Seasons on Mars

Mars has solstices and equinoxes just like Earth. They're associated with seasons on the red planet, just like on Earth. However, Martian seasons are very different. The atmosphere on Mars is very thin and contains a different blend of gases. Mars also has a more elliptical orbit causing the planet's distance from the sun to vary much more. These cause temperatures to rise and fall through a bigger range of temperatures than on Earth. However, most of Mars stays far colder than most of Earth. Earth's northern and southern hemispheres have climate differences largely driven by more of the ocean mass being south of the equator. Hemispheric climate differences on Mars are largely driven by the planet being so much farther from the sun during part of its orbit.

On Mars, the northern hemisphere spring lasts seven Earth months. Summer lasts six months, fall lasts five months, and winter lasts four months. The seasons vary in length so much because the planet is in the slowest part of its orbit in the spring and summer and the fastest in the fall and winter. The opposite is true for the seasons in the southern hemisphere where winter is longer than summer.

For centuries, astronomers have watched the polar ice caps on Mars grow and shrink. As the pole that has been tilted away from the sun returns to sunlight, a large white area appears. It shrinks and disappears as that pole continues to tip toward the sun. The Martian polar ice caps are made partly of water ice and partly of frozen carbon dioxide. The carbon dioxide is permanent in the southern Martian polar cap but gets warm enough to evaporate at the planet's north pole leaving water ice behind.

Here are when the equinoxes and solstices on Mars occur from 2020 through 2039.