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 planet terrestrial group rich in minerals containing silicon and oxygen, metals and other substances that are usually part of 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 most of the surface as a mixture of its solid and liquid states. 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 Earth's crust, whose average thickness is 40 km, is 3 times thinner than the Martian one.
Modern models of it internal structure the core is thought to have a radius of 1700-1850 km and is composed primarily 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. He 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 found ammonia, but with a relatively short pot 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 spacecraft to the Red Planet, but they all failed to reach the 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 magnetic field and 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 descent vehicle made an emergency landing due to a failure of the on-board computer 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, sections of branched flows in southern hemisphere suggest that there was some rainfall here.
Resumption of flights
The fourth planet from the sun was not explored until the 1990s, when NASA sent the Mars Pathfinder mission, which consisted of a spacecraft that landed a station with the moving Sojourner 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 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.
The orbit of Mars is elongated, so the distance to the Sun changes during the year by 21 million km. The distance to the Earth is also not constant. During the Great opposition of the planets, which occur once every 15-17 years, when the Sun, Earth and Mars line up, Mars approaches the Earth as close as 50-60 million km. The last Great Confrontation was in 2003. The maximum distance of Mars from the Earth reaches 400 million km.
A year on Mars is almost twice as long as an Earth year - 687 Earth days. The axis is inclined to the orbit - 65 °, which leads to a change in seasons. The period of rotation around its axis is 24.62 hours, i.e., only 41 minutes more than the period of rotation of the Earth. The tilt of the equator to the orbit is almost like that of the Earth. This means that the change of day and night and the change of seasons on Mars proceeds in much the same way as on Earth.
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 and is in a liquid state. Mars has a thick crust 100 km thick. Between them is a silicate mantle enriched in iron. The red color of Mars is precisely due to the fact that half of its soil consists of iron oxides. The planet seemed to be "rusted".
The sky over Mars is dark purple, and bright stars visible even during the day in calm, calm weather. The atmosphere has the following composition (Fig. 46): carbon dioxide - 95%, nitrogen - 2.5, atomic hydrogen, argon - 1.6%, the rest - water vapor, oxygen. In winter, carbon dioxide freezes, turning into dry ice. There are rare clouds in the atmosphere, and fogs over lowlands and at the bottom of craters in the cold season.
Rice. 46. The composition of the atmosphere of Mars
The average pressure of the atmosphere at the surface level is about 6.1 mbar. This is 15,000 times less than at and 160 times less than at the surface of the Earth. In the deepest depressions, the pressure reaches 12 mbar. The atmosphere of Mars is very thin. Mars is a cold planet. The lowest recorded temperature on Mars is -139°C. The planet is characterized by a sharp temperature drop. The temperature range can be 75-60 °C. Mars has climate zones similar to those on Earth. In the equatorial belt at noon the temperature rises to +20-25 °С, and at night it drops to -40 °С. In the temperate zone in the morning the temperature is 50-80 °C.
It is believed that a few billion years ago, Mars had an atmosphere with a density of 1-3 bar. At this pressure, water should be in a liquid state, and carbon dioxide should evaporate, and a greenhouse effect could occur (as on Venus). However, Mars was gradually losing its atmosphere due to its low mass. The greenhouse effect decreased, permafrost and polar caps appeared, which are still observed today.
Mars is home to the highest volcano in the solar system, Mount Olympus. Its height is 27,400 m, and the diameter of the base of the volcano reaches 600 km. This is an extinct volcano, which most likely spewed lava about 1.5 billion years ago.
General characteristics of the planet Mars
Currently, no active volcano has been found on Mars. Near Olympus there are other giant volcanoes: Mount Askrian, Mount Pavlina and Mount Arsia, whose height exceeds 20 km. The lava flowing out of them, before hardening, spread in all directions, so volcanoes are shaped more like cakes than cones. There are sand dunes on Mars, giant canyons and faults, as well as meteorite craters. The most grandiose canyon system is the Mariner Valley, 4,000 km long. In the past, rivers could flow on Mars, which left the channels that are currently observed.
In 1965, the American probe Mariner 4 transmitted the first images of Mars. The first Mars map. And in 1997 the American spaceship delivered a robot to Mars - a six-wheeled cart 30 cm long and weighing 11 kg. The robot was on Mars from July 4 to September 27, 1997, studying this planet. Programs about his movement were broadcast on television and on the Internet.
Mars has two moons, Deimos and Phobos.
The assumption that Mars has two satellites was expressed in 1610 by a German mathematician, astronomer, physicist and astrologer Johannes Kepler (1571 — 1630), who discovered the laws of planetary motion.
