Earth’s Greatest Light Show: Exploring the Auroras & the Solar Storms That Create Them
The aurora borealis and its southern counterpart, aurora australis, are one of the most beautiful light shows in nature. Dazzling those lucky enough to catch a glimpse of its captivating shimmer, the aurora is Earth’s greatest light show.
These colorful displays of light are caused by activity on the sun — particularly a type of solar storm called a coronal mass ejection (CME), which emits electrified gas and particles into space. It takes around three days for electrified particles to reach magnetic field lines at the north and south poles and enter Earth's atmosphere.
Particles and energy, upon arriving in the atmosphere, interact with gases there, causing an array of hues to appear in the sky. Aurora Watch at Lancaster University in the United Kingdom has reported that oxygen emits green as well as red light, the latter being the more commonly seen color. NASA states that nitrogen emits a blue and purple glow.
Photographers and night sky watchers have been capturing the colorful display further south (or north if you’re in the southern hemisphere) than usual — places like the state of Colorado, the southeast of England and New South Wales. The pilots of the planes have flown in a circular motion mid-flight to allow their passengers to have a better view of the phenomenon.
Researchers at NASA’s Solar Dynamics Observatory said they detected two M-class solar flares on Friday and Saturday that led to CMEs, triggering the recent bout of elevated geomagnetic activity and producing the captivating auroras. According to NASA, flares from the Sun are classified in order of size, starting with the smallest A-class, followed by B, C, M and the largest, X.
On Tuesday, EarthSky reported that a solar flare erupted that was just below “X-class,” but there was no coronal mass ejection (CME). AR3234, a sun spot region described as “large and magnetically complex”, has caused a recent increase in geomagnetic activity, according to the Met Office of the United Kingdom.
Fluctuations in flare activity occur during the 11-year solar cycle of the sun. The latest solar cycle, Cycle 25, commenced in December 2019, when the sun entered a solar minimum state; a time when activity is reduced and sunspots are fewer.
0. “Why the northern and southern lights appear to be so active right now” NBC Palm Springs, 1 Mar. 2023, https://nbcpalmsprings.com/2023/03/01/why-the-northern-and-southern-lights-appear-to-be-so-active-right-now/
1. “Why the northern and southern lights appear to be so active right now” ABC 57 News, 3 Mar. 2023, https://www.abc57.com/news/why-the-northern-and-southern-lights-appear-to-be-so-active-right-now
2. “Why the northern and southern lights appear to be so active right now” CBS News, 1 Mar. 2023, https://www.cbsnews.com/detroit/news/why-the-northern-and-southern-lights-appear-to-be-so-active-right-now/