In April 2015 I travelled to Macquarie Island on the Aurora Australis, the research vessel named after the atmospheric phenomenon. Auroras occur when solar winds interact with the Earth’s magnetic field and are most common around the equinoxes. Auroras were seen on several nights during the two week science and resupply mission to Tasmania’s subantarctic outpost, 1500 km south-east of Hobart.
On our second night on the island we reached a small ‘googie – field hut field hut late in the afternoon, shortly before the cold southerly airflow brought a rapid dusting of snow down to sea level. A couple of hours later, after dark, the clouds cleared and the air was unusually still. The sky was filled with swirling white beams and shimmering curtains of otherworldly neon green. Having previously only seen a couple of faint auroras in Tasmania I was unprepared for the intensity and dynamism of this display.
Auroras are most often seen in polar regions because they occur in an ellipse around the magnetic poles of the Earth. At mid-latitudes, such as in Tasmania (40-42°S), the Aurora Australis is therefore seen in the southern sky. But at higher latitudes such as Macquarie Island (54°S) you can be south of the aurora, depending on how far north it happens to extend. So it was strange to see the ‘Southern Lights’ in the northern sky! At Brothers Point on the east coast of the island a large beam extended overhead from behind Mount Tulloch to the west to near the eastern horizon over the ocean. It frequently played across the northern sky over Sandy Bay, but was not visible in the south.
At its brightest it was similar to the light of a full moon, illuminating the fresh snow in an eerie way. After an hour or so of watching the aurora ebb and flow another snow squall approached from the south and it was over. All of these images are 30 second exposures so they are slightly more blurred and more colourful than what is visible to the eye.