Seasonal changes on Mars. Why is the change of seasons? On Mars there is a change of seasons

Seasons on Mars.

From the school year of geography and astronomy, we know that the change of seasons on Earth does not occur because the earth comes closer to the Sun or removed from it, but from the fact that the earth's equator is tilted to the plane of the earth orbit at an angle of 23.5 degrees. It follows from this that the earth's axis is not perpendicular, but obliquely.

When the earth is moving around the Sun direction earthly axis does not change. She is all the time directed by its northern end to the Polar Star. Therefore, moving around the Sun, the Earth turns to the observer as the Northern and South his hemisphere.

A similar picture occurs on Mars (see Fig. 2). In different hemispheres, it is simultaneously the opposite seasons. When in the northern hemisphere Summer, in South - Winter. If autumn in the northern hemisphere, then in South - Spring. And this is because the slope of the Equator of Mars to the plane of its orbit is about the same as in the earth, it is equal to 24 ° 46 '. This causes seasonal changes on Mars.

It is known that the amount of heat falling on this surface depends on the height of the sun over the horizon. And the higher the sun rises above the horizon, the stronger it warms. Different sunshine over different places of the globe explains what the earth has various heat climatic belts: hot (tropical), two temperate and two cold. In addition, every year there are cold and warm seasons. The same takes place on Mars. Just like on Earth, there is a clear change of the time of the Martian year and seasons. Behind the cold, harsh winter should be a cool spring, then a warmer summer, which is replaced by a cool fall. After it, cold winter comes again with her short days And long nights. The results of such a change of seasons are clearly visible in the telescope on the melting of polar caps. However, the essential difference here is that the orbit of Mars is lying on the sun further than the earth, and his orbit movement is less than our planet. therefore annual way Mars is longer. This leads to the fact that the duration of Mars turns around the Sun is almost twice as much as the Earth: it is 687 terrestrial day. His "Martian" day, which are much longer the earthly, year of Mars contains 669. Thus, the Martian year is almost twice (or rather in 1.88) more than the earthly.

In the summer for the Northern Hemisphere of the Earth, the period (in July), our planet is most of all removed from the Sun (152 million km.), And in winter (January) - less (147 million km.). The difference of 5 million km. - Minor, and therefore summer in the northern and southern hemispheres is almost equally warm. The same can be said about winter periods. But since the excventriysuit Mars is larger, then the removal of it from the Sun in the perigelia is 206.7 million km., And in Aflia - 249, 1 million km. As a result, Mars in Afhelia receives solar energy one and a half times less than in perichelia. And therefore, the climate in the northern and southern hemispheres is very different. It is sharply continental. Even at the equator after a hot day, at night, there may be freezing. The perihelium half of the orbit Mars passes the fastest of Afhelia. Therefore, the summer in the southern hemisphere, falling on the perihelial period, is shorter than in the northern hemisphere, and warmer, and winter and severe. Due to the significant eccentricity of the orbit of Mars, the duration of seasons in different hemispheres differs significantly (Table 1).

Table 1

Depending on the season, the duration of the day and night is changing. In polar latitudes, a long day, which continues almost a whole earthly year, is replaced as long at night. In medium latitudes, short winter days increase with the approach of spring and summer and again decrease after the summer solstice.

Seasons on Mars are well traced on its polar caps.

Polar hats.

Northern I. south Polemars cover bright bright formations, which, by analogy with earth, are called "polar caps".

White cover in the northern hemisphere by the end of winter spreads to latitudes of 50 - 60 ° and its diameter reaches from 4000 - 6000 km., And in the summer it is reduced at a speed of 10 - 12 (sometimes up to 100) km. During the day to diameter 700 - 1500 km. The southern hat makes more, and in some years it disappears completely, which is explained by the eccentricity of the orbit of Mars. A dark kime forms around the melting cap, the details adjacent to it acquire the clear outlines, and this wave of improving visibility moves to the equator at an average speed of up to 35 km. per day, and the end of the summer comes even for the equator to 25 ° latitude of another hemisphere. All this is very similar to what is happening on Earth. Watching, for example, for a long time Earth from the moon, you can see a similar picture. And it was quite natural to arise the hypothesis that the polar hats of Mars consist of snow or ice. However, this assumption is not the only possible. A few hypotheses were expressed about the nature of polar hats.