However, the satellites of Mars were discovered only in 1877 by an American astrologer Asaph Hall (1829-1907).
The weight of Mars is about 6.4169 x 1023 kg, which is about 10 times less than the mass of the earth.
The planet Mars bears the name of the ancient Roman god of war Mars - according to legend, precisely because of its reddish-"bloody" color. In relation to the Sun, Mars is in fourth place - between the nearest neighbors Earth and Jupiter. The length of the "path" between Mars and the Sun is about 228 million kilometers. In terms of its dimensions, this red planet is number seven among the other planets. Today we will find out how much Mars weighs compared to the rest of the planets, as well as other Interesting Facts"from the life" of this celestial body.
A little about Mars
Mars has long been of great interest to world scientists, since its "temperament" is very similar to the earth. Indeed, the Martian surface is covered with a layer of loose rocks (regoliths), which contain a lot of iron, mineral dust and stones. The composition of the Earth's soil is almost the same, except that it contains much more organic matter.
The weight of Mars is 6.4169 x 1023 kg
According to research, in the past, Mars had rivers, lakes, and even entire oceans. However, over time, the water completely evaporated, and today the liquid on the Red Planet is stored only underground and on the polar "caps" - in the form of ice.
The atmosphere of Mars contains 95% carbon dioxide and is highly rarefied. In addition, the Martian "air" is filled with small dust particles, giving it a reddish tint. The Martian climate is characterized by dust storms. There is a theory that these hazardous weather events result from the absorption of sunlight by fine dust particles. As a result, the atmosphere of Mars heats up and a global storm rises above the planet.
Mars and Earth - comparative characteristics and parameters
- The size. The diameter of the Red Planet is 6792 km (along the equator), which is two times less than the Earth's - this figure near the Earth is 12756 km. So, Earth is about 1.877539 times larger than Mars. If we compare the entire area of \u200b\u200bthe earth's land and the surface of Mars, then these figures will be almost equal to each other.
- Weight. Mars has a relatively small mass, about 10 percent of the Earth's mass. For comparison: Mars weighs 6.4169 x 10 23 kg, and the weight of the Earth is 5.9722 x 10 24 kg. In addition, the force of gravity on the Martian surface is less than the earth's by about 38%. Therefore, all objects on Mars will weigh less than on Earth. For example, if a child on the "native" planet weighs 32 kg, then on Mars its weight will be only 12 kg.
- Volume and Density. It is known that the average density of Mars is 3.94 g/cm 3 , and that of the Earth is approximately 5.52 g/cm 3 . As you can see, compared to the Earth, the density of the Red Planet is quite low. After all, this indicator directly depends on the mass, and the mass of Mars is only 10% of the earth. As for the volume of Mars, it is equal to only 15% of the earth's volume. If we imagine the Earth as a hollow ball, then to fill it we need six such small "balls" as Mars.
- The length of the orbit and the speed of movement of the planets in orbit. The Earth's orbit is 939,120,000 km, and that of Mars is 1,432,461,000 km. The orbital speed of Mars is 107,218 km/h, and that of the Earth is 86,676 km/h. So the duration of one complete revolution of Mars is about 687 Earth days.
- Seasons. It has been scientifically proven that a Martian day lasts 40 minutes longer than an Earth day. The number of seasons on the two planets is the same, since the axial tilts are almost the same (Earth has 23.5˚, Mars has 25˚). However, the year on Mars is about twice as long as on Earth, so the seasons are also longer.
The mass of Mars and other planets of the solar system - a comparative analysis
As can be seen from the table, in the solar system, Mars is a fairly small planet in mass, only Mercury is smaller than it.
Is there life on Mars?
This question worried many generations of earthlings. After all, Mars contains all the necessary components for the origin of life - chemical elements(carbon, hydrogen, oxygen, nitrogen), energy source and water.
In addition, back in 1996, scientists found evidence of life on Mars at the level of microorganisms, including various complex organic molecules, grains of the mineral magnetite and microscopic compounds resembling petrified microbes. Of course, the opinions of scientists on this issue differ, but so far no evidence has been found of the complete absence of life on Mars.
So, now we know how much Mars weighs, its comparative characteristics with the rest of the celestial "inhabitants" of the solar system, as well as other interesting facts.
Mars is the fourth planet from the sun. Because of its distinctly red color in the sky, the color of blood, the Greeks named it after their god of war - Ares. The Romans liked the comparison with the god of war and they willingly adopted it, although they called it in their own way - Mars. Other civilizations also named this planet by visual impression, for example, the Egyptians called Mars “Her Desher”, which means “red”, and the ancient Chinese astronomers referred to it as a “fiery star”.
