The northern lights could put on another show across parts of the United States and Canada this week as a coronal mass ejection (CME) linked to a long-duration M1.4 solar flare heads toward Earth.
uncertain
ejection → put → Earth
NOAA’s Space Weather Prediction Center has issued a G2 (moderate) geomagnetic storm watch for October 9, forecasting G1 (minor) to G2 conditions as the CME reaches Earth.
asserted
CME → issue → Earth
The eruption originated from active region AR4549 on the Sun on October 6.
asserted
eruption → originate → October
The forecast could give skywatchers another opportunity to see the aurora borealis, particularly across northern parts of the US and Canada.
uncertain
forecast → give → US
However, visibility will depend on the strength and timing of the storm, local weather and darkness.
asserted
visibility → depend → storm
CME from M1.4 solar flare heads toward Earth
asserted
CME → head → Earth
The solar activity began with a long-duration M1.4-class flare from AR4549 on October 6.
asserted
activity → begin → October
NOAA's forecast discussion said the flare was accompanied by a Type II radio sweep and a CME first observed in imagery from the Solar and Heliospheric Observatory.
asserted
flare → say → Observatory
The Solar Influences Data Analysis Center said the CME was detected as a faint, almost full-halo eruption and estimated its projected speed at about 560 kilometres per second.
asserted
CME → say → second
The centre said preliminary analysis indicated an Earth-directed component, with an expected arrival on October 9.
asserted
analysis → say → October
NOAA subsequently issued its G2 storm watch, saying G1 to G2 geomagnetic storms were likely on October 9 because of the CME associated with the M1.4 flare.
asserted
storms → issue → flare
When could the northern lights appear?
uncertain
lights → appear → ?
Current forecasts point to the most promising period being overnight Thursday, October 8, into Friday, October 9.
asserted
period → point → Friday
NOAA's forecast indicates geomagnetic activity could begin increasing around 11 p.m. ET Thursday, with conditions potentially reaching G2 levels around 5 a.m. ET Friday.
uncertain
conditions → indicate → ET
The exact arrival time of a CME can change as scientists receive additional solar-wind observations, so the forecast should be treated as a window rather than a guaranteed schedule.
asserted
forecast → change → window
A G1 storm generally favours higher-latitude regions, while a G2 storm can push the auroral oval farther south.
asserted
storm → favour → oval
Which US states could see the aurora?
uncertain
states → see → aurora
Under weaker G1 conditions, the best opportunities are expected across Alaska, Canada and the northern tier of the US, including states such as Washington, Idaho, Montana, North Dakota, South Dakota, Minnesota, Wisconsin, Michigan, Maine, Vermont and New Hampshire.
asserted
opportunities → expect → Washington
If geomagnetic activity reaches G2 levels, the aurora could potentially become visible farther south, with forecasts including areas of Oregon, Wyoming, Nebraska, Iowa, Illinois, Indiana, Ohio, Colorado, Pennsylvania and New York among the possible viewing regions.
uncertain
forecasts → reach → regions
The farther south the auroral oval expands, however, the more important darkness and clear skies become.
asserted
darkness → expand → ?
Why does a solar storm create the northern lights?
asserted
storm → create → lights
The aurora borealis occurs when charged particles from the Sun interact with Earth's magnetic field and upper atmosphere.
asserted
particles → occur → field
As these energetic particles collide with gases in the atmosphere, they transfer energy to atmospheric atoms and molecules.
asserted
they → collide → atoms
When that energy is released, it produces the glowing colours associated with the northern lights.
asserted
it → release → lights
Green is the most commonly observed colour, although stronger displays can produce red, pink, purple and other hues.
asserted
displays → observe → hues
Whether those colours are visible from a particular location depends on the storm's strength, the position of the auroral oval, cloud cover, light pollution and the darkness of the sky.
asserted
are → depend → sky
For anyone hoping to catch the display, the best strategy is to get away from city lights and find a location with a clear view toward the northern horizon.
asserted
strategy → hop → horizon
A dark location is especially important because weaker auroras can be difficult to see with the naked eye even when they are present.
asserted
they → see → eye
Skywatchers should also monitor NOAA's real-time aurora forecasts and local weather conditions before heading outside.
asserted
Skywatchers → monitor → forecasts
The forecast can change as the CME approaches and interacts with Earth's magnetic field.
asserted
CME → change → field
The Weather Network also noted that the timing of the predicted storm could favour parts of Canada, although cloud cover will ultimately determine whether observers can see anything.
uncertain
observers → note → anything
Your smartphone could capture what your eyes miss
You do not need professional photography equipment to photograph the aurora.
uncertain
You → capture → aurora
A smartphone's Night Mode can sometimes capture colours that are difficult to distinguish with the naked eye, particularly during weaker geomagnetic storms.
asserted
that → capture → storms
A tripod or other stable surface can help because night photography often uses longer exposures.
asserted
photography → help → exposures
For cameras with manual controls, increasing exposure time and keeping the device steady can improve the chances of recording faint auroral activity.
asserted
increasing → increase → activity
Still, the most important ingredient is location: a dark sky with a clear northern horizon gives observers the best chance of seeing and photographing the show.
asserted
sky → give → show
For the latest conditions, skywatchers should continue checking NOAA's aurora and space-weather forecasts as the October 8-9 CME encounter approaches.
asserted
encounter → continue → forecasts
The CME's precise arrival and the resulting geomagnetic response remain subject to change.
asserted
arrival → result → change
The Aporia
