Mars rotation speed. Life on Mars

Mars is the fourth planet from the Sun and the last of the terrestrial planets. Like the rest of the planets solar system(not counting the Earth) is named after the mythological figure - the Roman god of war. In addition to its official name, Mars is sometimes referred to as the Red Planet, referring to the brown-red color of its surface. With all this, Mars is the second smallest planet in the solar system after.

For most of the nineteenth century, life was thought to exist on Mars. The reason for this belief lies partly in error and partly in human imagination. In 1877, astronomer Giovanni Schiaparelli was able to observe what he thought were straight lines on the surface of Mars. Like other astronomers, when he noticed these stripes, he suggested that such directness is associated with the existence on the planet intelligent life. The version popular at that time about the nature of these lines was the assumption that they were irrigation canals. However, with the development of more powerful telescopes in the early twentieth century, astronomers were able to see the Martian surface more clearly and determine that these straight lines were just an optical illusion. As a result, all earlier assumptions about life on Mars were left without evidence.

Much of the science fiction written during the twentieth century was a direct consequence of the belief that life existed on Mars. From little green men to tall, laser-wielding invaders, Martians have been the focus of many television and radio programs, comics, films, and novels.

Despite the fact that the discovery of Martian life in the eighteenth century turned out to be false as a result, Mars remained for the scientific community the most life-friendly (other than Earth) planet in the solar system. Subsequent planetary missions were no doubt dedicated to the search for any form of life on Mars. So a mission called Viking, carried out in the 1970s, conducted experiments on Martian soil in the hope of finding microorganisms in it. At the time, it was believed that the formation of compounds during experiments could be the result of biological agents, but later it was found that the compounds chemical elements can be created without biological processes.

However, even these data did not deprive scientists of hope. Finding no signs of life on the surface of Mars, they suggested that all the necessary conditions could exist below the surface of the planet. This version is still relevant today. At the very least, such planetary missions of the present as ExoMars and Mars Science involve checking all options the existence of life on Mars in the past or present, on the surface and below it.

Atmosphere of Mars

The composition of the atmosphere of Mars is very similar to the atmosphere, one of the least hospitable atmospheres in the entire solar system. The main component in both environments is carbon dioxide (95% for Mars, 97% for Venus), but there is a big difference - the greenhouse effect on Mars is absent, so the temperature on the planet does not exceed 20 ° C, in contrast to 480 ° C on the surface of Venus. Such a huge difference is due to the different density of the atmospheres of these planets. At a comparable density, the atmosphere of Venus is extremely thick, while Mars has a rather thin atmospheric layer. Simply put, if the thickness of the atmosphere of Mars were more significant, then it would resemble Venus.

In addition, Mars has a very rarefied atmosphere - atmospheric pressure is only about 1% of the pressure on. This is equivalent to a pressure of 35 kilometers above the Earth's surface.

One of the earliest directions in the study of the Martian atmosphere is its influence on the presence of water on the surface. Despite the fact that the polar caps contain water in a solid state, and the air contains water vapor formed as a result of frost and low pressure, today all studies indicate that the "weak" atmosphere of Mars does not contribute to the existence of water in a liquid state on the surface of the planet.

However, relying on the latest data from Martian missions, scientists are confident that liquid water exists on Mars and is one meter below the surface of the planet.

Water on Mars: speculation / wikipedia.org

However, despite the thin atmospheric layer, Mars has quite acceptable by earthly standards. weather conditions. The most extreme forms of this weather are winds, dust storms, frosts and fogs. As a result of such weather activity, significant traces of erosion have been observed in some areas of the Red Planet.

Another interesting point about the Martian atmosphere is that, according to several modern scientific research, in the distant past, it was dense enough for the existence of oceans on the surface of the planet from water in a liquid state. However, according to the same studies, the atmosphere of Mars has been dramatically changed. The leading version of such a change to this moment is a hypothesis about the collision of the planet with another sufficiently voluminous cosmic body, which led to the loss of Mars of most of its atmosphere.

The surface of Mars has two significant features, which, by an interesting coincidence, are associated with differences in the hemispheres of the planet. The fact is that the northern hemisphere has a fairly smooth relief and only a few craters, while the southern hemisphere is literally dotted with hills and craters of various sizes. In addition to topographical differences, which indicate the difference in the relief of the hemispheres, there are also geological ones - studies indicate that areas in the northern hemisphere are much more active than in the southern.

On the surface of Mars is the largest volcano known to date - Olympus Mons (Mount Olympus) and the largest known canyon - Mariner (Mariner Valley). Nothing more grandiose has yet been found in the solar system. The height of Mount Olympus is 25 kilometers (that's three times higher than Everest, the highest mountain on Earth), and the diameter of the base is 600 kilometers. The Mariner Valley is 4,000 kilometers long, 200 kilometers wide and almost 7 kilometers deep.

To date, the most significant discovery regarding the Martian surface has been the discovery of channels. A feature of these channels is that, according to NASA experts, they were created running water, and thus provide the most reliable evidence for the theory that, in the distant past, the surface of Mars greatly resembled that of Earth.

The most famous peridolia associated with the surface of the Red Planet is the so-called "Face on Mars". The relief really looked very much like a human face when the first image of a certain area was taken by the Viking I spacecraft in 1976. Many people at the time considered this image to be real proof that intelligent life existed on Mars. Subsequent shots showed that this is just a game of lighting and human fantasy.

Like other terrestrial planets, three layers are distinguished in the interior of Mars: the crust, mantle, and core.
Although exact measurements have not yet been made, scientists have made certain predictions about the thickness of the Martian crust based on data on the depth of the Mariner Valley. The deep, vast system of the valley, located in the southern hemisphere, could not exist if the crust of Mars was not much thicker than the earth. Preliminary estimates indicate that the thickness of the Martian crust in the northern hemisphere is about 35 kilometers and about 80 kilometers in the southern.

Quite a lot of research has been devoted to the core of Mars, in particular, to find out whether it is solid or liquid. Some theories pointed to the lack of a sufficiently powerful magnetic field as a sign of a hard core. However, in the last decade, the hypothesis that the core of Mars is liquid, at least in part, is gaining more and more popularity. This was indicated by the discovery of magnetized rocks on the planet's surface, which may be a sign that Mars has or had a liquid core.

Orbit and rotation

Mars' orbit is notable for three reasons. First, its eccentricity is the second largest of all the planets, only Mercury is smaller. In this elliptical orbit, Mars' perihelion is 2.07 x 108 kilometers, much further than its aphelion, 2.49 x 108 kilometers.

