Elusive lure of the Northern Lights
It's fair to say that the Northern Lights are pretty high up on many people's lists of things to do before they die.
However, the big problem, like any naturally occurring phenomenon, is actually making sure you see them.
It's not just as easy as booking a trip, travelling to somewhere like Norway and looking to the skies.
For starters, the lights can only be seen for a few months a year; and secondly, you are at the mercy of the weather.
More and more people are finding a way of "cheating", by taking specially chartered flights.
These types of "science tourism" flights have been around since the late 1990's, but have grown in popularity in recent years - thanks in part to recent interest from the media.
I joined a group on one of these flights, from Humberside Airport in north-eastern England. The flight was the first of this kind for the airport and was a sell out.
The idea behind it is to cheat the weather, by flying above the clouds to give an 80% chance of seeing the Aurora.
With odds like that, the chances are you will get to see them; but it is all down to the "space weather" on the day, so no guarantees are made by the company behind the trips.
Before taking off for a three hour flight - which depending on the forecast can head as far north as Icelandic airspace - you are briefed by a team of astronomers about what you might see.
Apart from seeing the lights, being above the clouds and away from light pollution gives you a great view of the night sky, and the team briefs you on what else you may see.
Before taking off the forecast looks fairly good - a coronal hole in the sun is facing the Earth, meaning the chances of seeing the Aurora are good over the next few days.
The plane used is just a normal jet, with rows of three seats on each side. The idea is that once in the air you need to move around seats, so that everyone can get a look out of the window.
Once in the air, all cabin lights are turned off. To allow your eyes to adjust to the darkness, this is done for the 40 minutes before we arrive at the best place to see the display.
On my flight, the pilot was also able to turn off the wing lights - although this is not possible on every trip.
The idea of flying is that you can travel to the best possible place to see the display - which, in the case of this flight, was to the far north of Scotland.
Once in place and in complete cabin darkness, the hunt then begins for the lights.
Unfortunately, this trip was not as successful as it could have been.
Yes, the lights were visible - but as a thin glow of grey/green above the horizon, not the large green glow that you can get on much stronger displays.
Another thing to bear in mind when thinking about an airborne excursion is that you are viewing the display over a much wider area, and unlike on the ground, it will not take up the whole sky.
The reason for the lack of display... well, there are many, but the most likely one for this trip was that despite the good forecast, we were there too soon.
The displays seen on similar flights later that week were much stronger.
This type of trip has grown in popularity over recent years.
Between 25 and 30 flights just to see the Northern Lights have been put on this year, with many more companies offering specific holidays just to see the display; and with the last transit of Venus for more than a century coming next year, there is already demand for flights to view the event from the air.