Temperature on Mars. The planets of the solar system. Temperature on Mars - Cold Mystery Night Temperature on Mars

The planet Mars, like another close neighbor of the Earth, Venus, has been subjected to the most intense study of astronomers since antiquity. Visible even to the naked eye, it has been shrouded in mystery, legends and speculation since ancient times. And today we do not know everything about the Red Planet, however, many information obtained over the centuries of observation and study dispelled some myths, helped a person understand many of the processes taking place on this cosmic object. The temperature on Mars, the composition of its atmosphere, features of movement in orbit after the improvement of technical research methods and the beginning space age managed to move from the category of assumptions to the rank of indisputable facts. Nevertheless, much of the data on 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 ranks fourth. Beyond the orbit of the Red Planet lies the Main Asteroid Belt and Jupiter's "dominion". 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 its aphelion is at 249.2 million km. And the day here lasts 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, it is only ahead of Mercury in size. The diameter of the Red Planet is 6,786 kilometers, which is about half that of the Earth. However, the mass of Mars is inferior to our space house 10 times. The area of \u200b\u200bthe entire surface of the planet slightly exceeds the area of \u200b\u200bthe earth's continents, taken together, excluding the vastness of the World Ocean. The density is also lower here - it is only 3.93 kg / m 3.

The search for life

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

Over time, conditions were clearly defined under which at least the simplest organisms could appear outside the Earth. These include certain temperature parameters and the presence of water. Much research on the Red Planet has aimed to find out if a suitable climate has developed there, and, if possible, find traces of life.

Temperature on Mars

The Red Planet is an inhospitable world. The considerable distance from the Sun noticeably affects climatic conditions of this cosmic body. Temperatures on Mars in Celsius range on average from -155º to + 20º. It is much colder here than on Earth, since one and a half times farther the Sun warms the surface half as weakly. These unfavorable conditions are aggravated by the rarefied atmosphere, which allows radiation to pass through well, as is known, destructive 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 put.

Determining factors

The temperature on Mars, like on Earth, depends on the position of the planet relative to the star. Its maximum value (20-33º) is observed during the day in the equator area. The minimum values \u200b\u200b(up to -155º) are reached near the South Pole. The entire territory of the planet is characterized by significant temperature fluctuations.

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

Is there water on Mars?

When summer begins 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 to 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 have prompted scientists to think that they are not quite regular ice... The data collected to date allow us to make the assumption that carbon dioxide, which contains a large amount of the atmosphere of Mars, plays a significant role in their formation. 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 arrival 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. For a long time, the hope for its discovery was inspired by areas of relief, very reminiscent of river beds. It is still not fully understood 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 on temperatures that are unusually low for the Earth, that is, it can exist here only in a gaseous state. In theory, 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, or rather, its fluctuations, leads to rapid movement air masses in the hemisphere where winter has come. The winds arising in this case 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 occur here, so large-scale that they sometimes 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 transparent air.

Despite the relatively small size of Mars and its unsuitability for life, scientists pin great hopes on it. Here, in the future, it is planned to place bases for mining and carrying out various scientific activities... It is still difficult to say how real such projects are, but the continuous development of technology testifies to the fact that soon humanity will be able to embody the most daring ideas.

The climate on Mars, although not favorable for life, is still closest to that of the Earth. Presumably in the past climate of Mars could be warmer and more humid, and on the surface there was liquid water and it even rained.

Mars is the most likely target of the first manned expedition to another planet.

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Atmospheric composition

The atmosphere of Mars is more rarefied than the Earth's air envelope, and 95.9% consists of carbon dioxide, about 1.9% is nitrogen and 2% argon. The oxygen content is 0.14%. 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.

Cloudiness 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 collects in clouds. Martian clouds are rather inexpressive compared to terrestrial ones.

Research 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, ice water was discovered on Mars at the landing site of NASA's Phoenix spacecraft. The device found ice deposits directly in the ground.

There are several facts to support the assertion of the presence of water on the planet's surface in the past. First, minerals have been found that could have formed only as a result of prolonged exposure to water. Secondly, very old craters are practically erased from the face of Mars. The modern atmosphere could not have caused 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 there are currently seasonal streams of liquid salt water on Mars. These formations manifest themselves in the warm season and disappear in the cold. Planetary scientists 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).

Temperature

The average temperature on Mars is much lower than on Earth - about -40 ° C. Under the most favorable conditions in summer, in the daytime half of the planet, the atmosphere warms up to 20 ° C - a perfectly acceptable temperature for the inhabitants of the Earth. But on a winter night, frost can reach −125 ° C. In winter temperatures, even carbon dioxide freezes into dry ice. Such sharp temperature changes are caused by the fact that the rarefied atmosphere of Mars is not able to retain heat for a long time. As a result of numerous temperature measurements in different points the surface of Mars, it turns out that during the day at the equator the temperature can reach + 27 ° С, but by morning it drops to -50 ° С.