Secondly, scientific evidence suggests that such a high degree of eccentricity was far from always present, and may have been less than Earth's at some point in the history of Mars. The reason for this change, scientists call the gravitational forces of neighboring planets that affect Mars.

Thirdly, of all the terrestrial planets, Mars is the only one on which the year lasts longer than on Earth. Naturally, this is related to its orbital distance from the Sun. One Martian year is equal to almost 686 Earth days. A Martian day lasts approximately 24 hours and 40 minutes, which is the time it takes for the planet to complete one complete revolution on its axis.

Another notable similarity between the planet and Earth is its axial tilt, which is approximately 25°. This feature indicates that the seasons on the Red Planet follow each other in exactly the same way as on Earth. However, the hemispheres of Mars experience completely different temperature regimes for each season, different from those on Earth. This is again due to the much greater eccentricity of the planet's orbit.

SpaceX And ​​plans to colonize Mars

So we know that SpaceX wants to send humans to Mars in 2024, but their first Martian mission will be the launch of the Red Dragon capsule in 2018. What steps is the company going to take to achieve this goal?

• 2018 year. Launch of the Red Dragon space probe to demonstrate technology. The goal of the mission is to reach Mars and do some surveys on the landing site on a small scale. Perhaps the supply of additional information for NASA or space agencies of other states.
• 2020 Launch of the Mars Colonial Transporter MCT1 spacecraft (unmanned). The purpose of the mission is to send cargo and return samples. Large-scale demonstrations of technology for habitation, life support, energy.
• 2022 Launch of the Mars Colonial Transporter MCT2 spacecraft (unmanned). Second iteration of MCT. At this time, MCT1 will be on its way back to Earth, carrying Martian samples. MCT2 is supplying equipment for the first manned flight. The MCT2 ship will be ready for launch as soon as the crew arrives on the Red Planet in 2 years. In the event of trouble (as in the movie "The Martian"), the team will be able to use it to leave the planet.
• 2024 Third iteration of the Mars Colonial Transporter MCT3 and first manned flight. At that time, all technologies will prove their performance, MCT1 will make a trip to Mars and back, and MCT2 is ready and tested on Mars.

Mars is the fourth planet from the Sun and the last of the terrestrial planets. The distance from the Sun is about 227,940,000 kilometers.

The planet is named after Mars, the Roman god of war. He was known to the ancient Greeks as Ares. It is believed that Mars received such an association because of the blood-red color of the planet. Due to its color, the planet was also known to other ancient cultures. The first Chinese astronomers called Mars the "Star of Fire", and the ancient Egyptian priests designated it as "Her Desher", which means "red".

The landmass on Mars is very similar to that on Earth. Despite the fact that Mars occupies only 15% of the volume and 10% of the mass of the Earth, it has a land mass comparable to our planet as a result of the fact that water covers about 70% of the Earth's surface. At the same time, the surface gravity of Mars is about 37% of the gravity on Earth. This means that you can theoretically jump three times higher on Mars than on Earth.

Only 16 out of 39 missions to Mars were successful. Since the Mars 1960A mission launched in the USSR in 1960, a total of 39 descent orbiters and rovers have been sent to Mars, but only 16 of these missions have been successful. In 2016, a probe was launched as part of the Russian-European ExoMars mission, the main objectives of which will be to search for signs of life on Mars, study the surface and topography of the planet, and map potential hazards from environment for future manned missions to Mars.

Debris from Mars has been found on Earth. It is believed that traces of some of the Martian atmosphere have been found in meteorites that have bounced off the planet. After they left Mars, these meteorites for a long time, for millions of years, flew around the solar system among other objects and space debris, but were captured by the gravity of our planet, fell into its atmosphere and collapsed to the surface. The study of these materials allowed scientists to learn a lot about Mars even before the start of space flights.

In the recent past, people were convinced that Mars was home to intelligent life. This was largely influenced by the discovery of straight lines and ditches on the surface of the Red Planet by the Italian astronomer Giovanni Schiaparelli. He believed that such straight lines cannot be created by nature and are the result of intelligent activity. However, it was later proven that this was nothing more than an optical illusion.

The highest planetary mountain known in the solar system is on Mars. It is called Olympus Mons (Mount Olympus) and rises 21 kilometers in height. It is believed that this is a volcano that was formed billions of years ago. Scientists have found enough evidence that the age of the volcanic lava of the object is quite small, which may be evidence that Mount Olympus may still be active. However, there is a mountain in the solar system that Olympus is inferior in height to - this is the central peak of Reyasilvia, located on the asteroid Vesta, whose height is 22 kilometers.

Dust storms occur on Mars - the most extensive in the solar system. This is due to the elliptical shape of the trajectory of the planet's orbit around the Sun. The path of the orbit is more elongated than that of many other planets, and this oval shape of the orbit results in ferocious dust storms that engulf the entire planet and can last for many months.

The Sun appears to be about half its visual Earth size when viewed from Mars. When Mars is closest to the Sun in its orbit, and its southern hemisphere is facing the Sun, the planet experiences a very short but incredibly hot summer. At the same time, a short but cold winter sets in in the northern hemisphere. When the planet is further from the Sun, and pointed towards it by the northern hemisphere, Mars experiences a long and mild summer. At the same time, a long winter sets in in the southern hemisphere.

With the exception of the Earth, scientists consider Mars the most suitable planet for life. Leading space agencies are planning a series of spaceflights over the next decade to find out if Mars has the potential for life to exist and whether it is possible to build a colony on it.

Martians and aliens from Mars have long been the main candidates for the role of extraterrestrial aliens, which has made Mars one of the most popular planets in the solar system.

Mars is the only planet in the system other than Earth that has polar ice. Solid water has been discovered under the polar caps of Mars.

Just like on Earth, Mars has seasons, but they last twice as long. This is because Mars is tilted on its axis by about 25.19 degrees, which is close to Earth's axial tilt (22.5 degrees).

Mars has no magnetic field. Some scientists believe that it existed on the planet about 4 billion years ago.

The two moons of Mars, Phobos and Deimos, were described in Gulliver's Travels by author Jonathan Swift. This was 151 years before they were discovered.

The red planet - Mars - is named after the ancient Roman god of war of the same name, similar to Ares among the Greeks. It is the fourth, in terms of distance, distant from the Sun, the planet of the solar system. It is believed that it is the blood-red color of the planet, which gives it iron oxide, and influenced its name.

