Northern Lights may shine across much of Canada late Tuesday night
A solar storm erupted from the surface of the Sun over the weekend, aimed more or less directly at Earth.
Turn your eyes to the northern sky overnight on Tuesday night. We may see the Aurora Borealis across Canada due to a solar storm sweeping past Earth.
In the evening on Sunday, July 21, an immense 'halo CME' erupted from the Sun. So-called because, to the NASA/ESA Solar and Heliospheric Observatory (SOHO), it appears to surround the Sun as it expands into space, this coronal mass ejection is on a trajectory towards Earth.
Currently forecast to arrive in the early hours of Wednesday, July 24, when it does, this cloud of charged solar plasma may cause a disturbance in Earth's magnetic field known as a geomagnetic storm.
Forecasters with NOAA's Space Weather Prediction Center have issued a G2 geomagnetic storm watch for the hours after midnight on Tuesday night into Wednesday morning.
Depending on the impact of this solar storm, it could spark bright displays of the Northern Lights across Canada and some northern regions of the United States.
The G2 geomagnetic storm watch, issued on Monday, July 22, showing the beginning of the halo CME (top left), and the timing of when this solar storm will arrive at Earth (bottom centre). (NOAA SWPC)
According to NOAA SWPC, this will most likely happen between the hours of 6 UTC and 9 UTC (2 a.m. to 5 a.m. EDT, or 11 p.m. to 2 a.m. PDT).
Given that aurora activity tend to be strongest for locations that are directly opposite to the Sun during the geomagnetic storm, western Canada may have the best timing for this event.
The above map plots the southernmost visibility of the auroras based on the geomagnetic storm strength (G1-G5) and their corresponding Planetary K-index (Kp) value (Kp 3 through 9). For Wednesday morning's G2 geomagnetic storm, auroras could be visible between the green and yellow lines.
If you miss this opportunity, there is the potential for more, due to another CME erupting from the Sun's southeastern limb on Monday.
Unlike Sunday's halo CME, this new solar storm does not appear to be aimed directly at Earth. However, a portion of the plasma cloud could still have an impact on us.
These five frames from SOHO's LASCO coronagraph show the expansion of this new CME away from the Sun (bottom left) on Monday, July 22. (NASA/ESA SOHO)
The exact effects of it will depend on how fast it is travelling, how dense the cloud is, and how much energy the particles in the cloud are carrying. If it manages to catch up to the halo CME before arriving here, or instead arrives on its own shortly after the halo CME, its impacts could even add to those expected on Wednesday morning.
Tuesday Update
As shown above, Monday evening's CME that erupted from the southeast limb of the Sun was pretty spectacular. Shortly thereafter it was also followed by a bright, full halo CME that accelerated very quickly away from the Sun's surface.
These two composite views of the CMEs on July 22 and July 23 combine coronagraph images from the Solar and Heliospheric Observatory taken at roughly the same time, along with extreme UV views of the Sun from the Solar Dynamics Observatory. (NASA/ESA, NASA SDO, Scott Sutherland)
Unfortunately, though — at least for aurora enthusiasts — it appears as though both of these solar storms erupted from the far side of the Sun. Tuesday morning's event managed to bombard Earth with solar protons, causing a minor solar radiation storm, but that is likely to be the full extent of impacts to Earth from these CMEs.
However, we are already seeing indications of some very active Active Regions swinging around the eastern limb of the Sun.
Active regions 3763 and 3764, on the eastern limb (left edge) of the Sun, show up bright in this combined view from the Solar Dynamics Observatory, with many overlapping coronal loops. In the background, beneath AR 3763/3764, is where Monday night's CME erupted, indicating the presence of another active region there. Active regions are areas on the Sun with tangled magnetic fields, which show up as dark sunspots and sunspot groups on the surface. An image of the Earth is provided (bottom left corner) for scale. (NASA SDO/Helioviewer.org)
The bright area shown along the left edge of the Sun in the image above is a combination of two different active sunspot groups. However, those appear to be just a prelude of what is coming. The active region responsible for Monday evening's CME is located to the south of AR 3763/3764 and still just beyond our view. It should be rotating into view a few days from now.
The active region that produced the immense halo CME from Tuesday morning would appear to be on the exact opposite side of the Sun from us. With the Sun taking 27 days to complete a full rotation, we should see the region that produced that bright CME in about a week.
(Thumbnail image courtesy Dennis Mersereau, who captured the auroras on the night of May 10, 2024 from North Carolina)
