A spate of solar activity means that the northern lights may be visible as far south as Oregon, Nebraska and Pennsylvania this weekend.

The aurora may be visible across northern states and some of the lower Midwest to Oregon. But what are the chances for California?

Sky watchers across North America are anxiously anticipating what could be the most intense display of aurora borealis in decades this weekend in the wake of two major solar flares.

Aurora watchers could be in for a treat after the Sun blasted off a huge X-class flare this week. A sunspot region unleashed an X-class solar flare on Thursday (3 Oct), which are the most powerful. NASA’s Solar Dynamics Observatory,

The Sun just unleashed the most powerful flare we've seen in seven years. On October 3, a flare measured at a strength of X9.0 exploded right in the middle of the solar disk. Even more excitingly, it was accompanied by what is known as a halo coronal mass ejection – one that is ejected straight at Earth.