Mars has always been curious not only to scientists, but also to ordinary people various professions. All because humanity had high hopes for this planet, because most people hoped that life also exists on the surface of Mars. Most science fiction novels are written about the planet Mars. Trying to penetrate the secrets and unravel its riddles, people rapidly studied the surface and structure of the planet. But so far they have not managed to get an answer to such an exciting question: “Is there life on Mars?” Mars rotates in its slightly elongated orbit around the Sun in 687 Earth days, at a speed of 24 km / s. Its radius is 1.525 astronomical units. The distance from Earth to Mars is constantly changing from a minimum of 55 million km to a maximum of 400 million km. Great confrontations are those periods of time that repeat every 16-17 years, when the distance between these two planets becomes less than 60 million km. A day on Mars is only 41 minutes longer than on Earth and is 24 hours 62 minutes. The change of day and night, as well as the seasons, also practically repeats the earthly ones. There is also climatic zones, but due to the greater distance from the Sun, they are much more severe than on our planet. Thus, the average temperature is about -50 °C. The radius of Mars is 3397 km, which is almost half the radius of the Earth - 6378.

Surface and structure of Mars

Mars, along with other terrestrial planets, consists of a crust up to 50 km thick, a mantle up to 1800 km and a core with a diameter of 2960 km.

In the center of Mars, the density reaches 8.5 g/m3. In the course of long-term studies, it was found that the internal structure of Mars and its current surface consists mainly of basalt. It is assumed that several million, and maybe billions of years ago, there was an atmosphere on the planet Mars. Accordingly, the water was in a liquid state. This is evidenced by numerous riverbeds - meanders, which can be observed even now. characteristic geological formation on their bottom, indicate that they have been leaking for a very long period of time. Now, for this there is no necessary conditions and water is only in the layers of soil, under the very surface of Mars. This phenomenon is called permafrost (permafrost). Description of Mars and its characteristics are often found in the reports of famous explorers of the "Red Planet".

The rest of the surface of Mars and its relief, has no less unique finds. The structure of Mars is characterized by deep craters. At the same time, on this planet, there is the most high mountain throughout the solar system - Olympus - Martian dormant volcano 27.5 km high and 6000 m in diameter. Also, there is a grandiose system of Mariner canyons about 4 thousand km long and a whole area of ​​ancient volcanoes - Elysium.

Phobos and Deimos are natural, but very small, satellites of Mars. They don't have correct form, and according to one version, they are asteroids captured by the gravity of Mars. The satellites of Mars Phobos (fear) and Deimos (horror) are the heroes of ancient Greek myths in which they helped the god of war Ares (Mars) to win battles. In 1877, they were discovered by American astronomer Asaph Hall. The rotation of both satellites along their axis occurs with the same period, as well as around Mars, due to this they are always facing the planet on one side. Deimos gradually succeeds from Mars, and Phobos, on the contrary, is attracted even more. But this happens very slowly, therefore, it is unlikely that our next generations will be able to see the fall or complete decay of the satellite, or its fall to the planet.

Characteristics of Mars

Mass: 6.4 * 1023 kg (0.107 Earth masses)
Diameter at equator: 6794 km (0.53 Earth diameter)
Axis Tilt: 25°
Density: 3.93 g/cm3
Surface temperature: -50 °C
Period of revolution around the axis (day): 24 hours 39 minutes 35 seconds
Distance from the Sun (average): 1.53 AU e. = 228 million km
Orbital period around the Sun (year): 687 days
Orbital speed: 24.1 km/s
Orbital eccentricity: e = 0.09
Orbital inclination to the ecliptic: i = 1.85°
Free fall acceleration: 3.7 m/s2
Moons: Phobos and Deimos
Atmosphere: 95% carbon dioxide, 2.7% nitrogen, 1.6% argon, 0.2% oxygen

Composition of the atmosphere 95.72% ar. gas
0.01% Nitric oxide

Mars- the fourth largest planet from the Sun and the seventh largest planet in the solar system. This planet is named after Mars, the ancient Roman god of war, corresponding to the ancient Greek Ares. Mars is sometimes referred to as the "Red Planet" because of the reddish hue of the surface given to it by iron(III) oxide.

Basic information

Due to the low pressure, water cannot exist in a liquid state on the surface of Mars, but it is likely that conditions were different in the past, and therefore the presence of primitive life on the planet cannot be ruled out. On July 31, 2008, ice water was discovered on Mars by NASA's Phoenix spacecraft. Phoenix) .

Currently (February 2009) the orbital research constellation in the orbit of Mars has three functioning spacecraft: " Mars Odyssey", " Mars Express" and " Mars Reconnaissance Orbiter", and this is more than around any other planet except Earth. The surface of Mars is currently being explored by two rovers: Spirit and Opportunity. There are also several inactive landers and rovers on the surface of Mars that have completed their missions. The geological data collected by all these missions suggests that a large part of the surface of Mars was previously covered with water. Observations over the past decade have revealed weak geyser activity in some places on the surface of Mars. Observations from the NASA spacecraft "Mars Global Surveyor", some parts of the south polar cap of Mars are gradually receding.

Mars has two natural satellites, Phobos and Deimos (translated from ancient Greek - "fear" and "horror" - the names of the two sons of Ares, who accompanied him in battle), which are relatively small and have an irregular shape. They may be asteroids trapped in the gravitational field of Mars, like asteroid 5261 Eureka of the Trojan Group.

Mars can be seen from Earth with the naked eye. Its apparent stellar magnitude reaches −2.91 m (at the closest approach to the Earth), yielding in brightness only to Jupiter, Venus, the Moon and the Sun.

Orbital characteristics

The minimum distance from Mars to Earth is 55.75 million km, the maximum is about 401 million km. The average distance from Mars to the Sun is 228 million km. km (1.52 AU), the period of revolution around the Sun is 687 Earth days. The orbit of Mars has a rather noticeable eccentricity (0.0934), so the distance to the Sun varies from 206.6 to 249.2 million km. The orbital inclination of Mars is 1.85°.

The atmosphere is 95% carbon dioxide; it also contains 2.7% nitrogen, 1.6% argon, 0.13% oxygen, 0.1% water vapor, 0.07% carbon monoxide. The Martian ionosphere extends from 110 to 130 km above the surface of the planet.

