Mars- this is a harsh, cold world, the conditions of which are very different from those we are used to. Despite the fact that the Sun (when viewed from the surface of Mars) appears here only slightly smaller than when observed from Earth, in fact Mars is located at a distance from it, that is, much further than our planet (149.5 million km .). Accordingly, this planet receives a quarter less solar energy than the Earth.
However, distance from the Sun is only one of the reasons why the planet Mars is a cold planet. The second reason is that it is too thin, consisting of 95% carbon dioxide, and unable to retain enough heat.
Why is atmosphere so important? Because for our (and any other) planet, it serves as a kind of “thermal underwear” or “blanket” that prevents the surface from cooling too quickly. Now imagine that if on Earth, with its very dense atmosphere, in winter the temperature drops in some regions to -50-70 degrees Celsius, how cold it must be on Mars, whose blanket-atmosphere is 100 times thinner than the earth’s!
Snow on Mars - a landscape as seen by one of the rovers on the surface of the red planet. To be honest, here in Yakutia I saw exactly the same landscapes
Temperature on Mars day and night
So, Mars is a lifeless and cold planet, due to its thin atmosphere, completely deprived of the chance to ever “warm up”. However, what temperature is typically observed in Martian conditions?
Average temperature on Mars is something around minus 60 degrees Celsius. So that you understand how cold it is, here’s food for thought: on Earth the average temperature is +14.8 degrees, so yes, it’s very, very “cool” on Mars. In winter, near the poles, temperatures on Mars can drop to -125 degrees Celsius, regardless of the time of day. On a summer day, near the equator, the planet is relatively warm: up to +20 degrees, but at night the thermometer will drop again to -73. You can’t say anything - the conditions are simply extreme!
As temperatures drop, particles of carbon dioxide in Mars' atmosphere freeze and fall as frost, covering the planet's surface and rocks like snow. Martian “snow” bears little resemblance to terrestrial snow, because its snowflakes are no larger in size than red blood cells in human blood. Rather, such “snow” resembles a thin fog that settles on the surface of the planet as it freezes. However, as soon as the Martian morning comes, and the planet’s atmosphere begins to warm up, carbon dioxide will again turn into a volatile compound, and again cover everything around with a white fog until it evaporates completely.
The ice caps of Mars are visible even from the ground in a good telescope.
Seasons (seasons) on Mars
Like our planet, Mars' axis is slightly inclined relative to the plane, which in turn means that, just like on Earth, Mars has 4 seasons, or seasons. However, due to the fact that the orbit of Mars around the Sun does not resemble an even circle, but is slightly shifted to the side relative to the center (the sun), the length of the Martian seasons is also uneven.
So, in the northern hemisphere of the planet, the longest season is spring, which lasts as many as seven on Mars earthly months. Summer And autumn about six months, but the Martian winter is the shortest time of the year, lasting only four months.
During the Martian summer, the planet's polar ice cap, made mostly of carbon dioxide, shrinks significantly in size and may disappear altogether. However, even a short but unusually cold Martian winter is enough to build it up again. If there is water somewhere on Mars, then most likely you need to look for it at the pole, where it is trapped under a layer of frozen carbon dioxide.
The harsh climate of Mars is distinguished by its weather conditions, due to its thin atmosphere, unable to retain heat and the huge distance to the Sun. Compared to the Earth, it is 1.52 times further away and receives less solar heat as a result, it is very cold there.
Seasonal changes in the seasons of Mars Are there seasons on Mars?
The question of whether there is a change of seasons on Mars has long been closed. The planet's equator is located relative to the plane of its orbit at an angle; its angle is 25.19°. It is because of this deviation that the seasons change on Mars. The thing is that when Mars moves around the Sun, the direction of the axis does not change. Therefore, Mars, moving along its orbit, turns the northern hemisphere towards the sun once every 24 months, and after 12 months the southern hemisphere for an average of 5 months. During this period, the planet's hemisphere receives more sunlight, which means it warms up more, forming a warmer climate. For this reason, seasonal changes are observed, and opposite seasons are observed on the hemispheres.
