This is the best time to see Mars. See the Red Planet this week and catch its waltz with the Moon

This is the best time to see Mars. See the Red Planet this week and catch its waltz with the Moon

Mars at opposition Robert Smith, Stevenage, Hertfordshire, 7 December 2022 Equipment: ZWO ASI178mc camera, Celestron AVX 9.25-inch Schmidt-Cassegrain reflector, Celestron AVX mount

Pete Lawrence

Published: January 7, 2025 at 9:32 am

Mars reaches opposition on 16 January 2025, the moment when the planet sits on the opposite side of the sky to the Sun.

Technically the planet is separated from the Sun by 180° of ecliptic longitude.

Make the most of Mars

Mars photographed by Martin Lewis
Credit: Martin Lewis

At opposition, the distance between a superior planet (those with larger orbits than Earth’s) and planet Earth is minimised for the current period of observation.

This leads to the opposition planet appearing at its largest and brightest for that period, making it the best time to observe the planet.

Chart showing the location of Mars during opposition in January 2025. Credit: Pete Lawrence
Chart showing the location of Mars during opposition in January 2025. Credit: Pete Lawrence

Will the Mars 2025 opposition be a good one?

There are a couple of caveats with the 2025 Mars opposition.

Firstly, the distance between Earth and Mars is actually at its minimal value on 12 January, four days before technical opposition.

Also, this opposition is regarded as aphelic, meaning Mars is in a position where it is nearer to the furthest point of its orbit around the Sun and hence more distant from Earth. 

At perihelion, Mars is at the closest point to us in its elliptical orbit. Aphelion is the opposite. Credit: Paul Wootton
At perihelion, Mars is at the closest point to us in its elliptical orbit. Aphelion is the opposite. Credit: Paul Wootton

The bad news here is that Mars will only reach an apparent diameter of 14.6 arcseconds in January 2025.

The good news is that it does so at a very favourable position in the sky, high in the constellation of Gemini and able to reach 62° altitude under dark sky conditions. 

In the weeks leading up to opposition you can observe different Martian features. A small scope will show the larger markings, while anything over 200mm starts to reveal more detail. In these south-up views Mars rotates right to left with the orientation shown. Credit: Pete Lawrence
In the weeks leading up to opposition you can observe different Martian features. A small scope will show the larger markings, while anything over 200mm starts to reveal more detail. In these south-up views Mars rotates right to left with the orientation shown. Credit: Pete Lawrence

Mars started January 2025 bright, shining at mag. –1.2.

It moves from Cancer into Gemini throughout the month in a westerly (retrograde) direction.

On 14 January at 04:30 UT, the Red Planet sits 26 arcminutes to the north of the full Moon’s centre.   

By the end of the month, Mars will shine at mag. –1.1 and will have an apparent diameter of 13.8 arcseconds, reaching a peak altitude of 63°. 

January 2025 is a great time to observe this interesting planet with a telescope, recording its dark surface markings, polar caps, weather and occasional dust storms.

Mars opposition 2025 quick facts

  • Best time to see: 12 January, 00:48 UT 
  • Altitude: 62°
  • Location: Gemini
  • Direction: South
  • Features: Polar caps, surface markings, weather
  • Recommended equipment: 75mm scope or larger

If you observe or photograph Mars during the 2025 opposition, share your experiences and images with us via contactus@skyatnightmagazine.com

Pete Lawrence

Astronomer and presenter

Pete Lawrence is an experienced astronomer and astrophotographer, and a presenter on BBC's The Sky at Night.
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