In this article, you will learn what “sol” is in the movie “The Martian,” and what is the meaning of this word.
Movie production
The movie "Martian" was shot based on the novel of the same name by Andy Weir. It belongs to the genre of so-called solid science fiction, and some of the events described here are happening now, others may happen in the foreseeable future.
Plot
So, in the courtyard of the 2030s, NASA carries out regular manned missions to Mars. Another of them, "Ares-3", is located on the red planet and finishes performing scientific tasks. Astronauts are preparing to soon recover home on the interplanetary spacecraft Hermes. In the movie “The Martian” they write sol, indicating the days of the scientific mission on the red planet, at the beginning of the storyline 19 of them passed.
The weather plans make adjustments to the astronauts. The storm begins, it is able to overturn the take-off module. It is urgent to leave the planet so that everyone here does not die. One astronaut (Mark Watney, whose role is played by Matt Damon) is knocked down by equipment flying from gusts of wind and carried away from a residential module, he is lost in a hurricane, and his biomonitor shows zero vital signs. The crew of the mission, believing that he is dead, decides to fly without him. They return to the Hermes in Martian orbit and head to Earth.
Immediately you need to point out the miscalculation of the scriptwriters in this scene. The atmosphere on Mars is so rarefied that even the strongest storms here will not be able to budge and chair. Naturally, the local gust of wind will not be able to carry away a large object or person in a spacesuit.
But Watney survives after the hurricane. Left alone on Mars, wounded, he begins the struggle for survival. Having pulled out a piece of equipment and sewing up the wound, Mark makes the first entry at 6 hours 53 minutes of the 19th sol in the video diary: “I will not die here!” Subsequently, all timing is carried out in sols.
So what is “sol” in the movie “The Martian”? Surely every viewer asked himself this question.
Colonizer
The Ares-3 mission was planned for 31 sols, and food reserves were taken for 68 solos for six people. Mark, having carried out a food audit, found that it was enough for 300 solos. If you save, you can stretch to 400 solos. However, food is needed for 3 years, before the arrival of the next expedition.
Fortunately, he is a nerd and decides to grow his own food. On a planet where nothing grows.
The following is a description of his agricultural efforts to cultivate potatoes. On the 31st sol, he equips the beds with Martian soil. To get a crop for every cubic meter of soil, you need 40 liters of water. What is “sol” in the movie The Martian is not too clear yet. From the 48th sol, Mark is preoccupied with getting water, he gets it by burning rocket fuel. The first shoots appear on the 50th salt, on the 79th - it's time to harvest. Questions for The Martian “What Does Sol Mean?” getting bigger.
To reconnect with Earth, Mark uses the old Pathfinder descent vehicle, which has been on the red planet since 1997.
During his long stay in complete solitude on the whole planet, Watney, ironically, often reflects that he is the only colonizer here. According to international laws, all Mars belongs to him, because he was the first to grow crops here.
Having solved the food problem and having established a channel of communication with NASA specialists, Mark begins, under their leadership, to implement his evacuation plan from Mars. NASA decided not to tell the Hermes crew returning home that Mark Watney survived so as not to destabilize the situation on board. However, the colonialist emphatically insisted on being told about this.
Crew
Suddenly, there is a depressurization of his greenhouse, and the entire crop perishes. The astronaut has 912 solos left, and a truck with food from Earth will arrive at the 868th sol, provided that everything works out.
What is "sol" in the movie "Martian", most viewers are still not known for certain. But at launch, the rocket crashes. It will take so much time to assemble a new probe that Mark simply will not live to see his arrival.
The Chinese space agency comes to the rescue. It is ready to deliver its finished probe with all the necessary into orbit. It remains only to deliver it to Mars.
The Hermes crew presents NASA with an ultimatum: they pick up a Chinese probe in orbit, go around the Earth and rush back to Mars. Plus seven months to an already super-long space mission. But they are ready to sacrifice everything for their friend.
His colleagues who left him on Mars become his saviors.
The way home
Mark can only go on a journey along Mars to the Schiaparelli crater, where the Ares-4 take-off module is located, and go into orbit on it, where Hermes will take it.
His journey on the red planet begins at the 461st sol. On the 538th sol, the astronaut arrives in the coveted crater. The 561st sol is the start day. The riddle, which means the word "sol" in the movie "Martian", is becoming more intriguing.
Let us open the veil of secrecy.
Exploration of Mars. Our days
When in recent decades, NASA carried out scientific missions with descent vehicles to the surface of the red planet, the working hours of these expeditions were synchronized with local time on the landing site on Mars, and not with standard Earth time.
When designing spacecraft launched to the surface, an approach is used when the time of a Martian sunny day is divided into 24 hours, in which hours, minutes and seconds are 2.7% more than Earth's.
Because, if this is not done, the mission time deviates upwards by forty earth minutes every day. So, the scientific team of Mars Exploration Rover, during which the Spirit and Opportunity research descent vehicles (rovers) were brought to the surface of Mars in 2004, wore wrist watches tuned for Martian time.
Why is it necessary
Knowing the exact local Martian time is absolutely necessary for planning the activities of rovers, because they are charged by solar panels and depend on the time of sunrise and sunset.
In addition, it is necessary to take into account the temperature jumps when day and night change, which are very significant on Mars, because the atmosphere here is very sparse, and there are no oceans to compensate for these phenomena on Earth on the red planet.
At one time, various standards for calculating time on this celestial body were developed. These include the metric system with its millimeters and centids, the “extended day” system, when all hours were equal to the standard earth, but the last hour of the day was 24 hours 39 minutes and 35 seconds.
But none of them, NASA, which is the leader in the remote exploration of Mars today, has not taken advantage.
The generally accepted unit of measurement of time on Mars eventually became sol.
What does sol mean in the movie The Martian?
The average length of a Martian sidereal day, that is, the time of a full revolution of the red planet around its axis relative to the stars, is 24 hours 37 minutes 22.663 seconds. The length of its sunny day (or simply sol), that is, the time of a complete revolution of Mars around its axis relative to the Sun, is 24 hours 39 minutes 35.244147 seconds.
Thus, 1,0274912517 earth days fit in one salt. Martian day, 2.7% longer than Earth
By the way, for the Earth these figures look as follows: a sidereal day lasts 23 hours 56 minutes 4.0916 seconds, and a sunny day - 24 hours 00 minutes 00.002 seconds.
NASA is now using the following method for timekeeping on Mars: when the descent spacecraft begins its mission on the surface of the red planet, passing sols are counted by a simple numerical count.
Therefore, there are no months and years here, only salts having their own ordinal numbers.
So, for example, the countdown of the Spirit and Opportunity rovers that landed in a pair was not synchronized. Although they were sent for simultaneous work on Mars, everyone considered Sol 1 to be the date of their landing. In addition, their location is 179 degrees apart on a planetary scale, so when one day had another, they had night and they performed their tasks independently of each other.
The days in the movie The Martian were counted in the same way. What sol means, now we know.
Simply put, sol is a Martian day. We are witnessing the birth of a new, previously unprecedented system of chronology, which is based on the cosmological cycles of another planet. And this, unlike the events in the film, is happening right now.