What is the temperature on mars. Temperature on the planets of the solar system. Seasons on Mars

The planet Mars has an equatorial diameter of 6787 km, i.e. 0.53 of the Earth's. The polar diameter is somewhat less than the equatorial one (6753 km) due to the polar compression equal to 1/191 (against 1/298 near the Earth). Mars rotates on its axis in much the same way as the Earth: its period of rotation is 24 hours. 37 min. 23 seconds, which is only 41 minutes. 19 sec. more period rotation of the earth. The axis of rotation is inclined to the plane of the orbit at an angle of 65°, almost equal to the angle of inclination of the earth's axis (66°.5). This means that the change of day and night, as well as the change of seasons on Mars, proceed in almost the same way as on Earth. There is also climatic zones terrestrial: tropical (latitude of the tropics ± 25 °), two temperate and two polar (latitude polar circles±65°).

However, due to the remoteness of Mars from the Sun and the rarefaction of the atmosphere, the climate of the planet is much more severe than that of the earth. The year of Mars (687 Earth or 668 Martian days) is almost twice as long as the Earth, which means that the seasons last longer. Due to the large eccentricity of the orbit (0.09), the duration and nature of the seasons of Mars are different in the northern and southern hemispheres of the planet.

Thus, in the northern hemisphere of Mars, summers are long but cool, and winters are short and mild (Mars is close to perihelion at this time), while in the southern hemisphere, summers are short but warm, and winters are long and severe. On the disk of Mars in the middle of the XVII century. dark and light areas were seen. In 1784

V. Herschel drew attention to seasonal changes in the size of white spots near the poles (polar caps). In 1882, the Italian astronomer G. Schiaparelli compiled detailed map Mars and gave a system of names for the details of its surface; highlighting among the dark spots "seas" (in Latin mare), "lakes" (lacus), "bays" (sinus), "swamps" (palus), "straits" (freturn), "sources" (fens), " capes" (promontorium) and "regions" (regio). All these terms were, of course, purely conventional.

The temperature regime on Mars looks like this. In the daytime around the equator, if Mars is near perihelion, the temperature can rise to +25°C (about 300°K). But by evening, it drops to zero and below, and during the night the planet cools even more, since the rarefied dry atmosphere of the planet cannot retain the heat received from the Sun during the day.

The average temperature on Mars is much lower than on Earth - about -40 ° C. Under the most favorable conditions in the summer in the daytime half of the planet, the air warms up to 20 ° C - quite an acceptable temperature for the inhabitants of the Earth. But winter night frost can reach up to -125 ° C. At winter temperatures, even carbon dioxide freezes, turning into dry ice. Such sharp temperature drops are caused by the fact that the rarefied atmosphere of Mars is not able to retain heat for a long time. The first measurements of the temperature of Mars using a thermometer placed at the focus of a reflecting telescope were carried out as early as the early 1920s. W. Lampland's measurements in 1922 gave average temperature surface of Mars -28°C, E. Pettit and S. Nicholson received in 1924 -13°C. A lower value was obtained in 1960. W. Sinton and J. Strong: -43°C. Later, in the 50s and 60s. numerous temperature measurements were accumulated and summarized at various points on the surface of Mars, in different seasons and times of day. From these measurements, it followed that during the day at the equator the temperature can reach up to +27°C, but by morning it can reach -50°C.

The Viking spacecraft measured the temperature near the surface after landing on Mars. Despite the fact that at that time it was summer in the southern hemisphere, the temperature of the atmosphere near the surface in the morning was -160°C, but by the middle of the day it rose to -30°C. The pressure of the atmosphere at the surface of the planet is 6 millibars (i.e. 0.006 atmospheres). Above the continents (deserts) of Mars, clouds of fine dust constantly rush, which is always lighter than the rocks from which it is formed. Dust also increases the brightness of the continents in the red rays.

Under the influence of winds and tornadoes, dust on Mars can rise into the atmosphere and stay in it for quite some time. Strong dust storms were observed in the southern hemisphere of Mars in 1956, 1971 and 1973. As shown by spectral observations in infrared rays, in the atmosphere of Mars (as in the atmosphere of Venus) the main component is carbon dioxide (CO3). Long-term searches for oxygen and water vapor at first did not give reliable results at all, and then it was found that oxygen in the atmosphere of Mars is no more than 0.3%.

