How to find Mars!

The fourth planet from the Sun, Mars is a bright reddish dot in our night skies. To find it, look low the southeast sky after the sky gets dark.

Southeast is on the other side of the sky from where the sun sets. By 9:30 pm local daylight time, about the time it gets dark out, Mars will have risen above the southeastern horizon.  It will rise a bit earlier each night.  Mars will be highest in the sky about midnight in May and by 11pm in June.


Mars and Saturn low in the southeast sky at 9:30pm Daylight Time.

You can use the star chart above from the or the map for May (and June, when it’s published) to find Mars in the sky.

What will you see in a telescope?

If you point a telescope of any size at Mars and focus it carefully, you’ll see a tiny reddish dot.  Once you get the planet centered in the eyepiece, take a good long look and see if you can pick out any gray or light colored areas.  Then use a higher power eyepiece to see how much detail you can see on Mars.  It’s still going to be small.  How much power can you use?  A good rule of thumb is to find out the highest power you can use is to measure the opening where the light comes though in millimeters and multiply it by 2.  A 2.4 inch objective (where the light comes into the telescope) is about 60 millimeters wide.  Multiply that by 2 and the maximum usable power is 120x.  See if your telescope came with eyepieces marked with power ratings or if the materials with your telescope tells you what power the eyepieces can give. If you have a ‘barlow’ lens, multiply the power by the ‘2x’ or ‘3x’ stamped on the side to get the total power.

If Mars is very fuzzy, it’s either a night with a turbulent jet stream overhead or you are using too much power.  The gray areas are areas of volcanic rock where the reddish dust has blown off the solid rock.

While you are in the neighborhood, Saturn rises about an hour and a half after Mars rises, so check out the ringed planet.  While you are waiting for Mars to get above your trees, look for Jupiter, just as bright as Mars higher in the southwest sky.  They are also on the sky maps.

Added May 23rd… A more detailed discussion of what your telescope can see on Mars is at astrobob in Duluth, MN:

Happy hunting!





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