Have you seen it? I’m talking about that super-bright and super-red “star” rising in the east in the early evening. That’s not actually a star but Mars. It’s easy to see why it’s called the red planet. While Mars is still far away, it’s the closest it’s been to Earth in over two years.
Mars and the Earth are less than 60 million miles away from each other right now. Every two years and two months, Earth and Mars catch up with each other in their respective orbits around the sun. Astronomers call this opposition, which is when both planets are at their minimum distance from each other. Not all opposition distances are the same though, because the orbits of Mars and Earth are not perfectly circular.
Another great thing is that Mars and the sun are on opposite sides of the sky. That’s why it’s called opposition. Just like a full moon, Mars rises at sunset and sets at sunrise, so it’s available all night long. That’s pretty much how it’s going to be for the rest of this month. The only other star-like object brighter than Mars in the evening sky is Jupiter, the largest planet in our solar system, beaming away in the high-southeast sky, not all that far away from Mars.
Mars will be making a fairly high arc across the southern half of the sky through the night, so it will be a prime target for even small telescopes. It really helps to wait until Mars rises high enough in the sky before you train your scope on it. That way Mars can rise above the thicker layer of Earth’s blurring atmosphere near the horizon. The higher Mars is, the better. You don’t have to wait until midnight but that’s when it’ll be at its highest, about 70 degrees above the southern horizon. As it is with all celestial objects, it’s also important to take long, continuous looks through your telescope so your eye can adjust to the light level inside the scope. You may also catch more transparent layers of the atmosphere as they blow through.
Another tip about using your telescope on Mars or anything else in the night sky is to be sure you let your telescope and any eyepieces you’ll be using sit outside for a good 30 to 60 minutes so all of the glass and mirrors can adapt to the outside temperature. It really makes a difference, especially in colder weather.
Mars is the only planet in our solar system where you can actually see the surface with a telescope. With other planets like Jupiter, Saturn, and Venus, all you see are cloud tops. I certainly don’t want to oversell what you’ll see on Mars, though. It’s still only a 4,000-mile-wide planet and nearly 60 million miles away. Even with higher magnification, it’s going to be far from filling up the field of your telescope eyepiece.
One of the easiest surface features that’s possible to see on Mars is the northern polar cap. With most telescopes, you see an inverted, upside-down image. If that’s how it appears in your scope, look for a white smudge on the lower right side of the disk of Mars as it first rises. It can be tricky to see. As Mars reaches its highest position in the southern sky, the polar cap will shift to the bottom of the disk. You may also see dark patches that are mainly the extensive valleys on Mars. Let’s keep our fingers crossed that there won’t be a global dust storm on Mars during this time. That can happen.
There are some great tools out there to help you spot surface features on Mars. Since Mars rotates on its axis every 24.5 hours, a little slower than the Earth, the surface features on Mars gradually and continually shift to the right. Using my favorite app, Sky Guide, you can zoom into Mars and keep up with its rotation and its shifting surface features. Sky and Telescope Magazine also has a great tool available on their website. It’s called the Mars Profiler, available at www.skyandtelescope.org/wp-content/plugins/observing-tools/mars_profiler/mars.html.
Occultation of Mars (Mike Lynch)
This weekend Mars has some close and very bright company — the nearly full moon is just above and to the right of the red planet. On Monday night, Jan. 13, the full moon rises right around sunset, extremely close to Mars, less than a degree away. Using even a smaller telescope or binoculars, watch the moon and Mars as soon as they’re above the horizon. Over the next few hours you’ll observe the moon creeping up closer and closer to Mars. Right around 8:10 p.m., the moon will cross in front of Mars and eclipse it until around 9:10 when Mars emerges from the upper right side of the moon. Astronomically, this event is referred to as an occultation. Whatever it’s called, it’s going to be quite a show you won’t want to miss.
Mike Lynch is an amateur astronomer and retired broadcast meteorologist for WCCO Radio in Minneapolis/St. Paul. He is the author of “Stars: a Month by Month Tour of the Constellations,” published by Adventure Publications and available at bookstores and adventurepublications.net. Mike is available for private star parties. You can contact him at mikewlynch@comcast.net.
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