The planet Mars, like another close neighbor of the Earth, Venus, has been exposed to the most scrutiny astronomers. Visible to the naked eye, since ancient times it has been shrouded in mystery, legends and conjectures. And today we know far from everything about the Red Planet, however, many of the information obtained over centuries of observation and study dispelled some myths and helped a person understand many of the processes taking place on this cosmic object. The temperature on Mars, the composition of its atmosphere, the features of orbital movement after the improvement of technical methods of research and the beginning space age managed to move from the category of assumptions to the rank indisputable facts. Nevertheless, much of the data about both such a close and such a distant neighbor has yet to be explained.

Fourth

Mars is located one and a half times farther from the Sun than our planet (the distance is estimated at 228 million km). According to this parameter, he takes the fourth place. Beyond the orbit of the Red Planet lies the main asteroid belt and the "possession" of Jupiter. It flies around our star in about 687 days. At the same time, the orbit of Mars is strongly elongated: its perihelion is located at a distance of 206.7, and aphelion - 249.2 million km. A day lasts here only almost 40 minutes longer than on Earth: 24 hours and 37 minutes.

little brother

Mars belongs to the terrestrial planets. The main substances that make up its structure are metals and silicon. Among similar objects in its dimensions, it is only ahead of Mercury. The diameter of the Red Planet is 6786 kilometers, which is about half that of the Earth. However, in terms of mass, Mars is 10 times inferior to our space home. The area of the entire surface of the planet slightly exceeds the area of the earth's continents combined, without taking into account the expanses of the oceans. The density here is also lower - it is only 3.93 kg / m 3.

The search for life

Despite the obvious difference between Mars and Earth, for a long time he was considered a real candidate for the title of a habitable planet. Before the beginning of the space age, scientists who observed the reddish surface of this cosmic body through a telescope periodically found signs of life, which soon, however, found a more prosaic explanation.

Over time, the conditions under which even the simplest organisms could appear outside the Earth were clearly defined. These include certain temperature parameters and the presence of water. Many explorations of the Red Planet have been aimed at discovering whether a suitable climate has developed there, and, if possible, to find traces of life.

Temperature on Mars

The Red Planet is an inhospitable world. Considerable distance from the Sun significantly affects climatic conditions this cosmic body. The temperature on Mars in Celsius varies on average from -155º to +20º. It is much colder here than on Earth, since the Sun, located one and a half times further away, warms the surface half as weakly. These not the most favorable conditions are exacerbated by a rarefied atmosphere, which transmits radiation well, which is known to be detrimental to all living things.

Such facts reduce to a minimum the chances of finding traces of existing or once extinct organisms on Mars. However, the point in this issue has not yet been set.

Determining Factors

The temperature on Mars, like on Earth, depends on the position of the planet relative to the star. Its maximum indicator (20-33º) is observed during the day near the equator. Minimum values (up to -155º) are reached in the vicinity of South Pole. Significant temperature fluctuations are characteristic of the entire territory of the planet.

These fluctuations affect both climatic features Mars, and on his appearance. The main detail of its surface, noticeable even from the Earth, is the polar caps. As a result of significant heating in summer and cooling in winter, they undergo tangible changes: either they decrease until they almost completely disappear, then they increase again.

Is there water on Mars?

When summer comes in one of the hemispheres, the corresponding polar cap begins to decrease in size. Due to the orientation of the planet's axis, as it approaches the perihelion point, the southern half turns towards the Sun. As a result, the summer here is somewhat hotter, and the polar cap disappears almost completely. In the north, this effect is not observed.

Changes in the size of the polar caps led scientists to the idea that they are composed of not quite ordinary ice. The data collected to date allow us to assume that carbon dioxide plays a significant role in their formation, which in in large numbers contains the atmosphere of Mars. In the cold season, the temperature here reaches a point at which it usually turns into the so-called dry ice. It is he who begins to melt with the advent of summer. Water, according to scientists, is also present on the planet and makes up that part of the polar caps that remains unchanged even with an increase in temperature (heating is insufficient for its disappearance).