Dawn on Mars. When viewed from the surface of the red planet, it no longer seems so red to us. In any case, her sky is ... bluish
Orbital characteristics of Mars
The axis of Mars, like the axis of the Earth, is tilted relative to the sun, which automatically implies the presence of seasons on the planet. However, since Mars moves around the Sun not in a round, but in an elliptical orbit (by the way, the most elongated among the planets solar system), all seasons, there are also two types at once. When Mars is closest to the sun and facing it with the southern hemisphere, the summer will be short but hot, and the northern hemisphere will have the same short but cold winter. When Mars is farther from the sun and the northern hemisphere is facing it, summer and winter will be long, without temperature fluctuations.
The tilt of the axis of Mars can change quite a lot, because unlike the Earth, it does not have an impressive “counterweight” (the Moon) that stabilizes the system. Theoretically, such jumps can have a very large impact on the planet's climate. In particular, it is assumed that it is the change in the inclination of the planet's axis that affects the sharp emissions of methane from the planet's interior into its atmosphere, which in the past may have caused periods of sharp warming.
Average distance from the sun: 227,936,640 km. (1.524 times farther than Earth).
Perihelion (closest point to the sun): 206,600,000 km (1,404 times farther than Earth).
Aphelion (farthest point from the sun): 249,200,000 km (1.638 times farther than Earth).
Physical characteristics of Mars
The famous red color of Mars is due to loose iron-rich dust that covers the entire surface of the planet, if you make some assumptions, then without organic materials, in millions of years, the soil of our planet would look something like this.
Now, that water cannot exist on its surface in a liquid state, but judging by the soil samples, it used to be much warmer here, and rivers flowed on the surface of the planet. In any case, the beds of the Martian rivers that have dried up to date, speaking of their not small sizes - up to 100 km wide and up to 2000 km long. Not bad for a planet that's about half the size of the Earth and 10 times the mass!
Typical - flat plains and lowlands. Mars does not have plate tectonics, so the diverse landscape on its surface is nowhere to be found. North hemisphere planets in average height, slightly lower than the southern one. It is assumed that once most of these northern lowlands of the planet were occupied by the Martian ocean.
The number of craters on Mars varies dramatically depending on the location. Most of the surface of the southern hemisphere of the planet has many craters, among which Hellas stands out, 2300 km wide, while in the northern hemisphere it is younger and therefore has fewer craters. In general, in terms of size, Mars is a planet of contrasts. On purpose, you can’t imagine that on a planet almost entirely covered with plains, there would be both the highest volcano in the solar system (Mount Olympus, 27 km!) And the longest canyon system (Marine Valley, 4000 km!).
Some craters have unusual "streaks" around them, reminiscent of hardened mud. Theoretically, this could mean that there is still a lot of water under the surface of Mars in the form of ice, which heats up and splashes onto the surface during a powerful impact.
Both poles of the planet are covered with snow caps, although the snow here is not quite ordinary - it is a condensate of carbon dioxide (“dry ice”) that freezes and falls as precipitation. However, under a layer of gas, the usual water ice is also hidden. During the summer period, the northern snow cap of Mars may melt completely, the southern one never melts completely.
Some volcanoes have multiple craters, suggesting that they erupted recently, leaving lava to cover older craters.
The volcanoes of Mars are one of the "wonders" of the solar system. They are so huge because the molten rock manages to find an exit to the surface of the planet, only at a few points.
Composition and structure of the surface and atmosphere of Mars
The composition of the atmosphere of Mars
The atmosphere of Mars is about 100 times thinner than Earth's. According to NASA, it is composed of 95.32% carbon dioxide, 2.7% nitrogen, 1.6% argon, 0.13% oxygen, 0.08% carbon monoxide, and trace amounts of water, nitrogen, neon, heavy hydrogen, krypton and xenon.
Mars magnetic field
At present, there is no global planetary field on Mars, but there are local areas of the surface where the magnetic field is not inferior, if not superior to that of the earth. These “islands” are the remains of an ancient planetary magnetic field that existed 4.5-3.5 billion years ago..
The chemical composition of the interior of Mars
Mars most likely has a solid core made up of iron, nickel, and sulfur. The mantle of Mars is similar in composition to Earth's and includes various compounds of silicon, oxygen, iron and magnesium. The crust of the planet is represented by volcanic basalt rocks, which are also widespread in the earth and lunar crust. However, the composition of the Earth and Martian crust is not identical - if on Mars the main element of the crust is basalt, then on Earth it is silica.
