Going on vacation generally means two things for us time-poor city-dwellers: firstly, we’re somewhere where you can actually see the skies away from the usual light pollution and cluttered horizon and, secondly, you have the chance to lay back, drink in hand, relax and stare up at the stars; below are a few ideas for things to watch out for:
Hundreds of shooting stars every minute; that’s hundreds of wishes, right? One of those desires should always be the hope that as Earth crashes through the debris of space, one of those lumps of rock isn’t big enough to make it down to the surface and cause some serious damage. That’s what happened in 1908 in Siberia, the resulting explosion devastated a large section of wilderness – it’s thought that the Tunguska impact was caused by a piece of debris from Comet Encke; meteor storms generally have a parent comet that produces the stream of rocks and ice that hit Earth many times a year. The visibility (and awesomeness) of a particular meteor storm varies from year to year – in part due to how bright the moon is at the time. In 2011 nearly all the major storms occurred when the moon was full but in the next two weeks the Perseid meteor storm should have the skies to themselves as the moon is currently waning. August 12th is the night you should be out watching for this shower of shooting stars – in 2009, up to 160 stars were counted. The Perseids have been observed for thousands of years – they are the debris of the Swift-Tuttle comet, strung out on its 190 year orbit around the sun. This will be one of the more memorable showers this year but there are others – see the earthsky website.
Light pillars, sun dogs and halos
Generally these are more visible in colder climates as they are due to effects of ice-crystals on the light from the sun or moon. A sun pillar is a vertical shaft of light extending upward or downward from the sun. Usually seen during sunrise or sunset, sun pillars form when sunlight reflects off the surfaces of falling ice crystals associated with thin, high-level clouds. Halos can often be seen around the sun and moon and these are truly spectacular, filling up a good proportion of the sky. These are actually quite common – we saw a halo around the moon as few nights ago on a tropical night in Panama. Sometimes around the circumference of the halo, you can see ‘false suns’ or sun dogs – if you’re lucky enough to see something like this, three yellow suns hanging in a blue sky,over a landscape far from home, you might wonder if you’re actually still on planet Earth.
The Green Flash
You might have never even heard of this – or thought it was some fantastical event only visible to crystal-botherers or stoned surfers with water on the brain. Some people think this event was much more common hundreds of years ago, before man-made pollution and the volcanic eruptions of the eighteenth century. But it does, indeed, still happen, every day, somewhere on the planet – if you spend time in the right place watching the sunset, you have a good chance of seeing it too.
The Green Flash is the name given to a range of events which all describe the sun turning green or sending a green ray of light into the sky, just as it sets beyond the horizon. Basically, it is like a mirage – the light from the sun passes through warm air but what’s most important for a successful sighting is that the horizon is far off and flat; looking out over the ocean is the prime situation. The sea should be warm and the atmosphere as clear as can be. The only time I saw one was looking west from the east coast of India on a day that was clear of the usual haze. You’ll find everything you need to know about green flashes here. A green flash can also be blue (much rarer) – the rising or setting moon can also give a red flash (rarer still…).
The Night Sky
Incredible, isn’t it? The same, beautiful display of light that mankind has been gazing up at for all of time. Except, of course, now we have artificial satellites and iridium flares to watch out for these days. There are two things you might want to acquire before you go on vacation – a pair of binoculars and a Star Map for your smartphone, tablet or laptop. Binoculars are much more user friendly than a telescope because you have a wider field of view – their magnification should still be strong enough to see the moons of Jupiter and far-off distant nebulae and you’ll be gazing at the beauty of the full moon for hours – the night sky away from modern cities and other sources of light pollution is awesome to observe just with the naked eye and with a simple pair of binoculars it gets a whole level better… And don’t forget to get a program or app that lets you make sense of what you see. Star gazing software has really revolutionized the activities of the amateur, casual observer: they can be set to your specific location and be able to alert you to astronomical events, reveal the position of planets and show you how to find your star-sign.