At the same time, the planet Mars cannot boast of having the main source of life in a liquid state. Hope for its discovery for a long time instilled areas of relief, very reminiscent of riverbeds. It is still not completely clear what could have led to their formation if there was never liquid water on the Red Planet. The atmosphere of Mars testifies in favor of the "dry" past. Its pressure is so insignificant that the boiling point of water falls at temperatures unusually low for the Earth, that is, it can exist here only in a gaseous state. Theoretically, Mars could have had a denser atmosphere in the past, but then it would have left traces of it in the form of heavy inert gases. However, they have not been found so far.

Winds and storms

The temperature on Mars, more precisely, its differences, leads to rapid movement air masses in the hemisphere where winter has come. The resulting winds reach 170 m/s. On Earth, such phenomena would be accompanied by showers, but the Red Planet does not have sufficient water reserves for this. Dust storms arise here, so massive that sometimes they cover the entire planet. The rest of the time there is almost always clear weather (water is also needed to form a significant amount of clouds) and very clear air.

Despite the relatively small size of Mars and its uninhabitability, scientists have high hopes for it. Here in the future it is planned to place bases for the extraction of minerals and the implementation of various scientific activity. It is still difficult to say how real such projects are, but the continuous development of technology testifies in favor of the fact that soon humanity will be able to embody the most daring ideas.

Now Mars is dry and cold climate(left), but in the early stages of the planet's evolution, there was most likely liquid water and a dense atmosphere (right).

Studying

Observation history

Current Observations

Weather

Temperature

The average temperature on Mars is much lower than on Earth: −63°C. Since the atmosphere of Mars is very rarefied, it does not smooth out daily fluctuations in surface temperature. Under the most favorable conditions in the summer in the daytime half of the planet, the air warms up to 20 ° C (and at the equator - up to +27 ° C) - a completely acceptable temperature for the inhabitants of the Earth. Maximum temperature air, recorded by the Spirit rover, was +35 ° C. But winter at night, frost can reach even at the equator from -80 ° C to -125 ° C, and at the poles, night temperatures can drop to -143 ° C. However, diurnal temperature fluctuations are not as significant as on the atmosphereless Moon and Mercury. On Mars, there are temperature oases, in the areas of the "lake" Phoenix (plateau of the Sun) and Noah's land temperature difference is from -53°С to +22°С in summer and from -103°С to -43°С in winter. Thus, Mars is very cold world, the climate there is much harsher than in Antarctica.

*Climate of Mars, 4.5ºS, 137.4ºE (from 2012 - to today [ When?])*
Index	Jan.	Feb.	March	Apr.	May	June	July	Aug.	Sen.	Oct.	Nov.	Dec.	Year
Absolute maximum, °C	6	6	1	0	7	23	30	19	7	7	8	8	30
Average maximum, °C	−7	−18	−23	−20	−4	0	2	1	1	4	−1	−3	−5,7
Average minimum, °C	−82	−86	−88	−87	−85	−78	−76	−69	−68	−73	−73	−77	−78,5
Absolute minimum, °C	−95	−127	−114	−97	−98	−125	−84	−80	−78	−79	−83	−110	−127
Source: Centro de Astrobiología, Mars Science Laboratory Weather Twitter

Atmosphere pressure

The atmosphere of Mars is more rarefied than the Earth's air shell, and consists of more than 95% carbon dioxide, while the content of oxygen and water is a fraction of a percent. The average pressure of the atmosphere at the surface is on average 0.6 kPa or 6 mbar, which is 160 less than the earth's or equal to the earth's at an altitude of almost 35 km from the Earth's surface). Atmosphere pressure undergoes strong daily and seasonal changes.

Cloud cover and precipitation

Water vapor in the Martian atmosphere is no more than a thousandth of a percent, however, according to the results of recent (2013) studies, this is still more than previously thought, and more than in the upper layers of the Earth's atmosphere, and at low pressure and temperature, it is in a state close to saturation, so it often gathers in clouds. As a rule, water clouds form at altitudes of 10-30 km above the surface. They are concentrated mainly on the equator and are observed almost throughout the year. Clouds seen on high levels atmosphere (more than 20 km) are formed as a result of CO 2 condensation. The same process is responsible for the formation of low (at an altitude of less than 10 km) clouds in the polar regions in winter, when the atmospheric temperature drops below the freezing point of CO 2 (-126 °С); in summer, similar thin formations are formed from ice H 2 O

Formations of a condensation nature are also represented by fogs (or haze). They often stand above lowlands - canyons, valleys - and at the bottom of craters during the cold time of the day.