Moons of Mars
Mars has two satellites - Phobos and Deimos, discovered by the astronomer Asaph Hall in 1877. The names of the satellites are translated from Greek as "Fear" and Horror. However, for the sons of the god of war, the names are quite normal, right?
Compared to our Moon, Phobos and Deimos do not look at all representative - the diameter of Phobos in the widest part is 27 km, and Deimos is 15 km. Both satellites have irregular shape, since their gravity is too small to “compress” themselves into a lump, giving a spherical shape.
The composition of both satellites of Mars is the same - stone interspersed with ice. Although both of them have traces of meteorite impacts on the surface, the surface of Phobos is much more heterogeneous, covered with a network of cracks, in addition, it also has a large crater about 10 km wide, or almost half the width of the satellite itself.
Like our moon, Martian satellites always face it on one side.
While it remains unclear where Phobos and Deimos came from, but most likely before being retrained as the moons of Mars, both satellites were ordinary asteroids captured by the gravity of the red planet. Be that as it may, both Martian moons are a temporary phenomenon in the sky of the red planet. At least, this is true for Phobos, which is getting closer to Mars with each orbit, overcoming a “ridiculous” distance of 1.8 meters in a year. However, in 50 million years, if things continue at the same pace, Phobos will either crash into Mars or break up into small fragments that form a ring around the planet.
The moons of Mars are Phobos and Deimos. Ordinary pieces of stone bear little resemblance to our moon
Research and exploration of Mars
The first person to initiate the “instrumental” study of Mars was Galileo Galilei, who observed the planet through a telescope in 1609. For the next three and a half centuries, the telescope became the main (and only) study of Mars, with its help a lot of discoveries were made, but ... it’s better to touch with robotic arms once than to see, right? The “real” study of Mars began only when humanity was able to send automatic research stations to it, in the second half of the 20th century.
Successful missions to explore Mars
The first “space robot” that laid the foundation for the study of Mars was automatically interplanetary stations Mariner-4(USA, 1964), Mariner-6 and 7 (USA, 1969). In principle, the very first flights showed the picture as it is - the red planet turned out to be a barren world, without any signs of life on the surface. Soviet space stations Mars-2(USSR, 1971) and Mars-3(USSR, 1971) confirmed the same truth, but they did not advance much further - both stations fell into the very heart of Martian dust storms and the task of compiling the first map of the Martian surface was not completed by them.
In 1973 Mariner 9(USA) entered the orbit of Mars, after which he managed to map about 80% of the planet's surface, as well as discover the largest Martian volcanoes and canyons, the most extensive of which was named after a family of American research vehicles - Mariner Valley.
Descent vehicle Viking-1(USA, 1976) was the first man-made vehicle to successfully land on the surface of Mars. He transmitted the first photographs of the surface of Mars to earth, but did not find any evidence of the existence of life on this planet. His twin brother Viking-2 also landed successfully in the same year, carried out numerous soil tests, but also found no signs of life.
The next two ships to successfully reach the surface of Mars were "Mars Pathfinder"(Mars Pathfinder, Pathfinder, 1996), and "Mars Global Surveyor"(Mars Global Surveyor, 1996). At the same time, the Pathfinder mission included a small wheeled rover “ Sojourner” (Sojourner, “The Alien (or rather, the “Zhivalka” :))”) is the first rover to successfully complete a soil analysis mission on another planet.
Went to Mars in 2001 "Mars Odysseus"(Mars Odyssey, USA), who discovered a large amount of water ice under the surface of Mars, at a depth of more than one meter below the surface.
In 2003, NASA launched two similar rovers to Mars at once: “ Spirit” (Spirit, “Spirit”) and “ Possibility”(Opportunity, “Opportunity”), which successfully landed in different areas of the red planet and in both areas found clear signs that water really once flowed on the surface of Mars.
In 2008, NASA sent a lander to Mars as part of the Mars Scout mission. Phoenix” (Phoenix), who landed on the planet's northern plains and searched for water.
In 2011, NASA sent a fourth rover, known as “ Curiosity"(Mars Curiosity, Curiosity)". Of all the rovers, this was the most advanced and largest (weight on earth 899 kg, on Mars 340 kg). This rover - in fact, a whole mobile automated laboratory, conducted a huge range of analyzes of the soil and atmosphere of the red planet and gave scientists a lot of information about the present and past of Mars. Having started work in 2012, as of 2017, Curiosity still maintains some efficiency and continues its mission.
In 2014, an apparatus entered the orbit of Mars MAVEN(Mars Atmosphere and Volatile EvolutioN - "The evolution of the atmosphere and volatile substances on Mars") - the second part of the Mars Scout project, which made it possible to more accurately determine the reasons for the loss of most of Mars' atmosphere. Also in 2014, an Indian satellite reached the orbit of Mars. Mangalyan” delivered to the target with the help of a Russian missile.