Some scientists believed that it was cloudy cover or fog. Others argued that it was salt cover, and as an example was pointed to salt, which forms extensive light covers on the surface of the earth salt marshes. Most scientists bind these caps with a layer of solid carbon dioxide - substances, all known as "dry ice". This hypothesis has received relatively widespread, since it corresponded to the data of spectral studies, with which the presence of Mars in the atmosphere carbon dioxide.

That I was amazing scientists who analyzed photos in the southern polar cap, so this is the visible thickness of white cover, reaching 80 cm. They believe that it is almost certainly a frozen carbon dioxide, because in the atmosphere of Mars there is no sufficient amount of water for such extensive deposits of snow or ice. Temperature measurements are also said in favor of such an assumption. Thus, the infrared radiometer "Mariner - 7" registered in the southern polar cap the minimum temperature of -160 ° C, and the middle -118 ° C, which roughly corresponds to the freezing temperature of carbon dioxide, while atmosphere pressurewhich exists at the surface of Mars.

However, according to many years of observations from the Earth, it was established that the substance of polar caps does not completely disappear even at temperatures close to zero. Therefore, most likely the polar caps include both cultural carbon dioxide and a small amount of frozen water. It is possible that under the polar caps (in the layer of permafrost) there are also ice.

Mars - it's harsh cold worldThe conditions on which are very different from usually. Despite the fact that the sun (when looking from the surface of Mars) seems here only a little less than when observing the Earth, in fact, Mars is from it at a distance, that is, much further than our planet (149.5 million km .). Accordingly, the solar energy is obtained by this planet for a quarter less than the earth.

However, the distance from the Sun is only one of the reasons why Planet Mars is a cold planet. The second reason is too thin, consisting of 95% of carbon dioxide, and unable to keep sufficient heat.

Why is the atmosphere so important? Because for our (and any other) planet, it serves as a kind of "thermal power", or a "blanket", which prevents too fast cooler surface. Now imagine that if on Earth, with her very tight atmosphereIn winter periods, the temperature drops in separate regions to -50-70 degrees Celsius, how cold should be on Mars, whose blanket-atmosphere thinned 100 times!

Snow on Mars - landscape, as he saw him from the rover on the surface of the Red Planet. Honestly, we have observed in Yakutia exactly the same landscapes

Temperature on Mars day and night

So, Mars is a lifeless and cold planet, due to a fine atmosphere, completely devoid of a chance someday "warm up". However, what temperature is usually observed in Martian?

Middle temperature on Mars This is something about minus 60 degrees Celsius. So that you understand how cold it is, then here is food to think: on Earth, the average temperature is +14.8 degrees, so yes, on Mars, very and very "cool." In winter, in the area of \u200b\u200bthe poles, the temperature on Mars can descend to -125 degrees Celsius, regardless of day. Summer day, near the equator, on the planet is relatively warm: up to +20 degrees, however, the thermometer will fall back to -73 at night. You will not say anything - the conditions are simply extreme!

With a drop of temperature, carbon dioxide particles in the atmosphere of Mars freeze and fall out in the form of it, covering the surface and cliffs of the planet like snow. Martian "Snow" little reminds of earthly, because its snowflakes in size do not exceed the size of erythrocyte cells in human blood. Rather, such "snow" resembles a discharged fog, settling on the surface of the planet as it freezes. However, as soon as the Martian morning comes, and the atmosphere of the planet will begin to warm up, carbon dioxide will turn into a volatile connection, and again covers everything around the white fog until it turns completely.

Ice caps of Mars in a good telescope are visible even from the ground

Seasons (seasons) on Mars

As with our planet, the axis of Mars is somewhat inclined relative to the plane, which in turn means that as well as on earth, there are 4 seasons on Mars, or the season. However, due to the fact that the orbit of Mars around the Sun resembles a non-smooth circle, but somewhat shifted towards the center (Sun), the length of the Martian seasons is also uneven.

So, in the northern hemisphere of the planet, the longest season is springwhich lasts on Mars as seven earth months. Summer and fall about six months, but Martian winter - The shortest season, and lasts only four months.

During the Martian summer, the polar ice cap of the planet, consisting mainly carbon dioxide, significantly decreases in size and can completely disappear. However, even a short, but unusually cold Martian winter is enough to increase it again. If somewhere on Mars and there is water, then you most likely look for it on the pole, where it is trapped under the layer of frozen carbon dioxide.