Seasonal changes on Mars
If on Mars there is a change of seasons like on Earth, then there are 4 seasons. The sequence is similar to ours - winter is followed by spring, then summer, then autumn. Seasonal changes in the Martian year are uneven because the orbit has an elliptical shape, and the center of the orbit relative to the Sun is shifted to the side. So spring is the longest season on Mars, sometimes lasting up to seven months. The shortest season of the year is winter, only about four months. Summer and autumn occupy approximately six months of the year. One complete circle around the Sun takes twenty-four months.
The beginning of the season is determined through the term “solar longitude”. It denotes the angle from the imaginary line that connects the planet to the Sun on the day of the vernal equinox.
Due to the specific deviation of the axis line, the seasons on Mars are more pronounced in the southern hemisphere. Changes are most noticeable at the poles. They are covered by formations white, which scientists called polar caps. The length of such cover in the Arctic reaches 4000–6000 km by the end of the cold period. The size is affected by how low the temperature drops. At the beginning of spring, the crust begins to slowly decrease. In hot weather, its length exceeds 700–1500 km. Where the roof has shrunk, there are only small patches of ice.
The coating in the south evaporates much faster and lasts less - and in some years it practically disappears. A dark frame forms around the melted area, and nearby details become more distinct.
Not a single ice column completely disappears. The part that remains even in summer is called the “residual cap”. It represents the lowest level of the glacier, which consists of water and dust. According to researchers, the array of remains occupies a couple of hundred meters.
With the onset of heat, only the initial layer, no more than 1 m thick, comes off. It consists of frozen carbon dioxide - dry ice. It warms up and rises with evaporation into the atmosphere, and then grows again - this is how a new “cap” is formed.
To date, several ideas for Martian calendar calculation have been developed. The fundamental invention was Thomas Gangale's 1985 invention. The Dari calendar, developed by him and subsequently improved, became the most probable for the system of calculating the seasons of the red planet.
Dari calendar
It was convenient and easy to use. Each decade contains 6 years of 669 days and 4 years of 668 days. Longer years are more common than ordinary years; they are called leap years. The Dari calendar offers two options: make leap years odd numbers or in each decade put them several years one after another.
The Martian calendar is closely related to terrestrial standards. The basic unit of measurement is the sol, which lasts 24 hours and 39 minutes. According to the Dari system, the beginning falls on Sunday - Sol Solis. It is followed by other sols, which received names from objects in the Solar System.
The annual period is divided into 4 quarters of 6 months. The first five of each six have 28 days. If the year is a leap year, then the final 24th month also has 28 sols, not 27.
A new 7-day period in a month is equal to its own beginning. The last day is only omitted if the month has 27 days - this is used to maintain the order of the weekends.
According to astronomers, the error in the Dari calendar is possible by one sol in 100 years. This indicates the reliability of this timing plan.
Other calendars
The Martian theory is one of the Darisky variations, it was presented in 2002. He offers new versions of the distribution of Martian months. According to it, the months of each quarter begin on one day of the week. In an even year, the 1st quarter begins on Sunday, the 2nd on Saturday, the 3rd on Friday, and the 4th on Thursday. The months of the first 3 quarters have 42 sols each, and the 4th quarters have 41 sols. In an odd-numbered year: the first from Wednesday, the second from Tuesday, the third from Monday, the fourth from Sunday. The number of sols is similar to the even year system, the only difference is last month years 42 sol.
1st year
2nd year
Another concept of the Martian calendar proposes the following number system. A year includes the usual 12 months. The first two have 49 sols each, the third 56, the fourth and fifth 63. The longest month is the sixth, it has 66 days. Further, the amount decreases in the seventh and eighth months by 63 sols, in the ninth by 56, in the tenth and eleventh by 49 and in the last month of the year by 42 sols.
The Red Planet is the second name for Mars, which is located quite close to Earth. It is quite possible to observe the “neighbor” in the starry sky without a telescope.
Mars, belonging to the Terrestrial group, is the fourth planet from the Sun. For comparison: Earth occupies third position in our solar system.
