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Red Planet Reverie

by Perry Pezzolanella

Spring will be just around the corner when a bright ruddy star dominates shortening winter nights. The ruddy star is Mars and it will return to the evening sky for another opposition on March 3, which means it will be up all night, but due to its highly elliptical orbit, it will be at its closest, largest, and brightest on March 5. On that date Mars will be 62.6 million miles from Earth and 13.88 arcseconds across, sparkling at magnitude -1.2.

Mars is interesting to observe because it is the only planet that clearly displays a solid surface. It is a rusty desert world of windswept sand dunes, towering volcanoes, gaping canyons, craters, and two polar ice caps. These polar ice caps are the easiest to see and are composed of frozen water and carbon dioxide. During this opposition the north polar ice cap, which will point toward Earth, will be prominent as it emerges from the long northern winter but may still be covered with haze and clouds. It will be fascinating to watch the changes as the ice cap slowly melts and recedes with the advancing spring. Mars has several dark and bright features that will be visible provided there are no dust storms raging across the planet at the time. The darker, brownish areas are primarily dust-free rock outcrops with the largest and darkest being a wedge called Syrtis Major. Sinus Meridiani (Meridiani Planum) is where the Opportunity Rover landed in January 2004. Solis Lacus is another prominent dark feature that looks like an eye and is often nicknamed the “Eye of Mars”. Hellas is a deep impact basin over 1000 miles across that is filled with very fine, highly reflective dust that can be confused for clouds or the south polar ice cap. Mars demands extreme patience when it comes to observing; several nights of observing will train the eye to focus on detail. Larger telescopes will improve the view along with the use of orange or red filters. The features are usually subtle, but Mars will be reasonably high in the sky near the Virgo-Leo border where air turbulence will be less.

The first row of diagrams that follow show a complete surface map of Mars with the most prominent features visible as well as the polar ice caps. Three different global views follow with the darkest and most prominent surface features shown. The dates in the third row indicate when these features will be nearly centered on Mars at 10PM EST (11PM EDT). These provide views for a few hours either way or a few days around the given dates. Since Mars rotates on its axis in 24 hours and 37 minutes, these features will shift throughout the night. The rotation rate from Syrtis Major to Sinus Meridiani is six hours. From Sinus Meridiani to Solis Lacus is another six hours. If Solis Lacus is visible, then it will be another twelve hours before Syrtis Major returns to view. The fourth row indicates the change in size and brightness for Mars during this apparition.

The best time to observe Mars is when it is larger than 10 arcseconds across. This will occur from January 12 through April 29, which will provide a reasonable period of time to train the eye enough to make sketches or to take photos and video. The retrograde path of Mars among the stars from January 25 until April 15 can also be observed and plotted. Take note of the changing phases of Mars as it becomes noticeably gibbous by May with only 90% of its disc being lit by the Sun as seen from Earth.

Due to its very elliptical orbit, not all oppositions of Mars are good. This one is as poor as it gets with future oppositions getting progressively better. During the opposition of April 8, 2014, Mars will be 15.2 arcseconds across and on May 22, 2016 it will be 18.2 arcseconds across. The best opposition ahead will be on July 27, 2018 when Mars will be 24.3 arcseconds across. The aggressive exploration of Mars has made it a familiar planet worthy of viewing through the eyepiece. One can sit in a reverie and ponder the historic telescopic observations of Mars with the one that is visible in the eyepiece tonight.