The stern climate of Mars is distinguished by its weather conditions, is due to a thin atmosphere, unable to retain heat and a huge distance to the sun. In comparison with the Earth 1.52 times further, respectively and sun heat Gets less as the result is very cold there.

Is there a mars of seasons?

The question is whether the change of seasons is observed on Mars, has long been closed. The planet's equator is located relative to the plane of its orbit under the tilt, its angle is 25.19 °. It is because of such a rejection and a change of seasons at Mars. The thing is that when moving Mars around the Sun, the axis direction does not change. Therefore, Mars, moving in orbit, turns once every 24 months to the North Sun, and after 12 months the southern hemisphere on average for 5 months. During this period, the hemisphere of the planet gets more sunlightSo, it warms more, forming a warmer climate. For this reason, seasonal changes are traced, and the opposite times of the year are observed on the hemispheres.

Seasonal changes on Mars

If Mars has a change of seasons as on earth, then there are 4 seasons there. The sequence is similar to ours - in winter spring is coming, then summer, then - autumn. Seasonal changes in the Martian year are uneven because the orbit has an elliptical form, and the center of the orbit regarding the Sun is shifted to the side. So spring is the longest time of the year on Mars, it continues sometimes up to seven months. The shortest time of the year is winter, just about four months. Summer and autumn occupy approximately six months a year. One full circle around the Sun flows in twenty-four months.

The beginning of the year is determined through the term "solar longitude". It denotes an angle from an imaginary line that connects the planet with the sun on the day of the spring equinox.

Due to the specific dodge of the axis axis line on Mars, brighter appears in the southern hemisphere. Mostly noticeable changes on the poles. They are covered by education white colorwhich scientists called polar caps. The length of such cover in the Polar region to the end of the cold period reaches 4000 - 6000 km. The size affects how low the temperature is lowered. At the beginning of the spring, the crust begins to slowly decrease. In the heat of its length exceeds 700 - 1500 km. Where the shelter cringed, there are only small areas of ice.

The coating in the south evaporates much faster and persisted less - and in some years it almost disappears. A dark framing is formed around the monster area, and nearby parts acquire more distinct outlines.

No icy stratum disappears completely. A part that lies even in a summer time is called the "residual hat." She is the most lower level Glacier, which consists of water and dust. According to researchers, the residual array takes a couple of hundred meters.

With the onset of heat, only the initial layer with a thickness of no more than 1 m is departed. It includes frozen carbon dioxide - dry ice. It warms up and rises with evaporation into the atmosphere, and then increasing again - the new "hat" is formed.

To date, a few ideas of Martian calendar have been developed for today. The invention of Thomas Gangale 1985 was the fundamental. The Darius calendar developed by them and further improved, became the most likely for the year of the year of the year of the Red Planet.

Darisky calendar

It was distinguished by convenience and ease of use. Each decade contains 6 years to 669 days and 4 years to 668 days. For more than last year, there are more often than ordinary they are called leaps. The Darisian calendar offers two options: make leap years odd or in every decade to put them for several years one after another.

Martian calendar is closely connected with earthly standards. The main unit of measurement sol, the duration of which is 24 hours 39 minutes. According to the Darisian system, the beginning falls on Sunday - Sol Solis. It is followed by other salts that got the names from the objects of the solar system.

Annual period is divided by 4 blocks to 6 months. In the first five of each six for 28 days. If the year is leap, then in the final 24th month, there are also 28 hots, and not 27.

The new 7-day one in the month is equal to its own beginning. The last day is descended only if in a month 27 days is used to maintain the order of the weekend days.

According to astronomer estimates, the error in the Darisian calendar is possible in one Sol for 100 years. This speaks about the reliability of this time schedule.

Other calendars

Martian's theory is one of the variations of Darisky, it was presented in 2002. It offers new versions of the distribution of Martian months. According to him, the months of each quarter begin with one day of the week. In the even year, the 1st quarter begins from Sunday, 2nd from Saturday, 3rd from Friday, 4th from Thursday. In the months of the first 3 quarters of 42 Sola, in the 4th 41th. In an odd year: the first from the Wednesday, the second from Tuesday, the third from Monday, the fourth from Sunday. The number of soles is similar to the system of even years, the only difference in the last month of the year 42 Sola.

