Planetary viewing can be one of the most challenging, yet rewarding forms of amateur astronomy. Planetary observation is demanding of both your equipment and your viewing skills. Viewing skills? That sounds too much like work, right? Actually, improving your planetary skills is much easier than it sounds. Follow these simple tips to greatly improve your time watching that favorite planet.
Try sketching what you see
Next time you're at the eyepiece, take along a pad of paper and a pencil. Even if you're not a great artist, getting into the habit of sketching while observing will train your eyes to look for every last bit of detail. This way, you can fill in your sketch. Because of this effect, you will start noticing smaller and finer detail on planets' surfaces. Even if you are horrible at drawing, this practice can help you become better at seeing detail.
This technique is especially useful on Mars, where surface contrast is relatively low, and every little bit can help. In this case, take your sketch inside after you're done and compare it to a map of Mars at the time you observed. Don't look at the map first, or you might "see" detail that isn't actually there.
Check out the planet's weather
While observing some of the more active planets such as Mars, Jupiter, and Saturn, don't overlook their weather! Mars frequently has massive dust storms that can obscure surface details. Jupiter has the Great Red Spot and many other very interesting cloud formations. Saturn has less noticeable weather, but does change slightly from time to time. Over the course of a few nights, watch the weather patterns on any given planet, and note trends in the planet's weather.
Try color filters
Color filters can be used to increase contrast in certain areas of planets. For example, a 23A filter (the red filter at right) works great on Mars by increasing the contrast of the markings on its surface. An 80A or 82A filter (similar to the blue filter at right) can help to bring out more detail in Jupiter. Another advantage of using color filters on planets is that it can reduce light transmission. This would sound like a bad thing, except most planets are too bright for proper viewing. Dimming them down helps to let your eye see more detail. Check out this page for help in selecting a good filter for your favorite planet.
Check your equipment
Before heading out to observe a planetary object, make sure your equipment is in good working order. This is especially true for those of us using reflecting telescopes. These telescopes require careful collimation in order to deliver optimum performance. Collimating a scope takes about five minutes once you get the hang of it, and makes a huge difference in image quality (especially at high magnification).
It is also important to allow your telescope to cool off or warm up to the ambient air temperature. A telescope that is warmer or cooler than the surrounding air will have very poor optical performance, and may discourage beginners from trying to view planets in detail. Letting your telescope cool for at least a half-hour before viewing will reward you with excellent views of both planets and other objects.
So next time you set out to observe your favorite planet, remember these tips. They could make the difference between you seeing details and not!