Mars at opposition 2025: Best time to see Mars

Mars at opposition

Mars reaches opposition when Earth passes between the sun and the red planet Mars.

As the sun and Mars are on opposite sides of the Earth during opposition, they appear on opposite sides, or 180° apart, in our sky.

As a result, Mars rises in the east when the sun sets in the west, reaches its highest point in the sky at midnight when the sun is below your feet, and sets in the west when the sun rises in the east.

Mars is best visible around opposition

Mars at opposition marks the best time to see the outer planet, as it’s visible throughout the night under clear skies. More precisely, it signifies the middle of the best time of the year to observe the planet.

After opposition, Mars disappears from the morning sky gradually as it rises and sets four minutes earlier each day.

So, one month after opposition, Mars rises 4*30 minutes = 120 minutes = 2 hours before sunset and sets 2 hours before sunrise.

So, three months after opposition, Mars is visible in the evening sky only as it rises 6 hours before sunset, i.e., at noon, and sets 6 hours before sunrise, i.e., at midnight.

Mars is closest, largest and brightest around opposition

Mars is closest to Earth around the time of its opposition because the sun, Earth, and Mars are all lined up in a straight line, and Mars is located on the same side of the sun as Earth around the time of its opposition.

Mars at opposition and the closest approach of Mars to Earth would occur at the same time if the orbits of Earth and Mars were perfectly circular.

Mars appears largest and brightest in our sky around the time of its opposition, as it marks the closest approach of Mars to Earth.

Mars at opposition in 2025

Mars will reach opposition on January 16, 2025, at 01:00 UTC (8 p.m. EST on January 15).

Best time to see Mars in 2025: Mars will be best visible from early to late January in 2025, when the planet rises in the east around the time of sunset and is visible all night.

Closest approach of Mars to Earth in 2025: Mars will be closest to Earth on January 12, 2025, i.e., four days before its opposition in 2025. During the closest approach, Mars will be 0.64 A.U., i.e., 96 million km away from Earth.

Brightness at opposition: At its January 16 opposition, Mars will be brightest for 2025 and will shine with a magnitude of -1.4. It will be as bright as Sirius, the brightest star in the night sky.

Disk size at opposition: At its January 16 opposition, Mars will be largest in size for 2025 and will appear 14.6 arcseconds in diameter through a telescope.

Constellation at opposition: At its January 16 opposition, Mars will be located in the zodiac constellation Gemini, the Twins.

Visibility through the naked eye: Mars is easily visible to the naked eye. It will be the brightest reddish object in the night sky around the time of its opposition.

How often does Mars reach opposition?

Our Earth’s orbit is smaller and faster than Mars’s orbit. While Earth takes about 365 days to orbit the sun, Mars takes about 687 days to do so.

Mars reaches opposition once every 26 months because it takes our Earth an average of 780 days (26 months) to catch up with Mars, i.e., to align the Sun, Earth, and Mars in a straight line.

When Mars is near its perihelion, our Earth takes longer than usual (over 26 months) to catch up with Mars because Mars travels faster in that part of its orbit (according to Kepler’s second law of planetary motion).

And when Mars is near its aphelion, our Earth takes less time than usual (a little over 25 months) to catch up with Mars because Mars travels slower in that part of its orbit.

Mars at closest opposition

If the opposition of Mars occurs near its perihelion i.e. the closest point to the sun in its elliptical orbit then it’s called the perihelic opposition of Mars or the favorable opposition of Mars.

Astronomers call this event a favorable opposition of Mars because it is closer to Earth than other oppositions. On or near the favorable opposition, Mars appears relatively bigger and brighter than other oppositions. During that time, its brightness outshines all the stars.

The favorable opposition of Mars occurs once every 15 to 17 years. The last favorable opposition of Mars was on July 27, 2018 and the next favorable opposition of Mars will be on September 15, 2035 (see chart below).

Mars at furthest opposition

If the opposition of Mars occurs near its aphelion i.e. the farthest point from the sun in its elliptical orbit then it’s called the aphelic opposition of Mars.

On or near the aphelic opposition, Mars appears relatively smaller and fainter than other oppositions.

Similar to the perihelic or favorable opposition, the aphelic opposition of Mars also occurs once every 15 to 17 years. The last aphelic opposition of Mars fell on March 3, 2012 and the next aphelic opposition of Mars will fall on February 19, 2027 (see chart below).

Dates of Mars’s opposition

Here are the dates of Mars’s opposition from 2001 to 2037, according to NASA:

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