According to the results of observations from the Earth and data from the Mars Express spacecraft, methane was detected in the atmosphere of Mars. Under the conditions of Mars, this gas decomposes rather quickly, so there must be permanent source its replenishment. Such a source can be either geological activity (but no active volcanoes have been found on Mars), or the vital activity of bacteria.

The climate, like on Earth, is seasonal. In the cold season, even outside the polar caps, light frost can form on the surface. The Phoenix device recorded a snowfall, however, the snowflakes evaporated before reaching the surface.

According to researchers from the Carl Sagan Center, Mars is currently undergoing a warming process. Other experts believe that it is too early to draw such conclusions.

Surface

Description of the main regions

Topographic map of Mars

Two-thirds of the surface of Mars is occupied by light areas, called continents, about a third - by dark areas, called seas. The seas are concentrated mainly in the southern hemisphere of the planet, between 10 and 40 ° latitude. There are only two large seas in the northern hemisphere - the Acidalian and the Great Syrt.

The nature of the dark areas is still a matter of controversy. They persist despite dust storms raging on Mars. This at one time served as an argument in favor of the fact that the dark areas are covered with vegetation. Now it is believed that these are just areas from which, due to their relief, dust is easily blown out. Large-scale images show that the dark areas are actually made up of groups of dark streaks and patches associated with craters, hills, and other obstructions in the path of the winds. Seasonal and long-term changes in their size and shape are apparently associated with a change in the ratio of surface areas covered with light and dark matter.

The hemispheres of Mars are quite different in the nature of the surface. In the southern hemisphere, the surface is 1-2 km above the mean level and is heavily cratered. This part of Mars resembles the lunar continents. In the north, the surface is mostly below-average, with few craters, and the main part is occupied by relatively smooth plains, probably formed by lava flooding and erosion. This difference between the hemispheres remains a matter of debate. The boundary between the hemispheres follows approximately a great circle inclined at 30° to the equator. The boundary is wide and irregular and forms a slope towards the north. Along it there are the most eroded areas of the Martian surface.

Two alternative hypotheses have been put forward to explain the asymmetry of the hemispheres. According to one of them, at an early geological stage, the lithospheric plates "came together" (perhaps by accident) into one hemisphere (like the Pangea continent on Earth) and then "frozen" in this position. Another hypothesis involves the collision of Mars with a cosmic body the size of Pluto.

A large number of craters in the southern hemisphere suggests that the surface here is ancient - 3-4 billion years. years. Several types of craters can be distinguished: large craters with a flat bottom, smaller and younger cup-shaped craters similar to the moon, craters surrounded by a rampart, and elevated craters. The last two types are unique to Mars - rimmed craters formed where liquid ejecta flowed over the surface, and elevated craters formed where a crater ejecta blanket protected the surface from wind erosion. The largest feature of impact origin is the Hellas basin (about 2100 km across).

In a region of chaotic landscape near the hemispheric boundary, the surface experienced large areas of fracture and compression, sometimes followed by erosion (due to landslides or catastrophic release of groundwater) and flooding with liquid lava. Chaotic landscapes are often found at the head of large channels cut by water. The most acceptable hypothesis for their joint formation is the sudden melting of subsurface ice.

In the northern hemisphere, in addition to vast volcanic plains, there are two areas of large volcanoes - Tarsis and Elysium. Tarsis is a vast volcanic plain 2000 km long, reaching a height of 10 km above the average level. There are three large shield volcanoes on it - Arsia, Pavonis (Peacock) and Askreus. On the edge of Tarsis is the highest mountain on Mars and in the solar system, Mount Olympus. Olympus reaches 27 km in height, and covers an area of ​​​​550 km in diameter, surrounded by cliffs, in places reaching 7 km in height. The volume of Mount Olympus is 10 times the volume of the largest volcano on Earth, Mauna Kea. Several smaller volcanoes are also located here. Elysium - a hill up to six kilometers above the average level, with three volcanoes - Hecate, Elysium and Albor.

Channels of "rivers" and other features

There is also a significant amount of water ice in the ground at the landing site of the apparatus.

Geology and internal structure

Unlike Earth, there is no movement of lithospheric plates on Mars. As a result, volcanoes can exist much longer long time and reach gigantic proportions.

Phobos (top) and Deimos (bottom)

Modern models of the internal structure of Mars suggest that Mars consists of a crust with an average thickness of 50 km (and a maximum thickness of up to 130 km), a silicate mantle 1800 km thick, and a core with a radius of 1480 km. The density in the center of the planet should reach 8.5/cm³. The core is partially liquid and consists mainly of iron with an admixture of 14-17% (by mass) of sulfur, and the content of light elements is twice as high as in the core of the Earth.

Moons of Mars

The natural satellites of Mars are Phobos and Deimos. Both were discovered by the American astronomer Asaph Hall in 1877. Phobos and Deimos are irregularly shaped and very small. According to one hypothesis, they may represent asteroids captured by the gravitational field of Mars, like 5261 Eureka from the Trojan group of asteroids.

Astronomy on Mars

This section is a translation of the English Wikipedia article

After the landings automatic devices on the surface of Mars, it became possible to conduct astronomical observations directly from the surface of the planet. Due to the astronomical position of Mars in the solar system, the characteristics of the atmosphere, the period of revolution of Mars and its satellites, the picture of the night sky of Mars (and astronomical phenomena observed from the planet) differs from the earth's and in many ways seems unusual and interesting.

Noon on Mars. Pathfinder image

Sunset on Mars. Pathfinder image

The color of the sky on Mars Earth and Moon Satellites - Phobos and Deimos

On the surface planets operate two rovers:

Planned missions

In culture

Books

• A. Bogdanov "Red Star"
• A. Kazantsev "Faetes"
• A. Shalimov "Price of immortality"
• V.Mikhailov "Special Necessity"
• V. Shitik "The Last Orbit"
• B. Lyapunov "We are on Mars"
• G.Martynov "Stargazers" trilogy
• G. Wells "War of the Worlds", the film of the same name in two adaptations
• Simmons, Dan "Hyperion", tetralogy
• Stanislav Lem "Ananke"

Films

• "Journey to Mars" USA, 1903
• "Journey to Mars" USA, 1910
• "Skyship" Denmark, 1917
• "Journey to Mars" Denmark, 1920
• "Journey to Mars" Italy, 1920
• "Ship sent to Mars" USA, 1921
• "Aelita" directed by Yakov Protazanov, USSR, 1924
• "Journey to Mars" USA, 1924
• "To Mars" USA, 1930
• "Flash Gordon: Mars Attacks the Earth" USA, 1938
• "Scrappy's Journey to Mars" USA, 1938
• "X-M Rocket" USA, 1950
• "Flight to Mars" USA, 1951
• "The sky is calling" directors A. Kozyr and M. Karyukov, USSR, 1959
• "Mars" documentary, director Pavel Klushantsev, USSR, 1968
• “First on Mars. The unsung song of Sergei Korolev, documentary, 2007
• "Martian Odyssey"

Other

• In the fictional universe of Warhammer 40,000, Mars is the capital world of the Adeptus Mechanicus organization, which supports the scientific and technical thought of the Imperium of Man.
• In the video game DOOM 3, the setting is the Red Planet.
• In the video game Red Faction 1.3, the setting is also the "Red Planet".
• In the universe of Mass Effect at the south pole of Mars, a database of long-disappeared aliens was found, the decoding of which allowed people to enter the Galaxy.

