Mars

Mars frustrates more beginners than any other planet. It’s bright, it’s famous, and everyone wants to see the “red planet” up close. Then they point a telescope at it and see… a tiny orange dot. No canals. No polar caps. No obvious surface features. Just a small, featureless disk that looks like it might be slightly fuzzy around the edges.

Here’s why: Mars is small and usually far away. Its diameter is only about half Earth’s - roughly 6,800 km. For most of its orbit, Mars appears between 4 and 8 arcseconds across in a telescope. That’s tiny. Jupiter, for comparison, appears around 40-45 arcseconds at opposition. Mars at a typical distance looks like a planetary dot, not a disk with visible detail.

But every 26 months, something changes. Earth and Mars align at opposition, and Mars swings relatively close to us. During favorable oppositions - which happen roughly every 15-17 years - Mars can approach within 56 million km and swell to 25 arcseconds or more. Suddenly, that tiny dot becomes a respectable disk, and surface features pop into view.

What You Can See

At a good opposition with decent seeing, Mars rewards patience. You’ll see the polar ice caps as bright white spots at the north or south pole (depending on Mars’s seasonal tilt). You’ll see dark surface markings - regions like Syrtis Major - contrasting against the lighter desert areas. The overall orange-red color is obvious. With larger apertures (200mm+) and excellent seeing, you might catch faint hints of surface detail: darker regions shifting as Mars rotates, occasional dust storms brightening parts of the surface, seasonal changes in the polar caps.

Mars rotates in about 24.6 hours, so if you observe over several nights, you’ll see different faces of the planet as it turns. Surface features come and go. This makes Mars dynamic in a way Venus and Mercury aren’t.

But here’s the catch: seeing matters enormously. Mars is small, so you need high magnification - 150x, 200x, or more. At that magnification, atmospheric turbulence becomes your enemy. On a poor seeing night, Mars just shimmers and blurs. On a steady night, it snaps into focus and reveals its secrets. Planetary observing is all about waiting for those moments.

When and How to Observe

Mars reaches opposition every 26 months. These are your best windows. Check when the next opposition occurs and whether it’s favorable (Mars closer than 70 million km) or not. Even at opposition, Mars rewards aperture. Small telescopes (60-80mm) will show the disk and maybe a polar cap, but little else. Medium telescopes (150mm) start revealing surface markings. Larger scopes (200mm+) show real detail if the seeing cooperates.

Use high magnification and be patient. Watch Mars for 10-15 minutes. The atmosphere will waver and blur the image, but every few seconds, it steadies, and details pop into clarity. Observe during those brief moments of steady seeing.

Color filters help. A red or orange filter enhances surface contrast. A blue or green filter makes polar caps stand out. Experiment to see what works for your eyes and equipment.

The Bottom Line

Mars is a patience game. Most of the time, it’s not worth observing - too small, too far, too little detail. But during favorable oppositions, it transforms into one of the most rewarding planetary targets. If Mars is near opposition, absolutely observe it. If it’s not, check its apparent size in an app. If it’s under 10 arcseconds, you’re better off spending your time on Jupiter or Saturn. Mars will come around again. When it does, and the seeing is good, and you catch a glimpse of Syrtis Major or a gleaming polar cap - that’s when Mars earns its reputation.