So, a bright comet is on the way… we hope! How do you observe it?
It all depends how bright it gets, and we can’t predict that yet. Originally, soon after it was discovered and its orbit was calculated, lots of people were claiming ISON would be dazzlingly bright, but now we think it will be rather more modest. Still a naked eye comet, and still a big “sky event”, but not a celestial spectacular. But then again, comets are notoriously unpredictable, and anything could happen.
Whatever happens to ISON, however bright it gets, you’ll want to see it, right? That’s why you’re here! But before we look at how to actually observe comet ISON, and look ahead to what it might look like, 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. Like this…
* 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 more powerful 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 absolutely 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 (“astrophotography”) 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 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.
There’s a whole page on this blog dedicated to comet photography.
PREPARING FOR ISON
To prepare for observing Comet 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 ISON will be in your sky in October, November and December. 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
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 ISON should 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 red, orange or green 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, with a purple-blue coating on their lenses. You’ll thank me when ISON 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) If you’re not doing so already, start to follow the progress of the comet on the web. Check the astronomy magazines’ websites for updates and reports to keep on top of the story.
4) If you’re new to astronomy, get out on any clear night you can now just to get a feel for the night sky. Then, when ISON is in the sky, shining there, you’ll appreciate just how unusual and lovely it is.
5) DON’T RUSH OUT AND BUY A TELESCOPE TO LOOK AT COMET ISON WITH!!! Honestly, there’s no need. ISON is hopefully going to be big enough and bright enough to be found and seen without a telescope, so unless you’re already “into” astronomy then buying one just for oggling ISON will be a waste of time. No. Telescopes are for skywatchers who are already experienced in looking at things in the sky, and who know where things are “up there”. Astronomers use telescopes to zoom in on objects in the sky, but if you don’t know where those objects are, when they’re visible (the sky changes week to week and season to season), etc, they’re no use to you. Honestly, a good pair of binoculars will give you views of ISON you’ll treasure. And if you really want to see it through a telescope, get in touch with your local astronomical society which will almost xcertainly be holding “Comet Watch” events you can go along to.
…so, that’s a quick guide to what comets are, and do, and how you can observe them.
* * * * * OBSERVING COMET ISON * * * * * *
Now… what might Comet ISON look like later this year, and how can you see it at its best? Well, going by the latest observations and predictions, here’s what we might be looking at.
By late October Comet ISON should be visible in binoculars, looking something like this…
This is how Comet ISON might look to the naked eye, a couple of hours before sunrise around Nov 5th -10th – a short, stubby streak of light…
This is what we MIGHT see through binoculars at that time…
By late November, we might be seeing this in the eastern sky before dawn – a still quite short but brighter streak of light, with ISON sporting a characteristic “comet tail”…
Through binoculars, might we see something like this..?
By early December, when ISON has rounded the Sun, we might see something like this in the sky before dawn…
Personally, I’m hoping to see this from Kendal Castle at that time…
And if we scan up and down a long comet tail like that with binoculars, what might we see..? Something like this..? Kinks and streamers embedded in the tail?
No idea! It would be nice though!
So, there you go… what comets are, and what ISON might look like to the naked eye and through binoculars. As I will be saying a gazillion times through this blog…
We’ll have to wait and see… :-)