The spring equinox on March 20 means Earth will sync with the solar wind, but it's worth waiting for the Super Worm Moon to wane.

By Jamie Carter
March 20, 2019
Arctic-Images/Getty Images

It's been a good year for the northern lights, with Twitter packed with great photos of the twisting, pulsing green and red polar lights. However, the nights are getting shorter in the Arctic regions and, with the arrival of spring on March 20, aurora hunters in the northern hemisphere tend to pack away their snow boots for the season.

That's a mistake because the spring equinox actually increases the possibility of stronger, more impressive aurora. What's more, the Southern Lights season is about to start in the southern hemisphere, so there's no need to cease the search for the entrancing, dancing spectacle of the aurora.

How does the spring equinox affect the aurora?

Earth revolves on an axis that tilts by 23.5°, and at both the spring and fall equinoxes, our planet's tilt is side-on to the sun. That's important because the cause of the aurora at both poles is the solar wind from the sun, and in March and September that solar wind's magnetic field is in sync with Earth.

It's not an exact science, and more a case of maximizing your chances, but it's always worth planning an aurora hunt towards the end of March. Just pray for clear skies.

Xavier Hoenner Photography/Getty Images

Why avoid the Super Worm Moon?

This year the spring equinox and a full moon dubbed the "Super Worm Moon" both occur on March 20. There's no special significance to that celestial match-up, but it does mean that bright moonlight could blot out the aurora for most of the week. So it's worth delaying a trip to northern latitudes until the last week of March when a less bright moon will be rising much later at night. Although it's worth avoiding the full moon for the very best seeing conditions, the biggest enemy by far on any aurora hunt is cloud cover.

Where to see the Northern Lights

The auroral zone is centered on the Arctic Circle, so get yourself to anywhere between 65°N and 75°N latitude and you should have a good chance of catching the aurora. Alaska, northern Canada, Iceland, and the northern Lapland region that covers Norway, Sweden, and Finland are all reliable destinations.

Where to see the Southern Lights

In the southern hemisphere, the auroral zone is between about 65°S and 75°S latitude. Look on a map and you'll see that there's far less landmass in that region, which is why the southern lights are less observed. The viewing season is the opposite to in the northern hemisphere, stretching from March through September when the nights are longest. Key places to watch the aurora are Tasmania in Australia, Dunedin in New Zealand, the Falkland Islands, and the South Georgia Island, a British Overseas Territory and "gateway to Antarctica." Cruise ships tend to visit in the southern hemisphere's summer from December to March, so it's best to plan a visit as late as possible in March if you want to glimpse the aurora in the night after spending the day penguin and whale-spotting.

Are the Northern and Southern Lights identical?

Apparently not. For many years, scientists assumed so because the poles are connected by magnetic field lines, and auroral displays are caused by charged particles streaming along these field lines. It would make sense that the auroras would be mirror images of each other, but in January 2019 a study by the Birkeland Centre for Space Science in Norway revealed that the solar magnetic field arriving from the sun interacts with the Earth’s magnetic field differently in the north and in the south. Thought to be caused by a magnetic tail that extends away from our planet, a tilt is caused in the Earth’s magnetic field on the nightside of the Earth, causing aurora of different shapes and in different locations in the two polar regions.

How to see the aurora

Get yourself to the auroral zone at the right time of year, and be outside (or near a window, ready to venture out at a moment’s notice) as soon as it's dark. Whatever local people tell you about the time of night the aurora tend to appear, generally ignore that advice because the aurora can, and will, appear at any time of night. Since they're most often observed between sunset and midnight, that is when people tend to be on the lookout, but they can just as easily appear at 3 a.m. An easy way of making sure you see them is to stay in a hotel that offers an aurora wake-up call. Just keep your snow boots by your bed!

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