Blizzards can occur in the Martian atmosphere. In 2008, the Phoenix rover observed virgu in the polar regions - precipitation under the clouds, evaporating before reaching the surface of the planet. According to initial estimates, the rate of precipitation in the virga was very low. However, recent (2017) simulations of Martian atmospheric phenomena showed that at mid-latitudes, where there is a regular change of day and night, after sunset, the clouds cool sharply, and this can lead to snowstorms, during which the speed of particles can actually reach 10 m/s. Scientists assume that strong winds combined with low cloud cover (usually Martian clouds form at an altitude of 10-20 km) can cause snow to fall on the surface of Mars. This phenomenon is similar to terrestrial microbursts - squalls of downwind wind at speeds up to 35 m/s, often associated with thunderstorms.

Snow has indeed been observed more than once. So, in the winter of 1979, a thin layer of snow fell in the Viking-2 landing area, which lay for several months.

Dust storms and tornadoes

A characteristic feature of the atmosphere of Mars is the constant presence of dust, the particles of which have a size of the order of 1.5 mm and consist mainly of iron oxide. Low gravity allows even rarefied air flows to raise huge clouds of dust to a height of up to 50 km. And the winds, which are one of the manifestations of the temperature difference, often blow over the surface of the planet (especially in late spring - early summer in the southern hemisphere, when the temperature difference between the hemispheres is especially sharp), and their speed reaches 100 m/s. In this way, extensive dust storms are formed, which have long been observed in the form of individual yellow clouds, and sometimes in the form of a continuous yellow veil covering the entire planet. Most often, dust storms occur near the polar caps, their duration can reach 50-100 days. Weak yellow haze in the atmosphere, as a rule, is observed after large dust storms and is easily detected by photometric and polarimetric methods.

dust storms, which were well observed in the images taken from the orbiters, turned out to be hardly noticeable when shooting from the landers. The passage of dust storms in the landing sites of these space stations fixed only on drastic change temperature, pressure, and a very slight darkening of the general sky background. The layer of dust that settled after the storm in the vicinity of the Viking landing sites amounted to only a few micrometers. All this indicates a rather low bearing capacity of the Martian atmosphere.

From September 1971 to January 1972, a global dust storm took place on Mars, which even prevented photographing the surface from the Mariner 9 probe. The mass of dust in the atmospheric column (with an optical thickness of 0.1 to 10) estimated during this period ranged from 7.8⋅10 -5 to 1.66⋅10 -3 g/cm 2 . Thus, the total weight of dust particles in the Martian atmosphere during the period of global dust storms can reach up to 10 8 - 10 9 t, which is commensurate with total dust in earth's atmosphere.

The question of water availability

For a stable existence pure water liquid state temperature And the partial pressure of water vapor in the atmosphere should be above the triple point on the phase diagram, while now they are far from the corresponding values. Indeed, studies conducted by the Mariner 4 spacecraft in 1965 showed that there is currently no liquid water on Mars, but data from NASA's Spirit and Opportunity rovers indicate the presence of water in the past. On July 31, 2008, water in the state of ice was discovered on Mars at the landing site spacecraft NASA Phoenix. The device found ice deposits directly in the ground. There are several facts in support of the claim of the presence of water on the surface of the planet in the past. First, minerals have been found that could only form as a result of prolonged exposure to water. Secondly, very old craters are practically wiped off the face of Mars. The modern atmosphere could not cause such destruction. The study of the rate of formation and erosion of craters made it possible to establish that wind and water destroyed them most of all about 3.5 billion years ago. Many gullies have approximately the same age.

