Get ready for a spectacular display of auroras across the northern United States tonight! A strong G3-class geomagnetic storm is crackling through Earth’s atmosphere, making it possible to spot vibrant auroras as far south as Oregon and Pennsylvania. However, the nearly full Harvest Moon may complicate viewing opportunities.
According to NOAA’s Space Weather Prediction Center, the auroras could be visible in many states along the U.S.-Canada border tonight. The presence of the moon overhead may make it harder to spot the colorful displays than it would on a truly dark night.
Geomagnetic storms occur when massive blobs of charged solar material pass over Earth at high speeds, colliding with our planet’s magnetic field. As charged particles skate along the planet’s magnetic-field lines toward the North and South poles, they bump into and excite atmospheric molecules, forcing them to emit energy in the form of colorful auroral light.
To view the auroras, head as far from artificial light sources as possible, using a dark sky map if needed. With a little luck, you can capture the atmospheric light show with your smartphone camera or spot it with your naked eye.
Source: https://www.livescience.com/space/the-sun/auroras-may-paint-the-northern-us-tonight-as-earth-reels-from-strong-g3-geomagnetic-storm