There are temperature oases on Mars, in the regions of the "lake" Phoenix (the plateau of the Sun) and the land of Noah, the temperature difference ranges from −53 ° С to + 22 ° С in summer and from −103 ° С to −43 ° С in winter. Thus, Mars is very cold worldhowever, the climate is not much harsher than in Antarctica.

Mars - This is a harsh, cold world, the conditions on 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 also receives a quarter less solar energy than the Earth.

However, the 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, composed of 95% carbon dioxide, and unable to retain enough heat.

Why is the 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, during winter periods the temperature drops in certain 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, in Yakutia, I saw exactly the same landscapes

Temperature on Mars day and night

So, Mars is a lifeless and cold planet, because of the thin atmosphere, completely devoid of a chance to ever "warm up". However, what temperature is usually observed in Martian conditions?

Average temperature on Mars is something like minus 60 degrees Celsius. So that you understand how cold it is, here is food for thought: on Earth average temperature is +14.8 degrees, so yes, Mars is very, very "cool". In winter, in the region of the poles, the temperature 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 just extreme!

As the temperature drops, particles of carbon dioxide in the atmosphere of Mars freeze and fall out in the form of frost, covering the planet's surface and rocks like snow. The Martian "snow" has little resemblance to the earthly, because its snowflakes do not exceed the size of erythrocyte 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 white fog until it evaporates completely.

The ice caps of Mars are visible even from the ground with a good telescope

Seasons (seasons) on Mars

Like our planet, the axis of Mars is slightly tilted 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 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 for seven on Mars earthly months. Summer and fall about six months, but the Martian winter - the shortest time of the year and only lasts four months.

During the Martian summer, the planet's polar ice cap, composed mostly of carbon dioxide, shrinks significantly 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.

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

The study

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 highly rarefied, it does not smooth out daily fluctuations in surface temperature poorly. Under the most favorable conditions in summer, in the daytime half of the planet, the air warms up to 20 ° C (and at the equator - up to +27 ° C) - a perfectly 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 the night temperature can drop to -143 ° C. However, daily temperature fluctuations are not as significant as on the atmosphereless Moon and Mercury. There are temperature oases on Mars, in the regions of the Phoenix "lake" (the Sun's plateau) and the land of noah the temperature difference is from -53 ° С to + 22 ° С in summer and from -103 ° С to -43 ° С in winter. Thus, Mars is a very cold world, the climate there is much more severe than in Antarctica.

Atmosphere pressure

The atmosphere of Mars is more rarefied than the Earth's air shell, and more than 95% consists of carbon dioxide, and the content of oxygen and water is fractions of a percent. The average atmospheric pressure 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 diurnal and seasonal changes.

Cloudiness and precipitation

Water vapor in the Martian atmosphere is not more than a thousandth of a percent, however, according to the results of recent (2013) studies, this is still more than previously assumed, and more than in the upper layers of the Earth's atmosphere, and at low pressure and temperature it is in a condition close to saturation, therefore it often gathers in clouds. Typically, water clouds form 10-30 km above the surface. They are concentrated mainly at the equator and are observed almost throughout the year. The clouds observed at high levels of the atmosphere (over 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 ° C); in summer, similar thin formations are formed from ice Н 2 О

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

Blizzards can occur in the atmosphere of Mars. Mars rover "Phoenix" in 2008 observed in the circumpolar regions virgu - precipitation under the clouds, evaporating before reaching the surface of the planet. According to initial estimates, the rate of falling precipitation in the virga was very slow. However, recent (2017) simulations of the 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 blizzards, during which the speed of particles can actually reach 10 m / s. Scientists admit that strong winds combined with low clouds (usually Martian clouds form at an altitude of 10-20 km) can lead to the fact that snow will fall on the surface of Mars. This phenomenon is similar to terrestrial microbursts - squalls from a downwind with a speed of up to 35 m / s, often associated with thunderstorms.

Snow has indeed been observed many times. For example, in the winter of 1979, a thin layer of snow fell in the Viking-2 landing area, which lasted for several months.

Dust storms and tornadoes

A characteristic feature of the Martian atmosphere is the constant presence of dust, the particles of which are about 1.5 mm in size and consist mainly of iron oxide. Low gravity allows even rarefied air currents to lift huge dust clouds up to 50 km. And the winds, which are one of the manifestations of temperature differences, often blow over the planet's surface (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. Thus, 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. A faint yellow haze in the atmosphere is usually observed after large dust storms and is easily detected by photometric and polarimetric methods.

