” Kaeppler said. “People at the top of the stadium run towards the field, and as you get closer to the field, the crowd gets thicker and thicker. This is how it is for electrons facing the increasing neutral density of the upper atmosphere.”

The window to launch the rockets in quick succession from Poker Flat Research Range in Alaska opened last week.

So far, conditions haven’t been favorable for the Ion-Neutral Coupling during Active Aurora, or INCAA, mission. Scientists hope to learn how or if the auroras shift the position of the boundary layer where the electrically charged and neutral air.

It could push the boundary layer closer to the ground, raise it higher or even cause it to fold in on itself. Any of the three possibilities could influence how our planet exchanges energy with space around it.

“All of these factors make this an interesting physics problem to examine,” Kaeppler said.