How To Observe Mars This Week
If you have clear sky this week, try to get outside to take a look at Mars. While the Red Planet never easily reveals its surface features, this week’s view is a good as you’ll get for a while: the planet won’t get this close again until 2012.
Note: In our last article, we incorrectly listed the diameter of Mars as 3400 km. Thanks to subscribers G.F. and A.B. for pointing that the RADIUS of Mars is 3400 km. We’ve made the correction.
While Mars looks lovely in the sky right now, to see any detail on the surface of the planet, you’ll need a telescope. Binoculars will enhance the color of the planet, but won’t show the disk of this small world.
And if you have a telescope, temper your expectations. No matter how big your scope, Mars won’t look anything like images you see the magazines. In a small telescope, Mars looks tiny and gives up little detail at a glance. Astronomy writer Timothy Ferris said of observing the planet, “Observing Mars through a telescope is like watching the Dance of the Seven Veils: seldom are you certain of exactly what you’ve seen, but it’s enough to pique your interest”.
Look at this picture from 10 feet away to get an idea of what you might see in a small telescope:
With a little patience, the right tools, and some steady sky, you’ll see something even in a 3″ scope. Especially if you follow these suggestions…
* Acclimatize Your Telescope. Bring your scope out at least 30-60 minutes before you plan to observe. By cooling it down to the ambient temperature, you’ll prevent air currents inside your scope from degrading the image of the planet.
* Pick a Night With Steady Air. While Mars is closest on Jan. 29, you’ll have a couple weeks afterwards to get a good view. So pick a night when the stars aren’t twinkling too much. Vigorously twinkling stars mean poor seeing, even if the sky is clear. Sometimes, nights with a little haze have steadier air than crystal-clear nights.
* Use High Magnification. Forget about your wide-field, low-power eyepieces. Start with whatever eyepiece gives you 80-100x. Then work your way up until the image becomes too blurry or dim. If you have steady sky, you might get to use a magnification of 50-60 times the diameter of your telescope’s objective (in inches), at best.
* Wait For Good Seeing. Remember the “Dance of the Seven Veils”. As you watch the disk of Mars, you’ll see it shimmer and dance as pockets of warm and cold air move through the column of atmosphere above you. Keep watching and waiting for brief moments when you the air is steadiest. You’ll suddenly see sharp details snap into view for a few moments.
* Try Color Filters
To get better contrast, use a set of colored filters if you have them. Here are some suggested filters for your Mars observing sessions:
-Yellow (#12, #15) may brighten desert regions and darkens bluish and brownish features.
-Orange (#21, #23A) further increases contrast between light and dark features, penetrates hazes and most clouds, and limited detection of dust clouds.
-Red (#25, #29) gives maximum contrast of surface features, enhances fine surface details, dust clouds boundaries, and polar cap boundaries.
-Green (#57) darkens red and blue features, enhances frost patches, surface fogs, and polar projections.
-Blue-Green (#64) helps detect ice-fogs and polar hazes.
-Blue (#80A, #38, #38A) and deep blue (#46, #47) shows atmospheric clouds, discrete white clouds, and limb hazes, equatorial cloud bands, polar cloud hoods, and darkens reddish features.
-Magenta (#30, #32) will enhance red and blue features and darkens green ones. Improves polar region features and some Martian clouds.
If you don’t have Wratten filters, try colored cellophane. Especially red or orange.
* Make a Sketch. To train your eye and your brain to see fine detail, try making a simple sketch of what you see. Every time a new detail pops out, add it to your sketch. Over 30 minutes, you will have a full record of what you have seen during the moments of optimal seeing.
* Observe Frequently. Because Mars rotates every 24 hours and 37 minutes, you’ll see almost the same face of the planet at the same time each night. So extend your sessions over several hours on one night, or at the same time over the course of the next month to see both sides of the planet.
Good luck with your Martian observing. And above all, enjoy yourself!
