Sneak Peek And Quick Observing Guide To April’s Opposition Of Mars

Mars and Spica rising together in the southeastern sky after midnight Feb. 1, 2014. Credit: Bob King

If you’re up very late, you’ll see a rather amazing sight these February nights. Around 12:30 a.m. two bright lights of very different colors dominate the southeastern sky – Mars and Spica. What a color contrast they make. The fiery orange planet hovers just a few degrees above the blue-white star; together they instantly draw your attention.

Tomorrow morning Mars and Spica will be in conjunction and just 4.6 degrees apart. Why not take this opportunity to get acquainted with the Red Planet? Already Mars has brightened to magnitude 0.2 (brighter than Spica) with a diameter of 9 arc seconds, big enough to make out the largest of the dark markings on its surface. Once believed to be continents and even oceans, these dusky smudges are windblown streaks and patches of dark sand and dust. Over time the features have changed shape and intensity according to the vagaries of Martian winds and weather.

About every two years, Mars and Earth line up on the same side of the sun at opposition. Because Mars’ orbit is eccentric (less circular than Earth’s) the two planets are closer at some oppositions than others. This year’s a relatively distant one. Illustration: Bob King

Mars reaches opposition on April 8 when it will line up with Earth on the same side of the sun and shine closer, brighter and bigger than it has since early 2008. With its axis tilted at 25.2 degrees, Mars has seasons much like Earth, though they’re about twice as long since Mars takes 687 days to circle the sun.

The planet’s northern hemisphere is about to bust out in summer with the season beginning on Feb. 15. Winter, along with its clouds and frosts, holds sway in the south.

If you’re lucky enough to have steady air with a minimum of atmospheric turbulence, give Mars a look. A magnification of 50x will show the planet as a small, featureless dot, but if you crank it up to around 200x, things become more interesting.

With the approach of summer, the north polar ice cap has been shrinking for months, but it’s still visible as a thin, white oval at the bottom of the planet. I say “bottom” because many astronomical telescopes flip and reverse images with north down and east to the right.

Two photos of Mars taken by Australian astrophotographers Maurice Valimberti (left) and John Kazanas on Feb. 1, 2014 show the shrinking north polar cap. The white patches are clouds over a region called Elysium.

For Western Hemisphere skywatchers this coming week, Mars presents a rich assortment of dark patches including the extensive Mare Erythraeum (Erythraeum Sea) – Aurorae Sinus (Bay of Dawn) – Margaritifer Sinus (Pearl Bay) complex. Because the planet still appears relatively small, the three might blend into one dark mottled mass when you attempt to view them in your telescope. To the north, you can’t miss the big, dark “finger” of Mare Acidalium (Acidalian Sea) sticking out from the shiny white polar cap.

Three views of Mars showing many of its most prominent dark markings visible through 4-inch and larger telescopes. Time shown is 1 a.m. CST but Mars rotates slowly enough that the features remain visible for several hours over several consecutive nights. Credit: Meridian software

Around about Feb. 14, Mars’ easiest to see marking, Syrtis Major (Gulf of Sidra), will face us square-on for several hours around 1 a.m. CST (2 a.m. EST). Be sure to watch for the large circular feature Hellas, a gigantic impact basin, just to its south. Hellas is often covered in clouds or frost in winter and mimics the appearance of the south polar cap, a feature currently hidden from view. To find out exactly which side of Mars is facing you when, download the free Meridian software created by Claude Duplessis.

Complete Mars map showing many more features. Click to learn more about Mars’ upcoming opposition. Credit: Association of Lunar and Planetary Observers (A.L.P.O).

I’ll have much more to say about Mars in the coming weeks as we approach opposition when it will become brighter than any star in the sky except Sirius. In the meantime, naked eye observers can watch the planet slowly brighten as it glides through Virgo. Those with telescopes can exercise their visual chops by taking every opportunity to examine the planet and its elusive features. As always with this wonderful hobby, the more you look, the more you’ll see.