After giving us some of the best meteor showers and moon events of the year, August is closing with its greatest spectacle yet. As Forbes reports, the northern lights will be visible over several northern U.S. states in the lower 48 this weekend, including Maine, Wisconsin, and Michigan.
What causes the northern lights
The National Oceanic and Atmospheric Administration (NOAA) forecasts G1 and G2 geomagnetic storms for August 31 and September 1, 2019. The aurora borealis is caused by solar particles colliding with gas molecules in the atmosphere. As electrons from the sun come in contact with oxygen and nitrogen, they transfer some of their energy to the gases. The colorful ribbons of light we observe from the ground are these molecules calming down and releasing photons into the sky.
Normally the phenomenon is only visible at northernmost latitudes where the Earth's magnetic field, and therefore levels of solar energy, are strongest. But the upcoming geomagnetic storm is expected to hit the Earth with a concentrated dose of solar particles, potentially causing the northern lights to appear farther south than usual.
Where and when to see the northern lights
The first solar storm of the weekend is predicted for Saturday, August 31, and the second is expected to reach Earth on Sunday. If these forecasts are correct, states spanning the U.S.-Canada border are in for a treat. Washington, Idaho, Montana, North Dakota, South Dakota, Minnesota, Wisconsin, Michigan, and Maine all fall within the light show's projected path.
As is the case with any nighttime spectacle, the best time to catch the northern lights is when skies are darkest. That means waiting until late at night or early in the morning to look up, and finding a spot that isn't washed out by light pollution is key. Luckily, the solar storms are following the super new moon on August 30, so skies will be especially dark this weekend.