Summer solstice on Mars’ northern hemisphere is today

Summer solstice on Mars

Earth experienced its summer solstice for the Northern Hemisphere on June 21, 2023. That’s when Earth’s north pole tilted most toward the sun, giving the Northern Hemisphere the greatest amount of sunlight and marking the arrival of summer. At the same time, the Southern Hemisphere had its shortest days and entered winter.

Mars has solstices as well. Mars’ summer solstice for the northern hemisphere arrives today, July 12, 2023. The precise moment is at 6:35 p.m. CDT (23:35 UTC).

The rotational axis and north and south poles of both Earth and Mars tilt in relation to their orbital planes. This tilt means sometimes part of the planets have more sunlight than others, and it’s what gives the planets their seasons. Earth tilts 23.4 degrees from its orbital plane, and Mars tilts 25.2 degrees.

As Guy Ottewell posted at his blog, Universal Workshop:

Mars has its northern summer solstice on July 12. That is, its north pole leans most toward the sun, so that its north polar icecap is shrunken but most in view.

Here is the space view of Mars’ orbit from page 115 of Astronomical Calendar 2023, greatly simplified by removing details except for the tracks of Earth and Mars and the arrow indicating the axis of Mars’s rotation, so that you can see why, this July, the planet’s north pole is most tilted toward the sun.

The label for Virgo the Maiden looks backward, because Guy imagines you are on Earth in the diagram, looking outward to the constellation Virgo and reading the label from the other direction.

Coming seasons on Mars

The Planetary Society has a chart of the dates of the upcoming seasons on Mars. Following this summer solstice for the northern hemisphere, Mars will have an autumnal equinox on January 12, 2024. The northern hemisphere’s winter solstice is on June 7, 2024. The spring equinox is not until November 12, 2024. And then the following summer solstice will be May 29, 2025. A year on Mars is almost as long as two years on Earth.

Bottom line: The summer solstice on Mars’ northern hemisphere occurs at 23:35 UTC on July 12, 2023. At that time, the north pole is pointed most directly toward the sun.

Via Guy Ottewell

Read more: Is there a North Star for Mars?

Read more: Mars in 2023: Fading dramatically in July