As Earth's atmosphere absorbs the material from a dead sunspot that shot a ball of plasma, or superheated gas, at Earth earlier this week, medium-sized auroras may spread farther south than usual.
The National Oceanic and Atmospheric Administration has issued a G2 geomagnetic storm alert for Thursday (Apr. 14), with a slightly milder G1 storm watch for Friday (Apr. 15).
Auroras can be seen closer to the equator during geomagnetic storms than under calm conditions, giving skywatchers optimism.
"During such [G2] storms, auroras can seen as far south as, e.g., New York and Idaho - geomagnetic latitude 55 degrees," SpaceWeather.com said in a statement.
The event began with a "dead" sunspot called AR2987. More scientifically, the sunspot had entered a dormant state before erupting abruptly.
According to Philip Judge, a solar physicist at the National Center for Atmospheric Research's High Altitude Observatory, such events occur when convection on the sun splits sunspots apart, leaving magnetically-disturbed areas of the previously peaceful solar surface.
Auroras are associated with coronal mass ejections (CMEs), which are groups of charged particles that erupt from sunspots, frequently following solar flares. When a CME is aimed at Earth, the particles can typically cause auroras in the highest latitudes.
Diverse molecules produce different colors in the northern lights: oxygen produces yellow, green, and red light, while nitrogen produces blue and purplish-red colours.
Strong CMEs can damage satellites, shortwave radio, and power lines, as well as presenting a risk of radiation to astronauts, but this flare appears to be of a more modest kind for the time being.
The sun's 11-year cycle of activity has begun, and we may expect to see more sun spots, flares, and CMEs in the coming years than in past years. CMEs are the most powerful source of charged particles ejected from the sun's upper atmosphere, the corona. Beautiful auroras can be predicted when the sun sends these plasma geysers in the direction of Earth.
The "standard" aurora, which may be seen in the Arctic, is caused by the solar wind, which constantly flows toward Earth. However, geomagnetic storms induced by CMEs can significantly intensify the northern lights and make them visible over much larger areas.
For example, in late October 2021, a massive CME allowed skywatchers in considerably lower latitudes, such as Nevada, South Dakota, Upper Michigan, and New Hampshire, to witness stunning aurora displays. Photographers captured magnificent photographs in Scotland and northern England in the U.K.
