There are towns farther north than Tromsø, but not many. This Norwegian city is located 350 km (about 220 miles) north of the Arctic Circle, though the Arctic cold is moderated by the Gulf Stream. Tromsø is a city of around 60,000 people, and claims the world's most northerly cathedral, symphony orchestra, university and brewery.

If you look up at the night sky in Tromsø, the pole star Polaris is nearly overhead. A few constellations that you're used to seeing at lower latitudes would be missing, and the bright star Sirius is usually too low to be visible. But it isn't the stars that are the main attraction here, it's the aurora borealis - the northern lights. Here is Fredrik Broms's photo of an aurora over Tromsø with a Hurtigruten ship sailing by.

However you can only see the aurora – or the stars – at the right time of year. From mid-April through mid-August, you can't see aurorae, and the only visible star is the Sun. The sky simply doesn't get dark enough to see most celestial sights. In fact, in this part of the “Land of the Midnight Sun” the Sun never drops below the horizon from May 18 to July 26.

Yet if the sky isn't dark enough or the weather is overcast, Tromsø has just the thing to tide you over until another time: the world's most northerly planetarium. The Northern Lights Planetarium was built in 1989 near the university, high on a hill with a splendid view. The one hundred seat planetarium has a full dome ceiling giving 360-degree views.

The planetarium became part of the Nordnorsk Vitensenter (Northern Norway Science Center) in 2002. The center has since added a 2000 square meter (21,500 square feet) building which was opened in 2011. In this picture, you can see the planetarium on the left and the entrance to the new science center to the right. If it doesn't look as though there's 2000 square meters of space there, that's because it's underground.

For summer visitors and those who can't see the northern lights through a cloudy sky, one of the films they might see is Extreme Auroras. It was produced by a local photographer and aurora enthusiast in order to be shown on a dome.

Other films available include ones on the the Sun, development of telescopes, stars, and the origin of life. There are also live presentations, a standard being “The Stars this Month”, which is given only in Norwegian.

I visited the planetarium as part of an astronomy tour with Hurtigruten (the Norwegian coastal shipping line), and we saw an interesting film on what is known about Viking astronomy and an introduction to the night sky as seen by the Sami (also called Lapp, indigenous people of northern Scandinavia).

Here's a drawing of Sami constellations. The large constellation is Sarva, the Moose, which incorporates the classical constellations of Cassiopeia, Perseus, and Auriga. Others are hunting Sarva. Cuoighahaegjek (Castor and Pollux) are on skis hunting the moose, and Galla-bardnek (the three stars of Orion's belt) are the hunting dogs that aid them. There is also an old woman with a pack of six dogs who helps in the hunt. This is Suttjenes-råuko which is classically known as the Pleiades. Fauna davgge (Ursa Major) is a hunter with a bow.

Hands-on exhibits cover a range of science topics, often with an Arctic slant, including energy, climate, environment, the sky above, and others. It's very well laid out and the activities are interesting and some of them quite fun. There's also a cafe and a shop.

NOTE: I visited the planetarium as the guest of Hurtigruten as part of an astronomy tour on which I lectured.