Aurora Australis Lights Up Sky

The swirls, twists, and curtains of light of the aurora australis were visible from the Australian and New Zealand mainland overnight.The natural light display caused a flurry of excitement.

As explained by the Australian Bureau of Meteorology, the phenomenon is caused when electrically charged electrons and protons accelerate down the Earth's magnetic field lines and collide with neutral atoms in the upper atmosphere — usually about 100 kilometers above the Earth.

"These collisions cause the neutral atoms to fluoresce, emitting light at many different wavelengths. The most common aurora colors are red and green, caused by the fluorescence of oxygen atoms, while nitrogen atoms can throw bluish-purple lights into the mix," it said.

The geomagnetic storm, which is just one notch below the highest category of solar storm, began at about 10 a.m. ET on Tuesday, according to the National Oceanic and Atmospheric Administration's (NOAA) Space Weather Prediction Centre. The geomagnetic storm is the result of a pair of coronal mass ejections, or CMEs, that left the Sun on March 15 and are now interacting with Earth's atmosphere and geomagnetic field.

In a press briefing on Tuesday, NOAA scientists said the two CMEs may have unexpectedly combined as they sped toward Earth, which could explain why the geomagnetic storm has been so strong.

References: http://www.smh.com.au/environment/aurora-australis-flares-across-australian-and-new-zealand-skies-20150318-1m290i.html

By: Edwina Owusu-Adjapong.