NASA announced on September 28, 2015 that Mars currently has seasonal liquid salt water flows. These structures manifest themselves in warm time years and disappear - in the cold. Planetologists came to their conclusions by analyzing high-quality images obtained by the High Resolution Imaging Science Experiment (HiRISE) scientific instrument of the Mars Reconnaissance Orbiter (MRO) Martian orbiter.

On July 25, 2018, a report was released on a discovery based on research by the MARSIS radar. The work showed the presence of a subglacial lake on Mars, located at a depth of 1.5 km under the ice of the South polar cap (at Planum Australe), about 20 km wide. This became the first known permanent body of water on Mars.

Seasons

Like on Earth, on Mars there is a change of seasons due to the tilt of the axis of rotation to the plane of the orbit, so in winter the polar cap grows in the northern hemisphere, and almost disappears in the southern, and after six months the hemispheres change places. At the same time, due to the rather large eccentricity of the planet's orbit at perihelion ( winter solstice in the northern hemisphere), it receives up to 40% more solar radiation than in aphelion, and in the northern hemisphere, winters are short and relatively moderate, and summers are long, but cool, while in the southern hemisphere, on the contrary, summers are short and relatively warm, and winters are long and cold . In this regard, the southern cap in winter grows up to half the pole-equator distance, and the northern cap only up to a third. When summer comes at one of the poles, carbon dioxide from the corresponding polar cap evaporates and enters the atmosphere; the winds carry it to the opposite cap, where it freezes again. Thus, the cycle of carbon dioxide occurs, which, along with different sizes The polar caps cause the atmospheric pressure of Mars to change as it revolves around the Sun. Due to the fact that in winter up to 20-30% of the entire atmosphere freezes in the polar cap, the pressure in the corresponding area drops accordingly.

Changes over time

As on Earth, the climate of Mars underwent long-term changes and in the early stages of the planet's evolution was very different from the current one. The difference is that leading role in cyclic changes in the Earth's climate play a change in the eccentricity of the orbit and the precession of the axis of rotation, while the tilt of the axis of rotation remains approximately constant due to the stabilizing effect of the Moon, while Mars, without such big satellite, can undergo significant changes in the inclination of its axis of rotation. Calculations have shown that the inclination of the axis of rotation of Mars, which is now 25 ° - about the same value as that of the Earth - was 45 ° in the recent past, and on a scale of millions of years could vary from 10 ° to 50 °.

Mars is farther from the Sun than Earth, so as you might expect, temperatures on Mars are colder. For the most part, the planet is very cold. The only exception is summer days at the equator. Even at the equator, temperatures on the planet Mars drop below freezing at night. On summer days, during the day it can be around 20 degrees Celsius, but at night it drops to -90 C.

Orbit

Mars has a highly elliptical orbit, so the temperature changes quite a bit as the planet orbits the sun. Since it has an axial tilt similar to Earth's (25.19 on Mars and 26.27 on Earth), the planet has seasons. Add to this a thin atmosphere and you can understand why the planet is unable to retain heat. The Martian atmosphere is made up of over 96% carbon dioxide. If the planet were able to hold on to an atmosphere, then carbon dioxide would cause a greenhouse effect that would heat it up.

Erosion marks from Mars Odyssey

The orbiters have transmitted images that indicate erosion caused by liquid water. This indicates that Mars was once significantly warmer and wetter. Erosion has not gone away because there is currently no liquid water or plate tectonics to change the landscape much. There is wind, but it is not strong enough to change the surface.

Importance of a warm climate

Availability warm weather and liquid water is important for several reasons. One of them is that liquid water has importance for the evolution of life. Some scientists are still of the opinion that microbial life exists deep below the surface, where it is warmer and water can exist in liquid form.

Colonization

If humans ever colonize the planet, they must have sources of water. The manned mission will take about two years, and the amount of cargo on board the ship will be limited. One solution is that water ice can be melted and then purified, but finding liquid water would be even more worthwhile.

Temperature is a minor barrier to early development man of the planet, while the presence of water is much more essential. All we have to do is find a way to get to Mars and back without having to spend two years in cramped spacecraft.


	· · · ·

atmospheric composition

The atmosphere of Mars is more rarefied than the air shell of the Earth, and 95% consists of carbon dioxide, about 4% is nitrogen and argon. Oxygen and water vapor in the Martian atmosphere is less than 1%. The average atmospheric pressure at the surface is 160 times less than at the Earth's surface.

