Northern Lights To Be Visible in Much of US Due to Powerful Space Weather Condition; How Can G5 Storm Trigger This Cosmic Spectacle?

The natural light display known as aurora is only visible in lower polar regions, typically between 60 and 75 degrees latitude. This means it can only be seen in northern Canada, Iceland, Russia, Finland, Sweden and Norway. In the US, auroras are visible in Alaska since it is located near the Arctic Circle.

Setting the Sky Aglow

In a very rare opportunity, all 50 states, including Hawaii, witnessed the northern lights glowing across the night sky on May 10. In Europe, places as far south as Germany and Spain also caught a glimpse of the stunning celestial phenomenon.

Those who missed the chance to see the auroras can still grab the opportunity to spot this spectacle. Scientists announced that there could be some weak northern lights early this week, although it might be far less impressive than last Friday night's show.

The National Oceanic and Atmospheric Administration (NOAA) has indicated that the coronal mass ejections (CMEs) that caused the big northern light activity this weekend have passed Earth, and nothing more can be expected from them. However, according to Nottingham Trent University astronomy and science communication professor Daniel Brown, another glancing minor blow at G1-G2 can be scheduled on May 13.

Last Friday's display was triggered by a series of CMEs released from the Sun from a particularly volatile sunspot. The sunspot emitted a large number of high-energy solar flares while pointed in the general direction of the Earth. Since this sunspot is about to rotate away from the Earth, our planet will be out of the impact zones for CMEs and solar flares. Any major solar storms observed on Friday will unlikely happen for the next few weeks.

Even if this particular sunspot does not send any more CMEs our way, sunspot activity and space weather are expected to get stronger as we approach the Sun's solar maximum, which is predicted to occur between now and 2026. Those who cannot wait can travel to the northern latitudes with less powerful CMEs, and solar weather can still trigger the auroras. However, they usually are best observed during the winter months.

Rare G5 Storm

NOAA has introduced Space Weather Scales to communicate to the general public the current and future space weather conditions and their possible effects on people. The scales describe the environmental disturbances caused by solar radiation storms, geomagnetic storms, and radio blackouts.

Geomagnetic storms are ranked in terms of their strength on a scale of G1 to G5. Last May 10's disturbance was the first "extreme" geomagnetic storm on Earth since 2003, with a scale of G5.

G5 storms are infrequent, and scientists expect only three to four of these events every 11 years, the duration of an entire solar cycle. According to Queen's University Belfast solar physics professor David Jess, no G5 storm was recorded over the last solar cycle, so this weekend's G5 storms were a reminder of the Sun's power.