Dust storms, well observed on images taken from orbiters, turned out to be hardly noticeable when filmed from landing vehicles. The passage of dust storms at the landing sites of these space stations was recorded only by a sharp change in temperature, pressure and a very weak darkening of the general background of the sky. The dust layer that settled after the storm in the vicinity of the Viking landing sites was only a few micrometers. All this indicates a rather low bearing capacity martian atmosphere.

From September 1971 to January 1972, a global dust storm occurred on Mars, which even prevented photographing of 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, total weight dust particles in the atmosphere of Mars during the period of global dust storms can reach 10 8 - 10 9 tons, which is comparable with the total amount of dust in earthly atmosphere.

The question of water availability

For the stable existence of pure water in a liquid state, the 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, research 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, ice water was discovered on Mars at the landing site of NASA's Phoenix spacecraft. The device found ice deposits directly in the ground. There are several facts to support the assertion of the presence of water on the planet's surface in the past. First, minerals have been found that could have formed only as a result of prolonged exposure to water. Secondly, very old craters are practically erased from the face of Mars. The modern atmosphere could not have caused 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 there are currently seasonal streams of liquid salt water on Mars. These formations manifest themselves in the warm season and disappear in the cold. Planetary scientists 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).

On July 25, 2018, a report on the discovery based on research by the MARSIS radar was released. 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

As on Earth, on Mars there is a change of seasons due to the inclination of the axis of rotation to the plane of the orbit, so in winter in the northern hemisphere the polar cap grows, and in the southern one it almost disappears, 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 winter is short and relatively moderate, and summer is long, but cool, in in the south, on the contrary, the summer is short and relatively warm, and the winter is long and cold. In this regard, the southern cap in winter grows up to half the pole-equator distance, and the northern one 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 the different sizes of the polar caps, causes a change in the pressure of the atmosphere of Mars 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 region falls accordingly.

Changes over time

As on Earth, the climate of Mars has undergone long-term changes and in the early stages of the planet's evolution was very different from the current one. The difference is that the main role in the cyclic changes in the Earth's climate is played by the change in the eccentricity of the orbit and the precession of the rotation axis, while the inclination of the rotation axis remains approximately constant due to the stabilizing effect of the Moon, while Mars, not having such a large satellite, can undergo significant changes in inclination the axis of its rotation. Calculations have shown that the tilt of the Mars axis of rotation, which is now 25 ° - about the same value as that of the Earth - in the recent past was equal to 45 °, and on a scale of millions of years could fluctuate from 10 ° to 50 °.

The god of war Mars in the ancient Roman pantheon was considered the father of the Roman people, the guardian of fields and domestic animals, then the patron saint of equestrian competitions. The fourth planet from the Sun is named after him. Probably, the blood-red appearance of the planet evoked associations with war and death among the first observers. They even got the corresponding names - Phobos ("fear") and Deimos ("horror").

Red riddle

Each planet has its own mysteries, but none of them intrigued earthlings as much as Mars. The unusual red appearance of the planet remained inexplicable for a long time, it was also interesting what the temperature is on Mars, and whether its color depends on it. Today every schoolchild knows that the abundant content of iron minerals in the Martian soil gives it such a color. And in the past there were only questions to which the most inquisitive minds of earthlings were looking for answers.

Cold planet

By its age, this planet is the same as the Earth and other neighbors in the solar system. Scientists believe that her birth took place 4.6 billion years ago. And although not everything has been clarified in the history of the planet's development, much has already been established, including the temperature on Mars.

More recently, large ice deposits have been discovered at the poles in both hemispheres. This is evidence that liquid water once existed on the planet. And the temperature of Mars may have been completely different. Many scientists assume that if there is ice on the surface, then the water should be preserved in the rocks. And the presence of water is a confirmation that there was once life here.

It has been established that the planet's atmosphere has a density 100 times less than that of the Earth. But despite this, clouds and wind are formed in the layers of the Martian atmosphere. Huge dust storms sometimes rage over the surface.

What temperature on Mars is already known, and thanks to the data obtained, we can conclude that it is much colder on the red neighbor than on Earth. In the region of the poles, in winter, it was recorded at -125 degrees Celsius, and the highest in summer reaches +20 degrees in the equator.

How different from Earth

There are many differences between the planets, some of them are quite significant. Mars is much smaller in size than Earth, twice. And the planet is located much farther from the Sun: the distance to the star is almost 1.5 times farther than that of our planet.

Since the mass of the planet is relatively small, then it is almost three times less than on Earth. On Mars, as well as on our planet, there are different times years, but their duration is almost twice as long.

Unlike Earth, Mars, the average air temperature of which is -30 ...- 40 ° C, has a very rarefied atmosphere. Its composition is dominated by carbon dioxide, which implies the absence. Therefore, during the day, the temperature on Mars near the surface changes significantly. For example, at noon it can be -18 ° C, and in the evening - already -63 ° C. At night, the temperature at the equator was recorded and 100 degrees below zero.