Aurora dances across Canada in awesome timelapse. Watch here
Monday, November 9, 2015, 11:55 AM - We've seen some amazing displays of the Northern Lights this past week, but watch the video above, and you'll see one of the strongest solar storms in recent years as it swirls and pulses across Canada.
According to NASA:
The dancing lights in the image above are the aurora borealis or Northern Lights. These auroras are at their most dynamic during geomagnetic storms — often the result of solar storms called coronal mass ejections, or CMEs, that originate from the sun. The aurora shown above occurred as the result of a CME that erupted from the sun early on Mar. 15, 2013. Some 46 hours later, early on Mar. 17, 2013, this CME struck Earth’s magnetic field, depositing and storing energy in Earth’s magnetosphere. When this energy was released, charged particles from the magnetosphere were sent rushing down towards Earth’s atmosphere where they collided with neutral particles, creating the brilliant aurora.
These aurora images were taken from the ground looking up with a network of all-sky cameras spread across Canada, studying auroras in collaboration with NASA’s Time History of Events and Macroscale Interactions during Substorms, or THEMIS, mission. Taking images of aurora from the ground in conjunction with satellite data taken from above the atmosphere gives scientists a more comprehensive picture of how and why the aurora form.
NASA also says that this Canada-wide all-sky camera network has been observing the past week's auroras as well.
While the March 17, 2013 aurora displays were due to the arrival of a large coronal mass ejection - a cloud of charged solar plasma that erupted from the Sun pointed roughly in Earth's direction - the first displays of the Northern Lights that burst across our skies in early November 2015 were actually due to a more constant flow of matter from the sun, known as the solar wind.
As Earth travels around the Sun in its orbit, the planet is caught up in a spinning "pinwheel" of solar particles streaming away from the Sun into space. This "pinwheel" is made up of thick, concentrated streams of the solar wind that move fairly slowly, separated by more diffuse regions that have particle streams moving much faster. Sometimes, though, these faster, more diffuse streams come directly from a region on the Sun called a "coronal hole" - a region where the normally-closed magnetic field loops at the Sun's surface open up, allowing matter to stream away especially quickly. Space weather forecasters call this a "coronal hole high speed stream" or CH HSS.
When a concentrated stream of the solar wind washes over us, Earth passes through relatively untouched as the planet's magnetic field forms a protective "bubble" around us. When we emerge out the other side of a concentrated stream into one of these coronal hole high speed streams, that "bubble" collapses. The fast-moving particles in the stream can then deposit energy into Earth's magnetosphere, just like when a CME sweeps past us. The geomagnetic storms that are sparked by this chain of events typically don't reach the same intensity as the ones touched off by a CME, however they can last longer and the auroral displays can be just as vibrant.