The Red Planet is our “neighbor”
The name “red” is primarily associated with its shade.
Due to the high content of iron oxides, the color of its surface is slightly reddish. As for the Earth, it is almost twice as much. The diameter of the planet is about half that of Earth.
How long is a day on Mars?
The orbital period of Mars around the Sun is 687 Earth days. That is, a year on Mars lasts almost twice as long as on Earth.
This is due to the fact that the distance to it is 1.62 times greater than from us to the Sun, and the orbital period naturally takes longer.
How long is a day on Mars? The length of the day on Mars is quite close to Earth's. Only this planet of our solar system has this period as close as possible to us compared to the others.
Regarding the duration, a day on Mars in hours familiar to our understanding will be 24 hours 37 minutes.
This figure slightly exceeds the Earth's day. The reason for how long a day on Mars lasts is primarily the speed of rotation of the Red Planet around its axis.
Length of day on the planets of our solar system
The length of a day directly depends on the distance to the Sun and the speed of rotation around its own axis of each planet. There are sidereal and solar days.
The magnitude of the difference between them depends on a combination of two factors - these are the periods of revolution around the Sun and revolution around its axis.
Let's look at the length of a day and year on other planets and compare it with how long a day lasts on Mars and Earth.
The first and foremost is Mercury. A sidereal day is not 59 Earth days, and a solar day lasts about 176.
As for Venus, due to its revolution in the opposite direction, sidereal days have a duration of 223 Earth days, and solar days are 117 days.
The Earth has 24 hours in a solar day, the sidereal day is slightly shorter and amounts to 23 hours 56 minutes.
The length of a stellar and solar day on Mars is similar to that on Earth. And they are 24 hours 37 minutes and 24 hours and 40 minutes, respectively. That is, a day on Mars lasts 24 hours 40 minutes.
As for the giant planets, on Jupiter it is almost ten hours, on Saturn - about 10 hours 34 minutes. On Neptune it is approximately 16 hours, and on Uranus it is 17 hours and 15 minutes. The difference between solar and sidereal days on these planets is insignificant. This is due to the long period of revolution around the Sun.
As we can see, of all the planets, in terms of duration, in comparison with the Earth, Mars is the most similar.
A day on Mars, as well as on our planet, is four minutes longer than a sidereal day.
On other planets the difference is more significant; such great similarities are not observed.
A day on Mars is the same as on Earth
In 2023, it is planned that this time, unlike conventional probes exploring the planet, people will fly on board the spacecraft.
This rather complex mission is associated with the fact that living conditions for people are much more difficult than on their home planet, and going for a walk in open space is impossible without protective equipment.
One of the issues regarding the adaptation of new Martian inhabitants is the body’s reaction to how long a day lasts on Mars, in contrast to Earthly conditions.
Will there be a full-fledged biological adaptation? According to physiologists, such a small difference of 37 minutes will be quite easily perceived by the settlers.
Many difficulties are expected, but perhaps, despite Mars being so similar to ours, it will remind the astronauts of home. It’s not for nothing that the Red Planet is called Earth’s twin. Its similarity is great, but its suitability for living is minimal.
Against the backdrop of high levels of radiation, to protect the settlers, it is planned to build residential complexes specially designed to protect them from fairly harsh conditions.
There is practically no atmosphere on Mars, there is increased rarefaction. The planet's air contains mainly carbon dioxide.
As for the climate, it is quite harsh. At the equator in summer time the temperature rises to a maximum of +27 degrees Celsius.
Thanks to this, the change of seasons is similar to the usual local conditions. But still, a year on Mars is almost twice as long as on Earth and is almost 687 days.
Based on how long a day is on Mars, and from the total number of days in the Martian year, we find that the first settlers will see the Sun 668 times during the Martian year.
Astronauts of the future
In this regard, the organizers and scientists of the mission have another problem, which is technically almost solved. It is associated with the synchronization of our and Martian time. The scientific term "Sol" refers to a day on Mars, or the length of a day.