1st year

2nd year

Another concept of the Martian calendar offers the following calculus system. The year includes the usual 12 months. In the first two to 49 strains, in the third 56, in the fourth and fifth 63. The longest month of the sixth, in it 66 days. Further, the number decreases in the seventh and eighth months of 63 SIL, in ninth 56, in the tenth and eleventh to 49 and in the last month of 42 Sola.

The change of seasons on Mars is happening in the same way as on Earth. Brighter than all seasonal changes are manifested in the polar regions. IN winter time Polar caps occupy a significant area. The border of the northern polar cap can be removed from the pole by a third of the distance from the equator, and the border of the southern cap overcomes half of this distance. This difference is caused by the fact that in the northern hemisphere the winter comes when Mars passes through the perigels of his orbit, and in South - when through the aphelius (i.e. during the maximum removal from the Sun). Because of this, winter in the southern hemisphere is colder than in the North.

With the onset of spring, the polar hat begins to be eaten, leaving the gradually disappearing glasses of ice. Apparently, none of the hats disappears completely. Prior to the start of research of Mars, with the help of interplanetary probes, it was assumed that its polar regions were covered with frozen water. More accurate studies found in the composition martian ice Also frozen carbon dioxide. In the summer he evaporates and enters the atmosphere. Winds carry it to the opposite polar cap, where it freezes again. This cycle of carbon dioxide and different sizes of polar caps explains the impermanence of pressure of the Martian atmosphere. In general, the surface it is approximately 0.006 pressure of the earth's atmosphere, but may rise to 0.01.

"... In addition, they opened two little stars, or two satellites, appealing near Mars. The nearest one was removed from the center of this planet to the distance equal to three diameters, the second is from it at a distance of five of the same diameters. " These are rows from the novel Jonathan Swift about the adventures of Gullyer, they were written in 1726, when nobody saw Mars's companions even to telescopes, not to mention that quite accurately predict the parameters of these heavenly Tel. So, the period of treatment of one of the satellites of Mars Swift guess up to one quarter, and another - up to 40 percent.

By the way, Swift was not the only great writer of the XVIII century, who "opened" satellites of Mars. Francois Marie Voltaire - the ruler of the Dumus of the Brilliant Age of Education, Compounding in 1752 fantastic story "Micromegas", also mentioned the "two mons of Mars". But a glimpse, without the details that Swift listed, the only "proof" is such a consideration: one moon would not have enough to light up the planet so far from the Sun!

However, to a genuine, and not "scientific fiction" opening of Mars's satellites, humanity had to be waiting for another one and a half years, until 1877, which became truly "Martian". Giovanni Skiaparelli at that time literally put on the feet of the whole astronomical world, saying on the existence on the red planet "Channels" and "Seas". This "Martian HOT" had both an objective basis: 1877th was the year of the Great confrontation, in which Mars and the Earth are very close to each other. Such favorable conditions could not neglect the experienced astronomer Esaf Hall (1829-1907), who had already deserved a considerable authority as one of the best observers and computers in the Harvard Observatory and Professor of Mathematics in the Maritime Observatory (Washington), which also belongs to the discovery of two Martian Longs.

Having learned about the opening of the newspapers, one English schoolgirl suggested a hall of the name for new celestial bodies: the God of war in the ancient myths always accompanies his children - fear and horror, so let the inner satellites are referred to as Phobos, and the external daimos, because so these words sound in ancient Greek Language. The names turned out to be successful and fixed forever.

mars Planet Probe Satellite

So Spring came. With the fields came gray and sad snow, and the sun was warmer and gentle. Nature awakens: the first greens begins to break through, the kidneys are swelling and blooming and the kidneys on the trees, migratory birds are returned, and from the holes and nests are chosen. Soon the summer will come, autumn, winter and the spring will come again. From year to year on our planet, seasons are replaced.

But what provides these cyclic changes in nature? The main reason for changing the seasons of the year is the inclination of the axis of our planet relative to the plane of the ecliptic, i.e. The plane of the earth rotation around the sun. The axis of the Earth is inclined from the plane of the ecliptic by 23.44 °. If this angle was equal to zero, the planet would never have been replaced by seasons, the duration of the day and night would be the same, and the sun would rise above the horizon for the same height during the whole year.