RED PLANET MARS

Mars is the first planet in the solar system after the Earth, in which people have begun to show special interest for some time, caused by the hope that developed extraterrestrial life exists there.

The planet is named Mars in honor of the ancient Roman god of war (the same as Ares in ancient Greek mythology) forits blood-red color, due to the presence of iron oxide in the soil of Mars.

Main characteristics

Mars is the fourth largest planet from the Sun and the seventh largest planet in the solar system.It can be seen from Earth with the naked eye. It is second in brightness only to Venus, the Moon and the Sun.

Mars nearly doubled smaller than Earth in size - its equatorial radius is equal to3,396.9 kilometers (53.2% of the earth). The surface area of ​​Mars is roughly equal to the land area of ​​Earth.

The average distance from Mars to the Sun is 228 million kilometers, the period of revolution around the Sun is 687 Earth days.

The minimum distance from Mars to Earth is 55.75 million kilometers, the maximum is about 401 million kilometers.

Mars is closest to Earth during opposition, when the planet is in the opposite direction from the Sun.The distances between the Earth and Mars at the moments of confrontation vary from 55 to 102 million kilometers. A great opposition is called when the distance between two planets becomes less than 60 million kilometers. The great opposition of Earth and Mars is repeated every 15-17 years (the last was in August 2003).And the usual ones - every 26 months at different points in the orbit of Mars and the Earth.

Mars has a rotation period and seasons similar to Earth's, but its climate is much colder and drier than Earth's.

The planet's rotation period is 24 hours 37 minutes 22.7 seconds.

On Mars, as on Earth, there are two poles, North and South. Mars rotates fast enough that it has a slightly flattened shape at both poles. At the same time, the polar radius of the planet is about 21 kilometers less than the equatorial one.

A Martian year consists of 668.6 Martian solar days called salts.

The mass of the planet Mars is 6.418 × 1023 kilograms (11% of the mass of the Earth).

Mars has two natural satellites, Phobos and Deimos, and three artificial satellites.

As of February 2009, there are three operational spacecraft orbiting Mars: Mars Odyssey, Mars Express and Mars Reconnaissance Orbiter, more than any other planet except Earth.

There are several inactive landers and rovers on the surface of Mars that have completed their missions.

Climate of Mars

The climate on Mars, like on Earth, is seasonal. The change of seasons on Mars occurs in much the same way as on Earth, but the climate there is colder and drier than ours. In the cold season, even outside the polar caps, light frost can form on the surface. A picture of frost was once taken by the Viking 2 aircraft..

Mars rover "Phoenix" at some point succeededto fix falling snow on Mars during"Martian winter". Snowfall on Mars was recorded using a laser, which is equipped with a rover. The rover managed to fix the snow with the help of a special laser with which it was equipped. Snow fell from a height of about 4000 meters, but it did not reach the surface of the planet, dissolving in the air.

The change of seasons on Mars is provided bytilt of its axis of rotation. In this case, the elongation of the orbit leads to large differences in the duration of the seasons. Unlike earthly ones, which have the same duration of 3 months. Mars has northern spring and summer, which fall on the part of the orbit that is farthest from the Sun. These seasons together last 371 sols, that is, noticeably more than half of the Martian year. Therefore, on Mars, northern summers are long and cool, while southern summers are short and hot.

Mars is characterized by a sharp temperature drop. Temperatures at the planet's equator range from +30°C at noon to -80°C at midnight. Near the poles, the temperature sometimes drops to −143°C, at which temperature carbon dioxide condenses. Mars is a very cold world, but the climate there is not much harsher than in Antarctica.

There is currently no liquid water on Mars. However, most likely, the white polar caps, discovered in 1704, consist of water ice mixed with solid carbon dioxide. In winter, they extend a third (the south polar cap - half) of the distance to the equator. In the spring, this ice partially melts, and a wave of darkening spreads from the poles to the equator, which was previously mistaken for Martian plants.

The appearance of Mars varies greatly depending on the time of year. First of all, changes in the polar caps are striking. They grow and shrink, creating seasonal phenomena in the atmosphere and on the surface of Mars.The polar caps consist of two components: seasonal - carbon dioxide and secular - water ice. The thickness of the caps can range from 1 meter to 3.7 kilometers.

Previously, many researchers seriously believed that there is still water in a liquid state on the surface of Mars. This opinion was based on observations of periodic changes in light and dark areas, especially in polar latitudes, which were similar to continents and seas.

Dark grooves on the surface of Mars have been explained by some observers as channels for liquid water.

Later it was proved that these furrows did not actually exist, but were just an optical illusion.

Research conducted by the Mariner 4 spacecraft in 1965 showed that there is currently no liquid water on Mars.

Due to the low pressure, water cannot exist in a liquid state on the surface of Mars. With such a small pressure that is currently acting on the planet, it boils at very low temperatures, but it is likely that conditions were different in the past, and therefore the presence of primitive life on the planet cannot be ruled out.

On July 31, 2008, water in the state of ice was discovered on Mars at the landing site of NASA's Phoenix spacecraft. The device found ice deposits directly in the ground.

Data from NASA's Spirit and Opportunity rovers also provide evidence for the presence of water in the past (minerals found that could only form as a result of prolonged exposure to water).

The glacier hundreds of meters thick covers an area of ​​thousands of square kilometers, and its further study can provide information about the history of the Martian climate.

By modern ideas, the total volume of ice enclosed in the polar cap of the northern hemisphere is approximately 1.5 million kilometers, therefore, in the melted form, this ice could not form a giant ocean, which, according to many researchers, once covered almost the entire northern hemisphere of Mars. Thus, it remains a mystery where the water that once abounded on the now arid planet has gone.