This is exactly how the new inhabitants of Mars will call their day and say that two or three sols have passed. Well, let's hope that such a grandiose mission will be successful and will open a new interplanetary era of the future.
Seasons on Mars.
From the school course on geography and astronomy, we know that the change of seasons on Earth occurs not because the Earth comes closer to the Sun or moves away from it, but because the Earth’s equator is inclined to the plane of the Earth’s orbit at an angle of 23.5 degrees. It follows from this that the earth's axis is not perpendicular, but oblique.
As the Earth moves around the Sun, the direction of the Earth's axis does not change. Its northern end is always directed towards the North Star. Therefore, moving around the Sun, the Earth turns both its northern and southern hemispheres towards the observer.
A similar picture occurs on Mars (see Fig. 2). Different hemispheres experience opposite seasons at the same time. When it is summer in the northern hemisphere, it is winter in the southern hemisphere. If it is autumn in the northern hemisphere, then it is spring in the southern hemisphere. And this is because the inclination of Mars’ equator to the plane of its orbit is approximately the same as that of the Earth, it is 24°46’. This causes seasonal changes on Mars.
It is known that the amount of heat falling on a given surface depends on the height of the Sun above the horizon. And the higher the Sun rises above the horizon, the more it warms. The different heights of the Sun above different places on the globe explain the fact that there are different thermal climate zones on Earth: hot (tropical), two temperate and two cold. In addition, every year there are cold and warm seasons. The same thing happens on Mars. Just like on Earth, there is a clear change in the times of the Martian year and seasons. A cold, harsh winter is followed by a cool spring, then a warmer summer, which gives way to a cool autumn. After it the cold winter comes again with its short days and long nights. The results of this change of seasons are clearly visible through a telescope by the melting of the polar caps. However, the significant difference here is that the orbit of Mars lies further from the Sun than the Earth’s, and its orbital speed is less than that of our planet. Therefore, the annual path of Mars is longer. This leads to the fact that the duration of Mars' revolution around the Sun is almost twice as long as Earth's: it is 687 Earth days. The year of Mars contains 669 of its own “Martian” days, which are much longer than those on Earth. Thus, the Martian year is almost twice as long (more precisely, 1.88) as long as the Earth’s.
In the summer period for the northern hemisphere of the Earth (in July), our planet is most distant from the Sun (152 million km), and in the winter (January) - less (147 million km). The difference is 5 million km. – insignificant, and therefore summers in the northern and southern hemispheres are almost equally warm. The same can be said about the winter periods. But since the eccentricity of Mars is greater, its distance from the Sun at perihelion is 206.7 million km, and at aphelion – 249.1 million km. As a result, Mars at aphelion receives one and a half times less solar energy than at perihelion. Therefore, the climate in the northern and southern hemispheres is very different. It is sharply continental. Even at the equator, after a hot day, there can be frosts at night. Mars passes through the perihelion half of its orbit faster than the aphelion half. Therefore, summer in the southern hemisphere, which falls during the perihelion period, is shorter than in the northern hemisphere, and warmer, and winter is more severe. Due to the significant eccentricity of the orbit of Mars, the duration of the seasons in different hemispheres varies significantly (Table 1).
Table 1
The length of day and night also changes depending on the season. In polar latitudes, a long day, lasting almost an entire earthly year, gives way to an equally long night. In mid-latitudes, short winter days increase as spring and summer approach and decrease again after the summer solstice.
The seasons on Mars are clearly visible on its polar caps.
Polar caps.
The north and south poles of Mars are covered by bright light formations, which, by analogy with those on Earth, are called “polar caps”.
The white cover in the northern hemisphere by the end of winter extends to latitudes 50–60° and its diameter reaches 4000–6000 km, and in summer it decreases at a speed of 10–12 (sometimes up to 100) km. per day up to a diameter of 700 - 1500 km. The southern cap melts more, and in some years disappears completely, which is explained by the eccentricity of Mars' orbit. A dark border forms around the melting cap, the adjacent parts acquire clear outlines, and this wave of improved visibility moves towards the equator at an average speed of up to 35 km. per day, and at the end of summer it even goes beyond the equator to 25° latitude of the other hemisphere. All this is very similar to what happens on Earth. Observing, for example, the Earth from the Moon for a long time, one can see a similar picture. And quite naturally the hypothesis arose that the polar caps of Mars consist of snow or ice. However, this assumption is not the only possible one. Several hypotheses have been put forward about the nature of the polar caps.