And whether the seasons are replaced on other planets of the solar system?

Mercury

If we take into account only the indicator that has a decisive effect on the formation of the time of the year on Earth, the inclination of the axis of rotation, then in Mercury should not be familiar to us by the time of the year. However, Mercury moves along a very elongated orbit, approaching the perichelia to the Sun by 46 million km and extending 70 million km in Aflia, which makes a noticeable impact in the formation of Mercurian weather. Being a small distance from the Sun, the illuminated side of Mercury is heated on average to + 300 ° C (maximum: +427 ° C) and Mercurian summer comes. In the far stretch of the orbit, winter comes, even during the day at this time the temperature does not rise above 107 ° C, and at night it drops to -193 ° C.

Dawn on Mercury occurs only once every two years (once in 176 days), but this is the hottest dawn throughout the system.

At the same time, the pole of Mercury practically does not enter the sunlight due to the minimum inclination of the axis of rotation to the ecliptic plane (0.01 °). In these dark and cold areas, ice polar caps were found, though reaching only 2 meters in thickness.

Interestingly, the day (175.94 of the earthly day) on Mercury last twice as a year (87.97 terrestrial days).

On Venus, as in Mercury, there is also no change of the year. The angle of rotation axis of Venus is impressive 177 °, in other words, this planet has an inverted orientation, and the actual inclination angle is only 3 °. Eccentricity orbit, i.e. Its degree of deviation from the circle is extremely small (0.01) and therefore does not contribute to any adjustment in the weather. All year round on the surface of the planet reigns a hot summer: the average temperature exceeds the mark + 400 ° C.

All year round in Venus, sultry heat reigns, the average temperature is about + 400 ° C.

Mars

Mars is largely similar to our planet. The slope of the axis of rotation of Mars relative to the plane of its orbit is 25.2 °, which is only a little more terrestrial. A little bigger and the eccentricity of the orbit of the Red Planet. As a result, the Martian climate is a bit more pronounced seasonal nature, in other words, the difference (especially in temperature) between different times of the year is stronger.

Another interesting feature of the Martian seasons is that they significantly differ in different hemispheres of the planet. So in the southern hemisphere there is a hot summer and a cold winter, whereas in the northern there are no such contrasts - and summer and winter are soft here.

Jupiter

The axis of rotation of the planet giant is inclined only 3.13 ° with respect to the plane of the orbit, the degree of deviation of the orbit itself from the circle is also minimal (0.05). In other words, nothing here climate is of a seasonal nature and constant throughout the year.

Saturn

The slope of the axis of rotation of the Saturn is 29 °, so the change of seasons on this planet is characterized by more pronounced drops in the amount of sunlight, and therefore the temperature than on the ground. Every season - whether summer or autumn lasts on the planet-giant about 7 years. Depending on the time of year, Saturn can change its colors. Eight years ago, when the AMC "Cassini" first approached the planet for the first time, in the northern hemisphere was winter and this part of Saturn had a blue hue. To date, the south is painted in blue - winter came there. According to astronomers, this phenomenon arises due to the intensity of radiation of the ultropiolet - in the winter it decreases, with the arrival of summer - rises.

Winter on the southern hemisphere Saturn. The blue haze, which covered the southern pole of the planet is a direct consequence of lowering the temperature, i.e. Winter arrival. 10 years ago, in 2004, exactly the same Blue fog watched north Pole Gaza giant.

Uranus

The angle of inclination of the planet rotation axis is 97.86 ° - in other words, Uranus lies on the side slightly downwards. This factor explains quite a specific change of seasons. During the periods of solstice, only one of the poles of the planet is facing the sun. The usual change of day and night is characteristic only for the equator, the rest of the uranium are under the cover of a polar day or polar night of 42 years old.

Photo of uranium made by probe Voyager-2

On the pole converted to the sun, cardinal changes occur: the temperature increases significantly, the upper layers of the atmosphere begin to slowly acquire bright colors, replacing the pale blue shade, the wind speed and the number of clouds increases.

Neptune

At Neptune, the axis of rotation is rejected by 30 °, so the change of seasons here is similar to earthly, but its adjustments make the distance of the planet to the Sun. The year at Neptune is almost 165 terrestrial years, therefore it lasts every season, no longer less than, 41 years! In 2005, summer began on the southern hemisphere, and it will last until 2046.