Presumablyin the past, the climate of Mars may have been warmer and wetter, and liquid water was present on the surface, and it even rained.

Magnetic field and atmosphere of Mars

Mars has a magnetic field, but it is weak and extremely unstable. In different parts of the planet, it can differ from 1.5 to 2 times. At the same time, the magnetic poles of the planet do not coincide with the physical ones. This suggests that the iron core of Mars is more or less motionless relative to its crust, that is, the mechanism responsible for the Earth's magnetic field does not work on Mars.

Modern models of the internal structure of Mars suggest that Mars consists of a crust with an average thickness of 50 kilometers (and a maximum thickness of up to 130 kilometers), a silicate mantle (mantle enriched in iron) with a thickness of 1800 kilometers and a core with a radius of 1480 kilometers.

According to calculations, the core of Mars has a mass of up to 9% of the mass of the planet. It consists of iron and its alloys, while the core is in a liquid state.

Perhaps in the distant past as a result of a collision with a large celestial body there was a stop of rotation of the nucleus, as well as the loss of the main volume of the atmosphere.It is believed that the loss of the magnetic field occurred about 4 billion years ago.

Because the magnetic field of Mars is so weak, the solar wind freely penetrates its atmosphere. Because of this, many reactions under the influence of solar radiation on Mars occur almost at its very surface.On Earth, a strong magnetic field does not transmit solar radiation, so all these reactions occur in the ionosphere and above.

The Martian ionosphere extends over the surface of the planet from 110 to 130 kilometers.

The atmosphere of Mars is 95% carbon dioxide. The atmosphere also contains 2.5-2.7% nitrogen, 1.5-2% argon, 0.13% oxygen, 0.1% water vapor, 0.07% carbon monoxide.

In addition, the atmosphere of Mars is very rarefied. The pressure at the surface of Mars is 160 times less than the Earth's at the average surface level. Due to the large elevation difference on Mars, the surface pressure varies greatly.

Unlike Earth, the mass of the Martian atmosphere varies greatly during the year due to the melting and freezing of the polar caps containing carbon dioxide.

There is evidence that the atmosphere may have been thicker in the past.

Topography of Mars

Studies have shown that two-thirds of the surface of Mars is occupied by light areas, called continents, and the remaining third is dark areas, called seas. The nature of the dark areas is still a matter of controversy.But in fact, no water has been found in the Martian seas.

The seas are concentrated mainly in the southern hemisphere of the planet. There are only two large seas in the northern hemisphere - the Acidalian and the Great Syrt.

Large-scale images show that the dark areas are actually made up of groups of dark streaks and patches associated with craters, hills, and other obstructions in the path of the winds. Seasonal and long-term changes in their size and shape are apparently associated with a change in the ratio of surface areas covered with light and dark matter.

The hemispheres of Mars are quite different in the nature of the surface. The surface of Mars has a reddish color due to large impurities of iron oxides.

Everywhere on the surface of Mars lie boulders - pieces of volcanic rocks that have broken off during marsquakes or meteorite falls.

From time to time come across craters - the remains of meteorite impacts.

In some places, the surface is covered with multi-layered rocks similar to those on Earth. sedimentary rocks remaining after the retreat of the sea.

In the southern hemisphere, the surface is 1-2 kilometers above the mean level and is densely dotted with craters. This part of Mars resembles the lunar continents.

A large number of craters in the southern hemisphere may indicate that the surface here is ancient - 3-4 billion years.

The rovers exploring the planet left their marks on the untouched surface.

In the north, the surface is mostly below average, with few craters and mostly relatively smooth plains, probably formed by lava flooding and soil erosion.

In the northern hemisphere there are two areas of large volcanoes - Tarsis and Elysium.

Tharsis is a vast volcanic plain 2000 kilometers long, reaching a height of 10 kilometers above the average level. It has three large volcanoes.

On the edge of Tarsis is the highest mountain on Mars and on the planets in the solar system - the Martian extinct volcano Olympus.

Olympus reaches 27 kilometers in height and 550 kilometers in diameter. The cliffs that surround the volcano, in some places reach a height of 7 kilometers.

Currently, all Martian volcanoes are not active. Traces of volcanic ash found on the slopes of other mountains suggest that Mars was once volcanically active.

A typical landscape of Mars is the Martian desert.

Sand dunes, giant canyons and fissures have been photographed on Mars, as well as meteorite craters. The most grandiose canyon system - the Mariner Valley - stretches for almost 4,500 kilometers (a quarter of the planet's circumference), reaching a width of 600 kilometers in width and 7-10 kilometers in depth.

Soil of Mars

The composition of the surface layer of the Martian soil, according to the data of the landers, is different in different places.

The soil mainly consists of silica (20-25%), containing an admixture of iron oxide hydrates (up to 15%), giving the soil a reddish color. The soil contains significant impurities of sulfur, calcium, aluminum, magnesium, and sodium compounds. The ratio of acidity and some other parameters of Martian soils are close to those of the Earth, and it would theoretically be possible to grow plants on them.

From reports by lead research chemist Sam Kunaves:

“In fact, we found that the soil on Mars meets the requirements and also contains necessary elements for the emergence and maintenance of life, both in the past and in the present, and in the future ... .. Such soil is quite suitable for growing various plants, such as asparagus. There is nothing here to make life impossible. On the contrary, with each new study, we find additional evidence in favor of the possibility of its existence.”

Interesting phenomena on Mars

The Mars Odyssey spacecraft has detected active geysers at the south polar cap of Mars. Jets of carbon dioxide with spring warming break up to a great height, carrying dust and sand with them. The spring melting of the polar caps leads to a sharp increase in atmospheric pressure and the movement of large masses of gas to the opposite hemisphere.

The speed of the winds blowing at the same time is 10-40 m/s, sometimes up to 100 m/s. The wind lifts from the surface a large number of dust, leading to dust storms. Strong dust storms almost completely hide the surface of the planet. Dust storms have a noticeable effect on the temperature distribution in the Martian atmosphere.

After the landings of automatic vehicles on the surface of Mars, it became possible to conduct astronomical observations directly from the surface of the planet.

The picture of the night sky of Mars (and astronomical phenomena observed from the planet) differs from the earth's and in many ways seems unusual and interesting.

For example, at noon the sky of Mars is yellow-orange. The reason for such differences from the color scheme of the earth's sky is the properties of the thin, rarefied atmosphere of Mars containing suspended dust.

