Witness the Majestic Mars: A Celestial Showdown at Opposition

The 2018 dust storm persisted from June through September. I captured this image on June 27, shortly after the storm enveloped the planet, using my Celestron 8-inch SCT. You can barely discern Valles Marineris, a canyon stretching 2,500 miles, close to the center. Credit: Molly Wakeling

At public star observations and gatherings with friends at the telescope, we cherish every opportunity to gaze upon the marvels of Saturn and Jupiter. Throughout the year, whenever they grace the sky, they never fail to impress. Conversely, Mars can be easily overlooked as it often seems small, thus making it challenging to distinguish the remarkable details visible on the gas giants.

However, every 26 months, the paths of Earth and Mars align, granting us a closer glimpse of the Red Planet during opposition — set to occur on the night of January 15 this year. In the early evening, Mars will be easily found: It will shine brightly as a reddish starlike object just beneath Castor and Pollux, the twin stars of Gemini, almost due east. It will ascend quickly, reaching a nearly overhead position at midnight for the southern U.S., and will still be high in the sky for the remainder of the country.

Though you can observe Mars as a small disk using binoculars, detailed viewing requires a telescope. For planetary observation, long-focal-length telescopes are beneficial — my personal favorite for viewing planets is my Celestron 8-inch Schmidt-Cassegrain, which has a focal length of 2,032 mm. The level of magnification obtainable with Mars greatly relies on the local atmospheric conditions — in other words, the stability of the atmosphere. If the conditions are favorable, opt for your most powerful magnification eyepieces, or use a Barlow lens with a lower power.

For nights with average atmospheric conditions, a good guideline is to apply a magnification range of 30x to 50x times the aperture of your telescope measured in inches. For instance, with my 8-inch telescope, using 240-400x should be effective, which suggests utilizing 5mm to 8.5mm eyepieces. A simple Plössl — not the most intricate eyepiece design — can provide gratifying views. Experimenting with color filters can also be beneficial if you have them, to enhance the visibility of different features. Just don’t anticipate seeing color.

When observing Mars, three primary features are readily apparent: light-red dusty terrains, darker patches of exposed volcanic rock, and the white polar ice caps. Early astronomers named the lighter areas as land formations, such as Elysium Planitia (the Elysium Plain), and labeled the darker regions as bodies of water, like Mare Tyrrhenum (after the Tyrrhenian Sea in the Mediterranean). The polar ice caps change throughout the martian seasons, and our capacity to observe them is also influenced by the tilt of Mars, yet I find spotting them to be particularly thrilling. With some persistence and a Mars map, you can identify the features in view. I utilize the SkySafari mobile application to determine what is currently observable by zooming in on Mars and tapping on its features. The Red Planet completes one rotation approximately every 24 hours and 40 minutes, so observing it throughout the night will reveal various features, as will monitoring it over a few weeks.

Mars is also noted for more fleeting phenomena. Despite its significantly thinner atmosphere compared to Earth, clouds can form on Mars, particularly above the extensive basins. The martian volcanoes tend to draw in these clouds. Using a blue or violet filter can assist in viewing the clouds more effectively.

Mars is famed for its dust storms, which can occasionally wrap around the entire planet — as was the case in 2018. During such events, Mars takes on a light red and featureless appearance for weeks or even months. The storm of 2018 ultimately led to the demise of the Opportunity rover 5,352 sols (martian days) into its mission. These storms alter the appearance of the martian landscape, explaining why maps of the fourth planet from decades ago appear distinct from the current ones.
There are numerous captivating features to appreciate while gazing at Mars; one can truly grasp how closely the dusty planet resembles our own. If you find it impossible to observe it precisely at opposition, don’t fret — it will remain large and luminous for several weeks as its distance from Earth expands. Personally, I enjoy listening to Gustav Holst’s “Mars, the Bringer of War” while observing it through my telescope. Wishing you a delightful Mars opposition!