What’s Out Tonight?

Observing Mars

Upcoming months and years to BEST observe Mars.
It will be very bright at these times, rivaling Jupiter.

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Mars will be very bright and closest to Earth around January 15, 2025.
It will, unfortuantely, be on the smaller side compared to other close approaches.

Upcoming years when Mars will be close to Earth

December 2024–February 2025  •  Best around January 15, 2025  •  Size on the 15th will be 14.4 arc seconds
January–March 2027  •  Best around February 19  •  Size on the 19th will be 13.7 arc seconds
February–April 2029  •  Best around March 25  •  Size on the 25th will be 14.4 arc seconds
April–June 2031  •  Best around May 4  •  Size on the 4th will be 16.9 arc seconds
May–July 2033  •  Best around June 27  •  Size on the 4th will be 22.0 arc seconds
August–October 2035  •  Best around September 15  •  Size on the 15th will be 24.5 arc seconds

The best time to observe Mars in a telescope is when it gets close to the Earth, which is about every two years (see above dates). At this time it is very bright, rivaling Jupiter in brightness, and “big” in a telescope. Otherwise, Mars is fairly inconspicious in the sky and rather small to more easily observe detail with a telescope.

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Click here for a GREAT 3-D image of Mars' surface (NASA)—you can move it around.

A drawing I made of Mars. The large white oval is the giant impact site called Hellas and it was shrouded in clouds.

Compare this photo to my drawing on the far left. No, I did not take this photo.

Opposition, the best time to observe Mars!

For this reason, Mars is often disappointing to first-time observers who just take a glimpse at the planet. So, below are some suggestion to help maximize your viewing of Mars’ surface features. 

Mars is small, so it is best observed around opposition when it is closest to the Earth and appears its largest. Opposition for Mars is directly in “back” of the Earth, where the Sun, Earth and Mars are in a straight line. At this time, Mars is rising in the east when the Sun is setting in the west. Oppositions with Mars occur about every 26 months, however, some oppositions bring us much closer to Mars than others because of the elliptical shape of orbits. The distance between Earth and Mars at opposition can vary from 35,000,000 to 63,000,000 miles. This difference effectively doubles the size of Mars in a telescope. Unfortunately, the next opposition that makes Mars a reasonable size does not occur until January 2025. Although the polar caps and surface coloration can be seen in small telescopes (4-inch to 6-inch), they can be subtle, especially the surface coloration.

Mars is at opposition when it is directly behind the Earth and in line with the Sun. It is closest to Earth at this time and at this time, Mars rises in the east as the Sun is setting in the west. This distance varies because Earth's and Mars' orbits are ellipses and not perfect circles as shown in the illustration. Jupiter, Saturn, Uranus and Neptune get in opposition with Earth, too.

Observing Suggestions

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A few months preceding opposition, the popular monthly astronomy magazines and internet sites usually carry in-depth articles which should prove helpful. Often, they include current maps of the surface markings and charts to calculate the side of Mars that will be facing toward Earth when you observe. 

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When you are looking at Mars through a telescope, you will notice that there are split-second moments when the view of the surface appears clear. It is during these moments of clarity that the best glimpses will occur. It is a rare night when you can look directly at Mars and plainly see the subtleties of the surface markings for an extended period of time. 

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Use a minimum magnification of 100x, but 200x to 300x is preferable. Achieving higher magnifications is dependent on your telescope and atmospheric conditions. 

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Try to observe Mars often from one month before to one month after opposition. Repetitive viewing will increase your familiarity with this Planet and increase your chance of observing on a good night. Additionally, you will be able to see the different sides and all of the surface markings on Mars if you observe over a period of time. 
A motorize telescope mount that will follow celestial objects is best to have if you really want to study Mars's surface features.

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Observe Mars when it is highest in the sky in order to minimize atmospheric disturbance. This will occur around midnight during opposition. It is more difficult to see the surface markings when Mars is low in the sky (below 30°). The worst part about observing later is staying up or waking up. But, if you are into “this” it is worth it. Mars is only at opposition every couple of years. 

If you follow suggestions 1 thru 5 and still cannot see surface markings, here are some possible reasons why. a) Wind storms on Mars could be kicking up dust and obliterating the surface markings. Search the internet to check on Mars’ weather. b) Your telescope optics may not be properly aligned. Ask an astronomy club member or a telescope store to check out your telescope if this is something you cannot perform. c) The turbulence in Earth’s atmosphere may be affecting telescope image quality, so keep trying. d) Finally, remember that if you take your telescope from the warm interior of your home to the cold outside, it will take up to an hour for the telescope optics to cool and settle down. The image of Mars during this time will be blurry. Keep your telescope outside or in an unheated space before observing.

Major Surface Features on Mars

Direction of rotation >>