Auroras May Hit Northern U.S. States This Week Due to Geomagnetic Storm

Solar activity may cause the northern lights to appear over northern U.S. states on Wednesday and Thursday when Earth is dealt a blow by a cloud of plasma.

The plasma cloud is known as a coronal mass ejection (CME), and it was launched from the sun Sunday. Since then, the cloud of charged gas has been traveling toward Earth at high speed.

On Monday, the U.S. National Oceanic and Atmospheric Administration's (NOAA) Space Weather Prediction Center (SWPC) said on its website that G1 (minor) and G2 (moderate) storm watches were in place for Wednesday and Thursday respectively after Sunday's CME was detected.

Northern lights
A stock image of the Northern Lights. The popular night sky phenomenon occurs due to solar particles hitting Earth's atmosphere. marouan touil/Getty

The SWPC said the cloud of charged gas is "expected to arrive at Earth as a glancing blow" on Thursday and that auroras "might be seen over the far Northeast, to the far upper Midwest, across portions of the north-central states, and perhaps over the northwest section of Washington state."

CMEs are relatively common and often ejected from active regions of the sun where intense magnetic field lines are tangled and contorted. When these magnetic field lines suddenly shift, vast amounts of energy are released in the form of radiation and plasma.

Earth isn't always in the path of CMEs. But when it is, these clouds of charged gas can disrupt our planet's magnetic field and potentially cause issues with some modern technology—though most people will not experience any noticeable changes with moderate-strength CMEs.

For example, CMEs can cause the upper atmosphere to heat up, leading to increased drag on satellites operating in low-Earth orbit—potentially leading to their destruction. Other possible CME effects include power grid fluctuations and disruption to radio communications.

These disruptions are known as geomagnetic storms, and they are measured in strength from G1 to G5, with G5 being the strongest.

While CMEs can cause some issues, they can also cause stunning auroras. Auroras happen due to the interaction of solar particles with Earth's magnetic field. And since CMEs can cause large magnetic disturbances, they can trigger the northern lights at much lower latitudes than usual.

For Wednesday and Thursday, the SWPC states auroras might be seen "as low as New York to Wisconsin to Washington state"—though this will likely depend on how strong the CME ends up being. In addition, it may not be possible to view the auroras due to cloud cover, light pollution, or if they don't occur at night. Details on exact timings were not provided by the SWPC.

Newsweek has previously outlined some tips on aurora photography for anyone who is keen to catch them on camera.