Presumably, the yellow-orange coloration of the sky is caused by the presence of 1% magnetite in dust particles constantly suspended in the Martian atmosphere and raised by seasonal dust storms. Duration of storms can reach 50-100 days.

Evening dawn on Mars turns the sky a fiery red or deep orange.

Mars is the fourth planet in our solar system and the second smallest after Mercury. Named after the ancient Roman god of war. Its nickname "Red Planet" comes from the reddish hue of the surface, which is due to the predominance of iron oxide. Every few years, when Mars is in opposition to Earth, it is most visible in the night sky. For this reason, people have observed the planet for many millennia, and its appearance in the sky has played a large role in the mythology and astrological systems of many cultures. In the modern era, it has become a real treasure trove. scientific discoveries that have expanded our understanding of the solar system and its history.

Size, orbit and mass of Mars

The radius of the fourth planet from the Sun is about 3396 km at the equator and 3376 km in the polar regions, which corresponds to 53% And although it is about half as much, the mass of Mars is 6.4185 x 10²³ kg, or 15.1% of the mass of our planet. The inclination of the axis is similar to that of the earth and is equal to 25.19° to the plane of the orbit. This means that the fourth planet from the Sun also experiences the changing seasons of the year.

At its greatest distance from the Sun, Mars orbits at a distance of 1.666 AU. e., or 249.2 million km. At perihelion, when it is closest to our star, it is 1.3814 AU away from it. e., or 206.7 million km. The red planet takes 686.971 Earth days, which is equivalent to 1.88 Earth years, to complete an orbit around the Sun. In Martian days, which on Earth are equal to one day and 40 minutes, a year lasts 668.5991 days.

Soil composition

With an average density of 3.93 g/cm³, this characteristic of Mars makes it less dense than Earth. Its volume is about 15% of the volume of our planet, and its mass is 11%. Red Mars is a consequence of the presence of iron oxide on the surface, better known as rust. The presence of other minerals in the dust provides for the presence of other shades - gold, brown, green, etc.

This terrestrial planet is rich in minerals containing silicon and oxygen, metals and other substances that are usually found in rocky planets. The soil is slightly alkaline and contains magnesium, sodium, potassium and chlorine. Experiments carried out on soil samples also show that its pH is 7.7.

Although liquid water cannot exist on due to its thin atmosphere, large concentrations of ice are concentrated within the polar caps. In addition, from the pole to 60° latitude, the permafrost belt extends. This means that water exists under for the most part surface as a mixture of its solid and liquid state. Radar data and soil samples confirmed the presence also in the middle latitudes.

Internal structure

The 4.5 billion year old planet Mars consists of a dense metallic core surrounded by a silicon mantle. The core is composed of iron sulfide and contains twice as many light elements as the Earth's core. The average thickness of the crust is about 50 km, the maximum is 125 km. If we take into account that the earth's crust, the average thickness of which is 40 km, is 3 times thinner than the Martian one.

Modern models of its internal structure suggest that the core size in radius is 1700-1850 km, and it consists mainly of iron and nickel with approximately 16-17% sulfur. Due to its smaller size and mass, gravity on the surface of Mars is only 37.6% of Earth's. here it is 3.711 m/s², compared to 9.8 m/s² on our planet.

Surface characteristics

Red Mars is dusty and dry from above, and geologically it closely resembles Earth. It has plains and mountain ranges, and even the largest sand dunes in the solar system. Here is also the highest mountain - the shield volcano Olympus, and the longest and deepest canyon - the Mariner Valley.

Impact craters are typical elements of the landscape with which the planet Mars is dotted. Their age is estimated in billions of years. Due to the slow rate of erosion, they are well preserved. The largest of them is the Hellas Valley. The circumference of the crater is about 2300 km, and its depth reaches 9 km.

Gullies and channels can also be seen on the surface of Mars, and many scientists believe that water once flowed through them. Comparing them with similar formations on Earth, it can be assumed that they are at least partially formed by water erosion. These channels are quite large - 100 km wide and 2 thousand km long.

Moons of Mars

Mars has two small moons, Phobos and Deimos. They were discovered in 1877 by the astronomer Asaph Hall and are named after mythical characters. According to the tradition of taking names from classical mythology, Phobos and Deimos are the sons of Ares, the Greek god of war, who was the prototype of the Roman Mars. The first of them personifies fear, and the second - confusion and horror.

Phobos is about 22 km in diameter, and the distance to Mars from it is 9234.42 km at perigee and 9517.58 km at apogee. This is below synchronous altitude and it takes only 7 hours for the satellite to circle the planet. Scientists have calculated that in 10-50 million years, Phobos may fall to the surface of Mars or break up into a ring structure around it.

Deimos has a diameter of about 12 km, and its distance from Mars is 23455.5 km at perigee and 23470.9 km at apogee. The satellite makes a complete revolution in 1.26 days. Mars may also have additional satellites that are smaller than 50-100 m in diameter, and there is a ring of dust between Phobos and Deimos.

According to scientists, these satellites were once asteroids, but then they were captured by the planet's gravity. The low albedo and composition of both moons (carbonaceous chondrite), which is similar to the material of asteroids, support this theory, and Phobos' unstable orbit would seem to suggest a recent capture. However, the orbits of both moons are circular and in the plane of the equator, which is unusual for captured bodies.

Atmosphere and climate

The weather on Mars is due to the presence of a very thin atmosphere, which is 96% carbon dioxide, 1.93% argon and 1.89% nitrogen, as well as traces of oxygen and water. It is very dusty and contains particulate matter as small as 1.5 microns in diameter, which turns the Martian sky a dark yellow when viewed from the surface. Atmospheric pressure varies within 0.4-0.87 kPa. This is equivalent to about 1% of Earth's at sea level.

Due to the thin layer of the gaseous envelope and the greater distance from the Sun, the surface of Mars warms up much worse than the surface of the Earth. On average, it is -46 ° C. AT winter period it drops to -143 °C at the poles, and on a summer afternoon at the equator it reaches 35 °C.

Dust storms rage on the planet, which turn into small tornadoes. More powerful hurricanes occur when dust rises and is heated by the Sun. The winds intensify, creating storms that are thousands of kilometers long and last several months. They actually hide almost the entire surface area of ​​Mars from view.

