Spotting a comet in the night sky isn't always as simple as going outside and looking up. Some comets on rare occasion can be seen pretty easily with the naked eye. But most of the time it takes some knowledge of the night sky, seeking out ideal viewing conditions and using the right equipment, and maybe even using some unorthodox techniques to really see what all the fuss is about.
Using these 18 tips altogether can greatly increase your chances of witnessing one of the coolest phenomena our night sky has to offer. And perhaps in time, you'll become skilled enough and contribute to Science with your very own amateur comet photos.
Finding the Comet, Know When and Where to Look
1. Know what days and time of night are best to view
Of all the tips, this is perhaps the most obvious but also the important. Depending on the proximity and trajectory of the comet to Earth, there will certainly be days when visibility is better than others. And within those days, the time of day is equally important. Usually comets are best visible in the early morning hours, between 2-6am. But sometimes visibility is best earlier in the evening just as the sun is setting, or in rarer cases during the day if the comet is exceptionally bright. Many comet watching websites routinely post the best days and times to view any given comet, including rise, peak and set times for your location. Stay updated and plan accordingly, including tracking the weather for less cloudy nights.
2. Location, location, location
Knowing the best days and time to look doesn't automatically grant you visibility to all comets, unfortunately. The truth is most comets are best visible (or only visible) in certain spots of the world, depending on the comet's trajectory and magnitude (visual brightness). Sometimes its better to be in the northern hemisphere vs the southern, or vice versa. Some countries will have better visibility than others, and the same for states. And of course the days and best times to view are dependent on where you live as well (or where you are willing to travel to).
When you research best days and times, pay close attention to which parts of the country give you the best visibility. Your city or state might not be ideal, but that doesn't always rule you out. Check maps and look for better viewing spots, usually off the beaten path a little or away from light pollution (more on that below).. perhaps a mini road trip is in order.
3. Follow the latest news; best dates and times can change
In keeping with #1, be aware that comets can change their path and magnitude (visual brightness) among other things as they travel through space. So what we know about the trajectory, speed and brightness of XYZ comet one day could change the next. It's best to stay up-to-date on the latest news of the comet you wish to see as much as possible. Recommend checking out the latest news the day of (or even 2-3 hours before) you plan to view.
4. Use your smartphone or tablet to best spot the comet in the sky
Once you know the when, figure out the where. One of the best ways to figure out where a comet actually is in the night sky at any given moment is by using your smartphone or tablet. There are many apps that map the night sky for you, showing you constellations, planets, and yes even where comets are right now. Some of these apps are free (or at least offer a free trial), while others are more pro and cost, either with in-app purchases or monthly subscriptions (usually around $3-5/month). But most have the ability for you to point your phone or tablet into the sky and see where everything is at. You can also customize what you see and use search features, and learn about any given object in the sky with info buttons.
I have used Night Sky (iOS version) many times and am amazed at what you can learn from a free app on your phone. Also recommend these, just to name a few more, all of which at least come with a free trial and can be used in their basic form for free:
SkyView - iOS, Android
Star Walk - iOS, Android
5. Orient yourself with constellations and bright stars
Now that you have a nifty means of using your smart device to map the sky, it helps to orient yourself and try and learn where the brightest stars are, and some of the constellations. You don't want to have to hold your phone or tablet up the whole time. So if you can learn a few reference points, and fix your attention on the location of the sky where the comet is supposed to be visible, you can then enjoy the viewing experience more. Especially if you are using binoculars or a telescope, or better yet trying to take a photo.
Ideal Viewing Conditions
6. Seek out the darkest and most moonless of nights
You'll come to find the best time to view an object in the sky is when the night is at its darkest. That means ideally moonless, as even the moon's light can obstruct your view. The more light gone from the night sky that's not of the comet's, the more likely you can see the comet in all its glory. Perhaps even with the naked eye. You can sometimes see the brightest comets at dusk or dawn as well, though that's rare.
7. Find a panoramic, transparent view of the night sky, unobstructed
Dark and moonless ideally sure, but also try and pick a viewing spot that doesn't have any visual obstruction in your way, like mountains or buildings. Or clouds. Ideally its a pitch dark night without the moon's light or a cloud in the sky, and you have a full panoramic view of the entire night skyline, 100% unobstructed.
8. Be away from light pollution
This one is easy. City lights make it hard to see the stars. It's called light pollution. And light pollution also makes it hard to see celestial events, like a comet streaking by. Seek out a spot that's dark as possible, including as free from artificial light as possible. It's not that you'll never see a comet in the big city or even a moderately lit up suburb, but you will never see it as good as being somewhere without light pollution.
9. Be in a high spot, elevated
The last recommendation for creating an ideal viewing condition for comet watching is to seek out a spot with altitude. Being higher in elevation gives you a better view of the night sky, less to zero obstructions and typically comes with less light pollution.
