This NASA Solar Dynamics Observatory observation shows a composite view of our sun in extreme-ultraviolet light. On Dec. 28, the sunspot cluster AR2473 erupted with a M1.9 flare, sending a coronal mass ejection at Earth.
In recent weeks, the crew on board the International Space Station have been treated to some awesome views of space weather in action. The sun, which has been spluttering out some small to mid-sized flares and coronal mass ejections recently, frequently injects charged particles into our planet's magnetosphere. After being channeled toward high latitudes by Earth's magnetic field, this solar plasma impacts our atmosphere, erupting into a stunning auroral display.What is the Aurora Borealis?
This view from the space station was captured by one of the crew and shows the multicolored streamers of an aurora over the Southern Hemisphere -- known as the Aurora Australis. The different colors correspond to different gases in the atmosphere becoming energized by the solar plasma impacting the atmosphere at high altitudes.
Russian cosmonaut Oleg Artemyevcaptured this eerie photo
of a diffuse aurora over Earth out of one of the space station's windows. The orbiting outpost's solar panels can be seen to the left.
With the space station's robotic Canadarm 2 folded outside the space station, NASA astronaut Reid Wisemanposted this photograph of an aurora to Twitter on Aug. 29
A bright green aurora snakes over the atmosphere below the space station. Green aurorae are caused by lower altitude oxygen atoms in our atmosphere being energized by solar wind electrons.
A burst of beautiful green and red aurorae were spotted on Aug. 19 and NASA astronaut Reid Wisemantweeted this photo with the message
: "Never in my wildest dreams did I imagine this."
The nighttime hemisphere of the Earth is almost dark apart from the ghostly glow of a green aurora.
Often resembling a curtain swaying in the wind, aurorae are strikingly dynamic. They morph into a variety of shapes depending on the quantity of solar plasma hitting the atmosphere and the orientation of the magnetic field.Photographed here by ESA astronaut Alexander Gerst
on Aug. 27, a stunning, curved aurora cuts across the limb of the Earth.
Looking down at Earth during a solar storm, ESA astronaut Alexander Gersttweeted this photo on Sept. 2 with the message
, "This is what we see looking down while being inside an aurora."
The moon sets into an "glowing ocean of green",as described by ESA astronaut Alexander Gerst in a tweet on Sept. 3
. Two Soyuz spacecraft can be seen in the foreground docked to the space station.
You can say what you like about our nearest star, but as this latest solar eruption proves, it certainly has impeccable timing.
On Monday (Dec. 28), a sunspot cluster erupted, blasting an M-class flare directly at Earth. The extreme-ultraviolet radiation immediately washed over our upper atmosphere, initiating an ionization event that caused a radio blackout over South America, Africa and the south Atlantic Ocean. The blackout may have been detected by mariners and ham radio operators in the 20MHz frequency range, according to SpaceWeather.com.
Although the flare certainly wasn’t of the strength of a major X-class flare (the most powerful class of flare), this event did trigger a significant coronal mass ejection (CME) that is currently racing in the direction of Earth. Space weather forecasters predict a direct hit with Earth’s magnetic field on or around New Year’s Eve, potentially sparking some natural fireworks in the upper atmosphere just in time for 2016.
“Sunspot AR2374 has an unstable ‘beta-gamma’ magnetic field that could explode again in the hours ahead,” writes NASA’s Tony Phillips for SpaceWeather.com. “NOAA forecasters estimate a 55 percent chance of additional M-class flares and a 10 percent chance of X-flares on Dec. 28th.”
Flares and CMEs are different beasts triggered by the same magnetic phenomenon. During periods of high magnetic activity on the sun, the sun’s internal magnetic field forces its way through the sun’s photosphere (colloquially known as the sun’s “surface”). This magnetism exposes the inner sun, which is counter-intuitively cooler (and therefore appears darker) than the sun’s chromosphere (the layer of atmosphere above the photosphere) and corona (the sun’s extended and multi-million degree atmosphere). Therefore, magnetically active regions can be easily seen on the sun’s disk as spots and clusters of dark spots known as “sunspots.”
As the magnetic field lines become forced together above these sunspots, magnetic reconnection may occur, accelerating solar plasma to relativistic speeds, generating intense bursts of radiation. These are solar flares and their radiation reaches Earth in minutes. However, CME’s are bubbles of magnetized high-energy plasma that are ejected into space at high speed, but nowhere near relativistic speeds. CMEs can reach Earth in several hours or a few days, depending on the ferocity of the eruption.
And today’s flare and CME happened to be generated by the same sunspot that was Earth-directed, maximizing our chances of having a geomagnetic storm right in time for New Year’s. So if you live in high latitudes, and pay attention to the sky, you may be in for a New Year treat as high-energy solar particles impact our atmospheric gases, generating bright aurora.