Some scientists believed it was cloud cover or fogs. Others argued that this was a salt cover, and as an example pointed to salt, which forms extensive light covers on the surface of the earth's salt marshes. Most scientists associated these caps with a layer of solid carbon dioxide - a substance known to everyone as “dry ice”. This hypothesis became relatively widespread because it was consistent with spectral studies that established the presence of carbon dioxide in the Martian atmosphere.
What amazed scientists who analyzed photographs of the southern polar cap was the apparent thickness of the white cover, reaching 80 cm. They believe that this is almost certainly frozen carbon dioxide, since there is not enough water in the atmosphere of Mars for such extensive deposits of snow or ice. Temperature measurements also support this assumption. Thus, the Mariner 7 infrared radiometer recorded a minimum temperature of –160°C and an average temperature of –118°C at the southern polar cap, which approximately corresponds to the freezing temperature of carbon dioxide at the atmospheric pressure that exists on the surface of Mars.
However, based on long-term observations from Earth, it has been established that the substance of the polar caps does not completely disappear even at temperatures close to zero. Therefore, the polar ice caps most likely include both solidified carbon dioxide and small amounts of frozen water. It is possible that there is also ice under the polar caps (in the permafrost layer).
I remember how time passed amazingly slowly as a child. I remember how during the long summer we dreamed of sliding down the ice slides, and in the endless winter of swimming in the river. With age, it became clear that on our vast planet, severe winter and hot summer, cool spring and rainy autumn coexist at the same time of year, and that it is easy, with the help of airplanes, to move to a place with the necessary weather conditions. Only in adult life do we no longer rush time and enjoy any seasonal changes: the first snow, spring flowers, summer harvests, and autumn gold.
In this regard, questions arise:
- What is associated with the change of seasons?
- Are there four seasons everywhere on our planet?
- But what about the change of seasons on other planets of our solar system?
Change of seasons
If we consider the movement of the Earth relative to the Sun, it turns out that the axis of our planet is inclined to the plane of its movement at an angle of 66.5°. It follows that at each point on the earth’s trajectory, different parts of the planet’s surface receive an unequal flux of solar heat.
The Northern Hemisphere receives maximum energy when the planet faces our star with its North Pole. During this period of the year, there is a polar day at the pole, and it is summer in the Northern Hemisphere. But at the South Pole, which is in the shadows at this time, there is a fierce polar night, and in the Southern Hemisphere it is winter.
In six months, the Earth will substitute the South Pole for the Sun, and the seasons will reverse.
Where are the four seasons observed?
The part of the globe closest to the sun is the tropics.
There, the sun's rays fall on the tropical belt at an angle of 66.5° to 90°, and summer reigns almost all year round.
The farther from the hot equator, the smaller the angle the rays fall on the Earth, reducing the solar energy flux per unit area.
The change of seasons is most clearly visible in the middle latitudes, where changes in the angle of incidence of rays and the duration of daylight hours depend on the time of year.
Seasonality goes to the Arctic into eternal winter, where summer coincides with a cold semi-annual day, and winter coincides with a fierce semi-annual night.
Seasons on the planets of the solar system
The planet Mars has almost the same angle of inclination (64.8°) to its orbit and almost the same days (24 hours 37 minutes), so the change of seasons on Mars is approximately the same as on Earth.
For other planets these parameters differ significantly. Mercury, Venus and Jupiter, one might say, have no seasons; their axes are almost perpendicular to their orbits. And the planet Uranus practically lies on its side (7.7°).
And despite the rapid change of day (17 hours), the polar night and polar day there last 42 Earth years, since the planet completes one revolution around the Sun in 84 years.