Equipment & Techniques
10. Use combo of binoculars, a telescope, and your naked eye
Comets can actually be seen most every night, with the right equipment. They are just faint, even with a good telescope. But every 1-2 years we get to see a comet with a basic set of binoculars (7x50 mm or 10x50 mm strength). And every 3-5 years or so we can all expect to see a comet with our naked eye. And then there's the once in a decade or even a generation 'great' comet that takes little effort at all for the whole world to see. Know what kind of comet you are trying to view, and bring the right equipment. Even if you can see the comet with your naked eye, bringing along a good set of binoculars ups the ante, and will certainly enhance your viewing experience. And what you think of as a moderate or large backyard telescope is the next level beyond that.
11. Have patience, all in good time
Even when you are in the perfect spot and know exactly where to look, on the best day and time imaginable according to all the Science blogs and articles, you still might have to employ some patience. Don't expect a comet to appear on an exact timetable. Allow for a large window of time and be patient. Usually a window of 1-3 hours is ideal. So bring a friend, family members or some good music to pacify the wait time, or just enjoy the peace and quiet until the moment arrives.
12. Dark adaptation, give your eyes a chance to adjust
Be aware that it does take your eyes some time to adjust from daylight to darker light conditions. Scientific American says 'dark adaptation' typically takes between 20-30 minutes to reach its max, while research from a physicist at the University of Illinois at Urbana-Champaign, Rebecca Holmes, shows that our eyes could take up to 2 hours to fully transition into ideal 'night vision' mode. Either way, allow some time for your eyes to adjust to the darkness; this includes phone or tablet screens. So if you are using a smart device to map the sky, its best to put the device away at least 30 minutes before you expect to see the comet.
13. Averted vision, look from your peripheral for better results
Averted vision is the technique of looking out of the corner of your eye to see faint objects more clearly. While the idea of 'night vision' is super cool, fact is most of us don't really have it. Sure we can make use of dark adaptation, but once that kicks in we can 'hack' the limits of our eyes by using this trick for even better effect -- How to master the art of averted vision.
14. Light shrouds, block light from your telescope, field of vision
Light shrouds are optical tube coverings for telescopes. They block light from entering the light path within the telescope. Many different options exist online, or some telescopes come with them. A worthwhile investment; again the less light from sources other than the comet itself, the better. You can even get shrouds to put over your head to absolutely block out all possible light between you and your telescope/binocular eyepieces. Nothing too fancy, a blanket should work fine.
15. Eyepieces, consider their zoom/strength ranges and your skill level
While great comets can be seen with the naked eye or most any pair of decent binoculars, most other comets require a keener eye and better tools. Once you generally know where to look and are in ideal viewing conditions, seek out the most appropriate eyepieces for your telescope or a solid strength/zoom range for your binoculars. There are pros and cons to different levels of magnification -- you can really zoom in on a comet with great magnification, but you might be too zoomed in to see it in real time unless you are quite skilled. Conversely, you won't see as much detail but can have a greater field of view with less magnification. Put your research skills to the test and invest time into thinking about what eyepieces work best for you and your viewing goals. No doubt will require some trial and error to get right.
16. Use deep breathing to oxygenate the brain and enhance visual acuity
This might sound odd but you can actually use a method called 'deep breathing' to send more oxygen to your brain, which if done right can increase your visual acuity (ability to see better) by an another magnitude, which is no trivial amount of enhanced eyesight. Even more, its free to try and also reduces stress in general.
17. Tap your scope, human eyes are better at detecting objects in motion
Contrary to what you might think, lightly tapping on your telescope to give your field of view a slight shake over a perfectly stationary viewing experience can actually help you spot a comet more easily. Fact is, human eyes are better at detecting moving objects vs stationary ones. Of course you want your telescope lens to be mostly stationary. But if you are certain you are looking at the right spot and can't see the comet, give it a try. It might just magically appear for you.
18. Take a photo to commemorate the moment, and help Science
I am no camera expert, but I found this video quite fascinating. And if you want to be able to actually capture a great photo of a comet, this is an excellent resource to start with to point you into the right direction. You can see all the factors you need to consider to get the best shot, and how much it can be trial and error.
And once you capture an image of the comet, even if you think it's just subpar or OK, the Science community could make use of it. Professionals that get to use and play with the best and most advanced telescopes the world has to offer are in truth very limited to what they can photograph. There is simply too much sky and too many comets to capture them all at the highest level. That's where amateurs can play a role in helping Science advance by capturing images of comets from all over the world, and uploading those images online. Here's one such cool story to illustrate the point -- Amateur Astrophotographers Unwittingly Help Scientists Track Comet.