Not a post about my Scandinavia trip this time. I’ve slowed down a bit with my trip report because of various reasons I will not blog about (yet). I hope to finish the next few sections (Jotunheimen, Breheimen and Dovrefjell) during the holidays. No, in this post I will look ahead on some spectacular stuff awaiting us in 2013. Two great comets are currently racing into the solar system, and they could put on a spectacular show. This is not an astronomy blog, but still I would like to inform you about these extraordinary events so you can plan your mountain trips next year accordingly. Certainly for photographers this could be a once (or twice) in a lifetime opportunity.
The first comet to watch is named C/2011 L4 (Pan-STARRS). It was discovered in june 2011 with the 1.8m telescope atop of Mount Haleakala as a part of the Pan-STARRS program, which goal is to photograph the entire sky several times a month in search of Earth-approaching comets and asteroids that could pose a danger to our planet. Pan-STARRS will have a 44 million kilometer approach to the sun at perihelion on march 9, 2013. This should be close enough to vaporize cometary ice, resulting in a bright tail. Viewing conditions will be optimal for the northern hemisphere. The comet will race north after the perihelion and become visible low in the western sky immediately after sunset a few days later. Current estimates are that it could become a magnitude 0 to -3 object; or about as bright as the brightest stars and more or less the same as Comet Hale-Bopp in 1997. Pan-STARRS will gradually faint while it moves away from the sun in late march; although it will be higher and higher in the evening sky. I would pick march 11-18 as the best week to go into the mountains and watch the comet. You should pick a location with open view on the western sky. The tail could be short at first, but gradually become longer and brighter as the comet moves away from the sun later during the week. On march 12 and 13 the comet will be very close to the crescent moon, could be a wonderful sight. Some destinations I am thinking of? Looks perfect for winter trips in the (pre-)Alps, the Cordillera Cantabrica or Scandinavia (although the latter obviously has lower chances in terms of clear skies).
But Pan-STARRS is only the warming up for what could become a once-in-a-lifetime comet later in the year. C/2012 S1 ISON was discovered in september 2012 and it soon became clear that this is an exceptional, sun-grazing comet. It will approach the sun as close as 1,8 million kilometers on november 29, 2013. Again, conditions will be optimal for viewers in the northern hemisphere. During the week before the closest approach, ISON will rapidly brighten while it is visibly low in the eastern sky during dawn. On november 29, it will be visible very close to the sun – possibly even during daytime as estimates about its peak brightness range from magnitude -5 (or brighter then Venus) up to magnitude -15 (which is as bright as the full moon!). The day after, it will appear again low in the evening sky in the (south)west at sunset. The tail could become spectaculary long and bright during the first days of december, but the comet will soon start to faint rapidly – although as it moves away from the sun it will remain visible longer after sunset in a darker sky. The best period to watch will be near the perihelion on november 29 and during the first week of december. As this is the dullest period of the year in most of Europe with often difficult conditions in the mountains, one best heads south to watch this comet. I’m thinking of the mountains of southern Spain, the Morrocan Atlas or the Himalayas (although it could be hard to find accessible spots with unobscured views there).
As a final remark – comets are very unpredictible objects, and disappointments have occurred before (e.g. because of desintegration upon approach). Pan-STARRS and certainly ISON could become exceptionally bright comets and in my opinion, it could be well worth planning your holidays accordingly. But again… no guarantees.