The Red Planet

Mars may be slipping low in the sky for observers in the Northern Hemisphere, but don’t let that stop you from observing the Red Planet while you can. Each sketch provides a building block of experience for capturing those elusive details for which Mars is notorious. During your observations, you can expect to see atmospheric features and even surface detail. Over time, observers can follow seasonal fluctuations and changes in martian albedo (reflectivity).

In mid-April, Mars begins retrograde motion in Ophiuchus and will move westward against the stars. The planet slips into Scorpius on May 22, marking the date of opposition when Mars is on the opposite side of Earth from the Sun. By May 30, it will lie near the border of Libra for its closest approach to Earth. Its apparent diameter will reach 18.6''. As a bonus, the North Polar Region is currently tilted toward Earth so that the clouds that form over both polar regions may be visible.

One method to maximize your view is to use the highest magnification that seeing (atmospheric steadiness) allows. Another is to use filters to increase the sharpness of martian features. For example, refer to the set of comparison sketches provided by Carlos Hernandez (Image #1). For the first observation, he used a Wratten 30, which is a magenta filter that enhances blue atmospheric and red surface features while absorbing green hues. Notice the projections he captured extending from Solis Lacus near the preceding limb and the bright streak within Mare Sirenum in the southern hemisphere. A Wratten 38A (blue) filter worked to highlight limb haze and clouds in his second observation.

Sol Robbins used a variable filter system for his Mars observation (Image #2). This unit sports a wheel to adjust the filter’s color transmission, which saves time and prevents distractions caused by swapping out filters. Note the remarkable amount of detail he recorded in a short timespan while using a 3.5-inch refractor.

Study the eyepiece view before you begin sketching. Then, create a 2-inch circle on your paper and draw in the phase. Record the universal time and date next. A soft white observing light works well for planetary sketching, especially if you’re using colored pencils. Strive to complete the sketch within about 20 minutes before features rotate out of view.

Outline the polar caps and prominent surface details first. Fill in the darkest and then the lightest areas next before blending your sketch with a clean, soft blending stump. Working in small sections, refine your sketch with a pencil by homing in on the finer details. Finally, use a kneaded or shaped eraser to draw (by lifting the graphite) clouds and haze and to make final adjustments in tonal variances. Record the time once more, and then mark the orientation (north and east or preceding [disappearing features] and following [appearing features]) to complete the sketch.

Questions or comments? Feel free to contact me at erikarix1@gmail.com.