Traces of methane and ammonia

Traces of methane have also been found in the atmosphere of the planet, the concentration of which is 30 parts per billion. It is estimated that Mars should produce 270 tons of methane per year. After entering the atmosphere, this gas can exist only for a limited period of time (0.6-4 years). Its presence, despite its short lifetime, indicates that an active source must exist.

Suggested options include volcanic activity, comets, and the presence of methanogenic microbial life forms beneath the planet's surface. Methane can be produced by a non-biological process called serpentinization involving water, carbon dioxide and olivine, which is common on Mars.

Express also detected ammonia, but with relatively short time life. It is not clear what produces it, but volcanic activity has been suggested as a possible source.

Planet exploration

Attempts to find out what Mars is began in the 1960s. Between 1960 and 1969 Soviet Union launched 9 unmanned aerial vehicles to the Red Planet spacecraft but they all failed to reach their goal. In 1964, NASA began launching Mariner probes. The first were "Mariner-3" and "Mariner-4". The first mission failed during deployment, but the second, launched 3 weeks later, successfully completed the 7.5 month journey.

Mariner 4 took the first close-up images of Mars (showing impact craters) and provided accurate data on atmospheric pressure on the surface and noted the absence of a magnetic field and a radiation belt. NASA continued the program with the launch of another pair of flyby probes, Mariner 6 and 7, which reached the planet in 1969.

In the 1970s, the USSR and the USA competed to be the first to launch an artificial satellite into Mars orbit. The Soviet M-71 program included three spacecraft - Kosmos-419 (Mars-1971C), Mars-2 and Mars-3. The first heavy probe crashed during launch. Subsequent missions, Mars 2 and Mars 3, were a combination of an orbiter and a lander and were the first stations to make an extraterrestrial landing (other than the Moon).

They were successfully launched in mid-May 1971 and flew from Earth to Mars for seven months. On November 27, the Mars 2 lander crash-landed due to an onboard computer failure and became the first man-made object to reach the surface of the Red Planet. On December 2, Mars-3 made a regular landing, but its transmission was interrupted after 14.5 seconds of broadcast.

Meanwhile, NASA continued the Mariner program, and in 1971 probes 8 and 9 were launched. Mariner 8 crashed into the Atlantic Ocean during launch. But the second spacecraft not only reached Mars, but also became the first successfully launched into its orbit. While the dust storm lasted on a planetary scale, the satellite managed to take several photographs of Phobos. As the storm subsided, the probe took pictures that provided more detailed evidence that water once flowed on the surface of Mars. It was found that a hill called the Snows of Olympus (one of the few objects that remained visible during a planetary dust storm) is also the most high education in the solar system, which led to its renaming to Mount Olympus.

In 1973, the Soviet Union sent four more probes: the 4th and 5th Mars orbiters, as well as the Mars-6 and 7 orbital and descent probes. All interplanetary stations, except Mars-7, transmitted data , and the Mars-5 expedition was the most successful. Before the depressurization of the transmitter housing, the station managed to transmit 60 images.

By 1975, NASA had launched Viking 1 and 2, which consisted of two orbiters and two landers. The mission to Mars was aimed at searching for traces of life and observing its meteorological, seismic and magnetic characteristics. The results of biological experiments aboard the reentry Vikings were inconclusive, but a reanalysis of the data published in 2012 suggested signs of microbial life on the planet.

Orbiters have provided additional data confirming that water once existed on Mars - large floods have formed deep canyons thousands of kilometers long. In addition, patches of branching streams in the southern hemisphere suggest that precipitation once fell here.

Resumption of flights

The fourth planet from the sun was not explored until the 1990s, when NASA sent Mars mission Pathfinder, which consisted of the spacecraft that landed the station with the Sojourner moving probe. The craft landed on Mars on July 4, 1987, and proved the viability of technologies that would be used on future missions, such as airbag landings and automatic obstacle avoidance.

The next mission to Mars is the MGS mapping satellite, it reached the planet on September 12, 1997 and began operation in March 1999. During one full Martian year, from a low altitude almost in a polar orbit, it studied the entire surface and atmosphere and sent more data about the planet than all previous missions combined.

On November 5, 2006, the MGS lost contact with Earth and NASA's recovery efforts were terminated on January 28, 2007.

In 2001, the Mars Odyssey Orbiter was sent to find out what Mars is. Its goal was to search for evidence of the existence of water and volcanic activity on the planet using spectrometers and thermal imagers. In 2002, it was announced that the probe had detected large amounts of hydrogen, evidence of huge ice deposits in the top three meters of soil within 60° of the south pole.

June 2, 2003 launched "Mars Express" - a spacecraft consisting of a satellite and a descent probe "Beagle-2". It went into orbit on December 25, 2003, and the probe entered the planet's atmosphere on the same day. Before the ESA lost contact with the lander, the Mars Express Orbiter confirmed the presence of ice and carbon dioxide at the south pole.

In 2003, NASA began exploring the planet under the MER program. It used two rovers Spirit and Opportunity. The mission to Mars had the task of examining various rocks and soils in order to find evidence of the presence of water here.

The Mars Reconnaissance Orbiter (MRO) was launched on 08/12/05 and reached the planet's orbit on 03/10/06. On board the device are scientific instruments designed to detect water, ice and minerals on and below the surface. In addition, MRO will support future generations of space probes by monitoring Mars weather and surface conditions daily, searching for future landing sites, and testing a new telecommunications system that will speed up communication with Earth.

On August 6, 2012, NASA's Mars Science Laboratory MSL and the Curiosity rover landed in Gale Crater. With their help, many discoveries have been made regarding local atmospheric and surface conditions, and organic particles have also been discovered.

On November 18, 2013, in another attempt to find out what Mars is, the MAVEN satellite was launched, the purpose of which is to study the atmosphere and relay the signals of robotic rovers.

Research continues

The fourth planet from the Sun is the most studied in the solar system after Earth. Currently, the Opportunity and Curiosity stations operate on its surface, and 5 spacecraft operate in orbit - Mars Odyssey, Mars Express, MRO, MOM and Maven.

These probes have been able to transmit incredibly detailed images of the Red Planet. They helped discover that there was once water there, and confirmed that Mars and Earth are very similar - they have polar caps, seasons, an atmosphere, and the presence of water. They also showed that organic life could exist today and most likely existed before.

Humanity's obsession with learning what Mars is unabated, and our efforts to study its surface and unravel its history are far from over. In the coming decades, we will probably continue to send rovers there and send a man there for the first time. And over time, given the availability of the necessary resources, the fourth planet from the Sun will someday become habitable.