The mass of the atmosphere varies greatly throughout the year due to condensation in winter time and evaporation in the summer, large volumes of carbon dioxide at the poles, in the polar caps.

Cloud cover and precipitation

There is very little water vapor in the Martian atmosphere, but at low pressure and temperature, it is in a state close to saturation, and often gathers into clouds. Martian clouds are rather inexpressive compared to those on Earth.

Temperature

There are also temperature oases on Mars, in the areas of the "lake" Phoenix (Sun Plateau) and the land of Noah, the temperature difference is from -53 ° C to + 22 ° C in summer and from -103 ° C to -43 ° C in winter. Thus, Mars is a very cold world, but the climate there is not much harsher than in Antarctica. When the first photographs of the surface of Mars taken by the Viking were transmitted to Earth, scientists were very surprised to see that the Martian sky was not black, as expected, but pink. It turned out that the dust hanging in the air absorbs 40% of the incoming sunlight, creating a color effect.

Dust storms and tornadoes

Winds are one of the manifestations of temperature difference. Over the surface of the planet often blow strong winds, the speed of which reaches 100 m/s. Low gravity allows even rarefied air currents to raise huge clouds of dust. Sometimes quite vast areas on Mars are covered by grandiose dust storms. Most often they occur near the polar caps. A global dust storm on Mars prevented photographing the surface from the Mariner 9 probe. It raged from September to January 1972, raising about a billion tons of dust into the atmosphere at an altitude of more than 10 km. Dust storms most often occur during periods of great opposition, when summer in the southern hemisphere coincides with the passage of Mars through perihelion.

Dust devils are another example of temperature-related processes on Mars. Such tornadoes are very frequent manifestations on Mars. They raise dust into the atmosphere and arise due to temperature differences. Reason: during the day, the surface of Mars heats up enough (sometimes to positive temperatures), but at a height of up to 2 meters from the surface, the atmosphere remains just as cold. Such a drop causes instability, raising dust into the air - as a result, dust devils are formed.

Seasons

At the moment it is known that of all the planets of the solar system, Mars is the most similar to the Earth. The axis of rotation of Mars is inclined to its orbital plane by approximately 23.9 °, which is comparable to the tilt of the earth's axis, which is 23.4 °, and the Martian day practically coincides with the earth's - which is why, like on Earth, the seasons change. Seasonal changes are most pronounced in the polar regions. In winter, the polar caps occupy a significant area. The boundary of the northern polar cap can move away from the pole by a third of the distance to the equator, and the boundary of the southern cap overcomes half this distance. This difference is caused by the fact that in the northern hemisphere winter occurs when Mars passes through the perihelion of its orbit, and in the southern hemisphere when it passes through aphelion. Because of this, winters in the southern hemisphere are colder than in the northern. And the duration of each of the four Martian seasons varies depending on its distance from the Sun. Therefore, in the Martian northern hemisphere, winters are short and relatively "moderate", and summers are long, but cool. In the south, on the contrary, summers are short and relatively warm, and winters are long and cold.

With the onset of spring, the polar cap begins to “shrink”, leaving behind gradually disappearing islands of ice. At the same time, a so-called wave of darkening propagates from the poles to the equator. Modern theories explain it by the fact that spring winds carry large masses of soil along the meridians with different reflective properties.

Apparently, none of the caps disappear completely. Before the start of exploration of Mars with the help of interplanetary probes, it was assumed that its polar regions were covered with frozen water. More accurate modern ground and space measurements were found in the composition martian ice also frozen carbon dioxide. In summer, it evaporates and enters the atmosphere. The winds carry it to the opposite polar cap, where it freezes again. This cycle of carbon dioxide and the different sizes of the polar caps explain the variability in the pressure of the Martian atmosphere.

The relief of the Martian surface is complex and has many details. Dried channels and canyons on the surface of Mars gave rise to assumptions about the existence of an advanced civilization on Mars - for more details, see the article Life on Mars.

A typical Martian landscape resembles a terrestrial desert, and the surface of Mars has a reddish tint due to the increased content of iron oxides in the Martian sand.

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