Mars, the fourth planet in the solar system, has captured the imagination of scientists, writers, and dreamers alike. From its barren, reddish landscapes to its mysterious moons, this neighboring planet has been the subject of much exploration and study. But have you ever wondered how time is measured on Mars?
The Martian Year
Martian Year 1 began on April 11, 1955following a major global dust storm that occurred on Mars during this period. This storm occurred when it was already 1956 on Earth. Unlike the Gregorian calendar, where January 1st marks the beginning of the year, the Martian year begins on the spring equinox in the northern hemisphere (or the autumn equinox in the southern hemisphere).
On Mars, months are not used in the calendar as they are on Earth.. Instead, solar longitude (Ls) is used, which measures the angle Mars has traveled in its orbit since the beginning of the year, as seen from the Sun.
The Martian year begins at Ls 0ºwhich corresponds to the spring equinox of the Northern Hemisphere. The summer solstice of the Northern Hemisphere occurs at Ls 90º, the autumn equinox at Ls 180º and the winter solstice at Ls 270º.
The influence of gravity and the atmosphere
The way we perceive time is not only related to the cycle of the day, but also to gravity and the atmosphere. Mars has about 38% of Earth’s gravitymeaning any activity that requires physical exertion can feel different. While gravity doesn’t change the measurement of time per se, it can affect how astronauts experience the passage of time in their daily lives. Additionally, the Martian atmosphere is much thinner than Earth’s, meaning weather conditions are extreme. Dust storms and fluctuating temperatures can affect the perception of time, making outdoor activities more difficult and time-consuming.
A day on Mars
A sidereal day on Mars lasts approximately 24 hours, 37 minutes, and 22.663 seconds. Meanwhile, a solar day, called the “sun,” lasts 24 hours, 39 minutes, and 35.24409 seconds. All this means that The Martian solar day is about 2.7% longer than the Earth day..
For space missions that landed on Mars, a 24-hour “Martian clock” was used. In this, Each hour, minute and second is 2.7% longer than their equivalents on Earth.
Missions like Mars Scout, Mars Exploration Rover, phoenix And Science Lab on Mars They worked on “Martian time,” adjusting their schedules to the local time at the landing site. This This represents a daily shift of approximately 40 minutes from Earth time.The teams on these missions used clocks adapted to Mars time instead of Earth time.
Local solar time is crucial for planning Mars probe activitiesThis is partly because solar panels rely on daylight. Mars experiences rapid temperature fluctuations between sunrise and sunset, due to the lack of a dense atmosphere to buffer these changes.
The calendar on Mars
A year on Mars, also called a “sidereal year,” lasts 668.5991 suns. This is equivalent to approximately 686.98 Earth days.. Due to the eccentricity of its orbit, Martian seasons are not of uniform length.
On Earth, however, months are based on the lunar cycle. However, Mars has two moons: Phobos and Deimos.; The orbital periods of these moons are too short to use a system similar to Earth’s.
For this and other reasons, THE Planetary Society decided not to use a fixed calendar on Mars. Instead, the Sun’s planetocentric longitude, known as Ls, is used to mark Mars’ position in its orbit.
The values of Ls correspond to seasonal events, as follows:
- Ls = 0° for the spring equinox in the Martian northern hemisphere.
- Ls = 90° for the northern summer solstice.
- Ls = 180° for the northern autumn equinox.
- Ls = 270° for the northern winter solstice.
In this system, as we saw at the beginning Martian Year 1 (MY1) began on April 11, 1955 and ended on February 26, 1957.coinciding with a global dust storm on Mars. The dust storm cycle on Mars begins after perihelion, the closest point to the Sun in the Martian orbit.
Subsequently, Martian Year 0 (MY0) was defined, which began on May 24, 1953. Previous years are numbered with a negative sign.For example, MY-1 began on July 7, 1951, and MY-2 on August 19, 1949. The first observation of Mars with a telescope by Galileo, in late 1610, was at MY-183.
Conclusion
Mars missions also raise interesting questions about how humans will experience time in a different environment. Will our sense of time adapt to Martian conditions? Will time feel faster or slower in a world with different sunlight and gravity? These are questions that, while abstract, can have a real impact on the lives of astronauts.
Recommended Readings
Seasons on Mars
Mars, astrobiological target
