Everything begun more or less one week ago, in Montana, during a visit to the Glacier National Park.

One night at the campground, we have been at an even in the parking lot with an astronomer who teach us some basic notions about the night sky. It was not the right night to see the Northern Lights, mostly because there was a big full red moon and the conditions were not good enough.

But he also teach us that every day during the whole year, from a certain latitude and up, is potentially a good one to see the Aurora Borealis. During summer is simply more difficult due to the solar light which takes away a lot of hours and so, often, hides the glare of the Northern Lights. And, even more interesting, the Aurora takes place both during the day and the night, both in summer and in winter, but it is impossible to see it during the day due to the solar light.

Beyond this great news, he also make us aware of the whole lot of satellites crossing the sky over our heads every single second, the famous ISS included.

That night, unluckly, we have not been able to see the Aurora, but two nights ago, coming back from a hike in Banff National Park, it happened. The actual date was August, 9th 2015.

It’s impossible!” I can hear you say so, “Northern Lights can’t be seen during summer!”.

Well, believe it or not, here it is.

northern lights Carstairs (Alberta)

And, finally, the Northern Lights! And the Big Dipper clear on the top left

We were more or less one kilometer from home, in the canola fields, a little hill hiding the light of the city which would blinded us and make the show disappear.

At the beginning, we were driving from Calgary to Carstairs on the highway, a road which goes straight North. A light glare on the horizon, hovering mid-air, right at eye height. It was really faint, as a rising moon but way off the ground.

Then the glare begun to arrange itself into straight shapes, vertical ones and all of a sudden it was clear that we were watching the well known Nothern Lights.

The king astronomer at Glacier Park, Montana, advice us to go on this website, Space Weather (www.spaceweather.com) to find all the informations to understand where and when the Aurora will be visible, updated every three hours.

Let’s give some explanations about the website:

  • More or less mid-page, on the left column, you can find the Current Auroral Oval: this is where it is possible, in the three hours windows between each update, to eventyally see the Northern Lights, if they are visible at the moment.

Current Auroral Oval

Below it, you can see two different index, unintelligible at first sight. Starting from the fact that we still don’t understand well how they work, they are pretty easy to understand:

  • the Planetary K-index (named Kp) consider the intensity of the actual solar storm, which reveal the actual Aurora intensity (quiet means it is slightly visible, with an index of 3, storm means it is really bright, 5 and plus index);

Planetary K-index

  • the Interplanetary Magnetic Field (named Bz) should – for some unknown reason, to us at least – point south to let the Aurora display.

Interplanetary Mag. Field

So, just move north enough, whatever the time of the year, chose a clear night, without moon if possible, and with some luck if you watch towards north, you will enjoy a bright show!

AP

This article is available : Italian

2016-10-13T13:33:44+00:00