Probably, everyone has heard of auroras — a relatively rare occasion that turns polar skies into a real light display of green and reddish colours. This beautiful show, aka aurora borealis, happens when molecules from the Sun, hit our planet’s magnetic shield and are best observed up north, which is why these lights are also called polar.

But our planet has a Southern Hemisphere, so does this mean there are Southern lights, too? Yes! The southern light show, Aurora Australis, almost mirrors its better-known counterpart, but not quite. They are neither identical nor precise, mirrored reflections of one another.

Below, describe what causes this peculiar shining, explain the difference between the northern and southern lights, and mention a few spots where you can observe them.

What Causes the Shining & Where It’s Best Seen?

Some layers of the Sun’s atmosphere consist of highly ionised plasma that drives solar particles away from our star. Eventually, this wind ‘crashes’ into our atmosphere, exciting particles of nitrogen and oxygen. They start emitting radiation at visible light spectrums, which, to our eyes, looks like colourful shining in the sky.

Usually, we see red or green hues, which is the shining oxygen. Sometimes, these lights can appear purple, orange, or pink — and these hues are brought on by nitrogen. Technically, northern and southern lights are located in the atmosphere’s upper layers, with green oxygen-powered shining occurring at altitudes of 145-300 km; rarer, reddish glow happens at 300-400 km altitude because that’s where oxygen concentration is lower, and solar ions have to make do with nitrogen instead.

At such altitudes, our eyes are less sensitive to the light show, but that’s not the only reason why reddish shades are less common. They do not occur as often because our atmosphere is not so dense at this altitude, so there are simply fewer ‘collisions.’ That is why purple auroras typically happen at solar maximum, peak times of our star’s activity that occur once per decade and when there are more ions bombarding us from above.

From our land-based perspective, where are the northern and southern lights located? Both occur s, at 60° and 75° latitudes, the northern and southern poles. These regions are also called auroral ovals – that’s where our atmospheric shield is most condensed, so we get to admire the bright collisions as they happen.

What is the difference between North and South Aurora? 

Judging from what causes this shining, there should be little distinction between Northern lights and Southern ones— and, to a certain extent, it’s true. For many years, scientists actually believed that these two are mirrored reflections of one another, with Southern lights occurring from March till September (up North, it’s in reverse). However, careful observations have shown mismatches in aurora patterns primarily caused by asymmetric magnetic field alignments between Earth and the Sun. Simply put, the impact angle is skewered at most times, so the collisions do not occur with the same intensity or in the same spots. This is the primary distinction between North shining and Southern lights— these two are never the same in shade or intensity, and their observation periods differ due to our planet’s rotation axis relative to the Sun.

One more difference becomes clear if have a closer look at the Northern and Southern lights map. In southern areas, shining occurs in less populated regions, if populated at all. So, southern lights visibility is simply better because you are far from city lights and nothing interferes with your view.

So, are the Southern lights better than the Northern lights? In theory, this might well be true, but there is a catch when it comes to practice. There simply aren’t enough places to observe southern night glows because, for the best visibility, you would need to be aboard a ship somewhere in the ocean, closer to the southern pole. Such cruises do exist, but they generally sail in March because that’s when the seas are passable.

Our better-known celestial spectacle, aurora borealis, is way easier to catch because there are plenty of land areas that boast good visibility of this phenomenon. Russian tundra might not be the best choice, of course — even considering its next-to-zero light pollution (or because of it). Scandinavian countries, however, have an excellent tourist infrastructure, with proper roads, public commute routes, and accommodation (not to mention a few other sights any of these countries can offer).

Southern lights, unfortunately, have a rather limited range of observation spots from land. At times of solar maximum, you may see them in some southern parts of Australia and New Zealand, but the best show usually happens in the open seas. Still, this year is, in fact, a solar maximum, so even southern areas are good observation spots. So, our last tip to anyone hoping to see northern and southern lights today is to check forecasts, giving up to 30-minute warnings, on space weather resources, like NOAA or SpaceWeatherLive. And don’t forget your camera! 
Author: Emma Thorpe