Comet Observing

So, a pair of bright comets are on their way… we hope! How do you observe them?

It all depends how bright they get, and we can’t predict that yet. Lots of people are claiming ISON will be dazzlingly bright, but anything could happen. So let’s have a quick “Comets Guide”…

* Comets are basically big, dirty icebergs/snowballs, leftovers from the birth of the solar system.

* Most of the time they are a long, long way from the Sun, and very hard to see. Only when a comet comes closer to the Sun, and “turns on” in its heat and light, do we see it shine in the sky.

* Although naked eye comets are quite rare, there are at least half a dozen comets in the sky on any night of the year, but they’re so faint they need a telescope to see them, and even then they only appear as tiny, fuzzy balls in the eyepiece, no matter how much you magnify them…

* Comets do move across the sky, but they don’t FLASH across the sky. That’s what shooting stars or fireballs do. Comets move very slowly across the sky, their movement only really noticeable from night to night, or even week to week if the’re a long way away. If a comet comes particularly close to the Earth you can sense their movement by looking at them for an hour or so, and noticing how they’ve moved through the starfield. But comets do NOT dash across the sky. And no matter what The Waterboys say in their song, they don’t “blaze a trail”.

* A naked eye comet can, as its name suggests, be seen with just the naked eye, but most naked eye comets never get much more impressive than a small, round smudge of light in the sky, with no tail, or just a very short, stubby tail which makes them look like blur of light in the sky. These need to be seen through a pair of binoculars to be enjoyed properly.

* Occasionally a brighter comet comes along, with a more impressive tail several or many degrees long (what does THAT mean? Well, the Moon spans half a degree in the sky, so if a comet has a til that’s ten degrees long it’s as long as twenty Moons in a line) which is obvious to the naked eye. These are very attractive and they’re lovely to watch as they hang above the horizon, usually before sunrise or after sunset…

Again, binoculars make them more obvious, and they allow you to see subtle details in the tail – kinks, streamers, clumps and knots of cometary material – that the naked eye can’t pick up. And if you look at them through a telescope you can see sometimes subtle structure in and around the comet’s glowing head, too – jets, shells, and spikes…

* Very occasionally a BRIGHT naked eye comet appears, a so-called Great Comet, and then it all goes a bit nuts! When Hale-Bopp was in the sky in 1997 it was seen by many thouands of people every night, all around the world, and from here in the UK it was a wonderful sight in the west after sunset, its twin tails making a lovely “V” of light, one side blue, the other side creamy yellow/grey. It was visible even from the middle of towns and cities and was a remarkable sight from a dark location…

When a Great Comet appears you just have to make every effort to see it as often as possible, with your eyes, through binoculars and a telescope.

* Bright comets are great photographic subjects, too. Back in the prehistoric, pre-digital Hale-Bopp days, comet and night sky photography was an expensive and frustrating business. We used those old-fashioned “film” cameras, and that meant often using up a whole roll of expensive film and getting back only a couple of decent images! I must have taken hundreds of pictures of Hale-Bopp, and only kept a few dozen of the slides. But now, digital cameras mean you can click away all night, taking thousands of images, changing exposure and aperture settings, just experimenting, and not waste a penny! You young ‘uns don’t even know you’re born! So, if either PANSTARRS or ISON becomes a really bright comet, even simple digital cameras should be able to take perfectly good pictures  – and digital SLRs will take beautiful pictures.

I’ll post some comet photography tips nearer March.

PREPARING FOR PANSTARRS AND ISON

In any other year, Comet PANSTARRS, due in March, would be a real headline-maker, but with Comet ISON due to (hopefully!) dazzle us much more later in the year, poor PANSTARRS is going to be a “dress rehearsal” for the main act. But we should think of this as a good thing, in fact a  golden opportunity to practice comet observing and photography so we all are as prepared as possible for ISON when it appears next Winter.

So, to prepare for PANSTARRS (And ISON)  I strongly suggest you do the following NOW…

1) Look at the finder charts on this blog, and use them to work out where Comet PANSTARRS will be in your sky come March, and ISON will be in November. You need to do this to figure out the best viewing location possible – which will be somewhere high up, with a clear, low horizon in the direction you want to be observing in. You can get a good idea of a location’s suitability by playing about on Google Earth and a planetarium program for a while, but you can’t beat getting in the car and just driving about on a scouting expedition. But don’t just go in the daytime – go at night, then you’ll see what it’s like for light pollution, passing traffic and such variables as the number of, um, “courting couples” who go there after dark who might not appreciate someone setting up a camera close to their car while they’re there!

Having found a suitable location, take all your camera equipment up there to
“get a feel” for the place photographically, i.e. take test shots to see what
kind of foreground etc you’ll have when you go up there to take comet photos or just to look for it/them. Try out all your different lenses, not just your
standard lens.

Then do a little harmless speculating. Having found your site, have a think
about what you *might* see there later in the year, and plan accordingly in
terms of photographic viewpoints, lenses, etc. (i.e. say toyourself “If the tail
is *this* long, it’ll stretch from there to there, and I’ll need *this* lens…
but if the tail grows to *THIS* long it’ll stretch from there to *there* and
I’ll need **this** lens”) This isn’t being overly optimistic or unrealistic,
it’s just being prepared.

At the end of all that you’ll have a “perfect spot” that has a great view of the
sky, visually and photographically, and you’ll be confident that you can just go
there, at short notice if you have to take advantage of a break in the weather,
set up, and get the best out of this amazing opportunity – whatever “the best”
turns out to be.

2) If you haven’t got any, BUY SOME BINOCULARS! The naked eye view of Comets PANSTARRS and ISON will be very nice, of course, and you don’t NEED binoculars, but I very, very strongly suggest you get yourself a pair because they will add so much to your enjoyment. They’re not expensive, and they will show you the comet’s structure in lovely detail. But don’t be tempted to get a cheap pair from your local market, no matter how impressive or shiny and black they look. They often have horrible coatings on their lenses which are no good for astronomy. No. Go to your local camera retailer, and buy yourself a pair of good binoculars, you’ll thank me when PANSTARRS is in the sky, trust me. And don’t get any too powerful! Don’t fall for the hype and buy a great hulking pair of 20x80s or 30x100s or whatever. These are so heavy they need a tripod. No, just buy a simple pair of 7×35 “birdwatching” type binoculars, or a standard “10×50″ pair and you’ll be fine. (By the way, if you have one of those short, stubby birdwatching telescopes then you will get great views of the comets through that!)

3) Start to follow the progress of the comets on the web. Check the astronomy magazines’ websites for updates and reports to keep on top of the story.

…and finally…

4) If you’re new to astronomy, getout on any clear night you can now just to get a feel for the night sky. Then, when March coms, and PANSTARRS is shining there in the west, you’ll appreciate just how unusual and lovely it is.

…so, that’s a quick guide to what comets are, and do, and how you can observe them. There’s just one thing left to do now – cross our fingers that ISON behaves itself!