It's New Year's Day on Mars: Mars Year 39 Begins Sep 30, 2026

On 30 September 2026, at about 08:21 UTC, Mars reaches the point in its orbit where spring begins in its northern hemisphere. By the count planetary scientists use, that moment is New Year’s Day on Mars: Mars Year 38 ends and Mars Year 39 begins.

Nothing on Mars marks it. There are no fireworks over Jezero Crater and no countdown on the dusty plains. But the moment is exact, it can be worked out to the second, and it is a good excuse for a slightly odd question: what would the Korean birth chart of a baby born right then look like?

When does Mars Year 39 begin?

Mars Year 39 begins on 30 September 2026 at 08:21 UTC, when Mars reaches a solar longitude (Ls) of 0°. The one after it, Mars Year 40, begins on 17 August 2028.

Solar longitude is the angle Mars has travelled around the sun, measured from its northern spring equinox. It is the usual way to keep track of the Martian seasons: Ls 0° is the start of northern spring, Ls 90° the start of northern summer, Ls 180° autumn and Ls 270° winter.

Why is a year on Mars 687 days long?

Mars orbits about 1.524 times farther from the sun than Earth does, so its path is longer and it moves along it more slowly. One trip around the sun takes 686.98 Earth days, a little under two Earth years.

The two numbers are tied together. For planets going around the same star, the square of the orbital period grows with the cube of the distance, so the period grows with the distance raised to the power of one and a half. 1.524 to the power of 1.5 is 1.88, and 1.88 Earth years is almost exactly 687 days.

A day on Mars is a little longer than ours, too. A Martian solar day, called a sol, lasts 24 hours 39 minutes 35 seconds, so a Mars year is 668.6 sols.

How are Mars years numbered?

Planetary scientists count Mars years from 11 April 1955, the start of Mars Year 1. The date is a convention rather than an event on Mars; it simply gives everyone who studies Martian weather and seasons the same year numbers to compare.

Each Mars year starts at Ls 0°. Mars Year 38 began on 12 November 2024, Mars Year 39 begins on 30 September 2026, and each new year arrives about 687 Earth days after the last one. On that count, 30 September 2026 is Mars’s New Year’s Day.

What does Ls 0° mean on Mars?

Ls 0° is the northern spring equinox, when the sun crosses Mars’s equator heading north. Mars’s axis is tilted about 25°, close to Earth’s own tilt, so it has seasons in much the same way.

Mars’s orbit is also noticeably oval, which makes its seasons uneven. Northern spring, which starts at this New Year, lasts about 193 sols. It is the longest season of the Martian year, because Mars is near the far end of its orbit and moving at its slowest.

What would a Korean birth chart look like on Mars?

Saju, the Korean birth chart, turns a moment into four pillars of two characters each: one pillar each for the year, the month, the day and the hour. PAL:JA’s Mars calculator builds those pillars from Mars’s own clock and calendar instead of Earth’s.

The rules carry over as directly as they can. The year turns at Ls 315°, the same point on the sun’s yearly path where the saju year turns on Earth. The month changes every 30° of Ls, the day is one sol, and the hour is one twelfth of a sol, all measured by Mars sun time at the place of birth.

What is the chart of a baby born at that moment?

A baby born at Jezero Crater (77.45°E) at the very start of Mars Year 39 would have the pillars 乙卯 (hour), 癸亥 (day), 辛卯 (month) and 辛丑 (year). The Day Master, the day’s heavenly stem that saju reads as the person, is 癸: Yin Water, which PAL:JA calls Morning Dew.

Here is what each pair means, read from hour to year, with the Korean reading of each character:

• Hour 乙卯: 🌳 Yin Wood (eul) over 🐇 Rabbit (myo). It is about 06:46 by the sun at Jezero, early morning, which is the Rabbit hour.
• Day 癸亥: 💧 Yin Water (gye) over 🐖 Pig (hae). This is the day pillar, and its stem 癸 is the Day Master.
• Month 辛卯: 💎 Yin Metal (sin) over 🐇 Rabbit (myo). Ls 0° falls in the Rabbit month, which runs from Ls 345° to Ls 15°.
• Year 辛丑: 💎 Yin Metal (sin) over 🐂 Ox (chuk). This saju year began at Ls 315°, on 8 July 2026.

Morning Dew is the quiet, perceptive form of water in saju. It is usually described as observant, gentle and good at noticing what others miss. That is a description of a type, not a forecast; in saju, the other seven characters shape how any Day Master shows up.

The baby would not be the only Morning Dew on Mars. The rover Curiosity, calculated for the moment it touched down in Gale Crater in 2012, has the same Day Master.

Why is New Year's Day on Mars different from the saju new year?

The scientists’ Mars year begins at Ls 0°, the northern spring equinox. The saju year begins 45° of Ls earlier, at Ls 315°, the Martian version of Ipchun, the start of spring in the Korean calendar.

So the baby born at this New Year is already a few months into the 辛丑 saju year. It works the same way on Earth: a baby born on 1 January still belongs to the previous saju year until Ipchun in early February.

Which parts of the Mars calendar are PAL:JA's own choice?

Two starting points are PAL:JA’s own choice, because Mars has no calendar tradition to inherit. The year that begins at the first Ls 315° of Mars Year 1 (4 December 1956) is counted as 甲子, and Mars Sol Date 0 is counted as a 甲子 day.

Move either starting point and every year or day pillar on Mars shifts along with it. Everything else in the chart, from the equinox and the Mars year numbers to the length of a sol and the local sun time, comes straight from the published formulas for Mars time.

How can I calculate my own Mars chart?

Open the Mars calculator, enter your birthplace, birth date and local birth time on Earth and a longitude on Mars, and it shows your Mars chart next to your Earth chart. To see this New Year baby for yourself, tap “Mars Year 39 baby” at the top of the calculator.

Each character comes with its picture, meaning and Korean reading, and you can save the chart as an image to share. Happy Mars Year 39.