The Opportunity rover in a typical Martian landscape. The artist really overdid it and got carried away, since most of the surface of Mars is still covered not with mountains, but with almost flat plains dotted with stones.
Planned missions to Mars
- “insight” (InSight, NASA, 2018) is a dual mission of a lander and an orbiter that will study the interior of Mars.
- “Mars 2020” (Mars 2020 Rover Mission, NASA, 2020) is the “receiver” of the Curiosity rover, which will replace the old man at his post.
Among the objects of the solar system, Mars continues to be the most curious and most explored planet. For all the time of close study by man of our near space, only the fourth planet of the solar system has received such attention. The reason for this heightened interest to our neighbor lies not only in its relative proximity to our world. The red planet is of interest to humanity in terms of the possibility of exploring extraterrestrial space.
The data that is available today about Mercury and Venus indicate that these are alien, hostile worlds for us. For these planets, nature has prepared the fate of physical and chemical laboratories. Mars, in many respects, is no longer so gloomy and lifeless. It is not without reason that the literary laurels of the motherland of the first extraterrestrial civilization. Why is Mars so interesting to us? What is a person really dealing with, turning his gaze to a small, reddish star in the night sky.
Description of the red planet
Of the entire list of planets in the solar system, Mars is perhaps the only one space object, which a person can reach today. It is the second closest planet to us in the solar system. Even the level of technological development that human civilization has reached makes it possible to make plans for the exploration of Mars and the implementation of a manned flight to the fourth planet of our star system. Approximately for the implementation of this large-scale and grandiose program, it will take another 10-15 years. However, if we compare the preparatory measures now under way in this direction with the program for a visit by man to the Moon, the difference is obvious.
According to many data obtained recently with the help of automatic space probes and rovers, it is possible that life could have existed on the red planet millions of years ago. Not without reason, studying the obtained images of the surface of the planet Mars, scientists of all stripes are unanimous in their opinion - our neighbor is not hopeless. There are all prerequisites to believe that the fourth planet could be another oasis of life in our solar system. This is facilitated by the astrophysical parameters of the planet, data on the Martian atmosphere, and the climatic pattern on the surface of our neighbor.
In addition, if the Martian poles are covered with ice caps, the version about the presence of liquid water in the bowels of the planet has the right to life. If it is proved that liquid water has every chance of being in the nature of the red planet, then the question of finding life forms in this harsh place is just a matter of time.
Confidence to supporters of the usefulness of Mars for human exploration is given by information about the composition of the Martian air and astrophysical parameters similar to those of the Earth. Even under the condition that the atmosphere of the planet is far in its composition from the earth's air gap, we can talk about relatively acceptable conditions. A highly rarefied atmosphere does not inspire optimism, but to some extent it is better than the picture that we observe on Mercury or on hot Venus. Scientists believe that according to climatic parameters on Mars, the weather is quite tolerable. Severe frosts with temperatures down to -170°C in the polar regions give way to tropical heat in the equatorial regions. In summer days the temperature reaches +20°C. However, in winter time and especially at night, the temperature can drop to -125°C.
In other words, with the appropriate technical and physical training of a person, the Martian environment can be habitable. Do not discount the fact that such climatic conditions were the result of a cosmic cataclysm. It is possible that in the distant past of the planet, the climate on the planet was warmer and Martian life was rampant on the planet. This cannot be said in relation to other planets of the terrestrial group, where the slightest hints of the existence of conditions for the origin of life are completely absent.
The information that the scientific community has collected today gives every reason to consider the Red Planet as a convenient springboard for subsequent space exploration. Numerous works of scientists, flights of automatic probes to the planet and delivery of rovers to Mars made it possible to obtain mass useful information. We now know almost everything about the Martian soil, we have an idea of the most severe dust storms. Scientists have obtained detailed images of almost the entire surface of the planet, including the northern and southern polar caps. It remains only to process the tons of information received and draw the appropriate conclusions.
Brief description and features of the planet
From the point of view of academic science, Mars is a pronounced terrestrial planet. The slightly elongated orbit of the planet is located 1.5 times farther from the Sun than the orbit of the Earth. At perihelion, Mars moves away from our star at a distance of 250 million km, and at aphelion, the planet Mars is separated from the Sun by a distance of 207 million km. The Red Planet is twice the size of our Earth. The diameter of the fourth planet is 6,779 km, against 12,742 km. Earth's diameter.
If Mars is only twice as large as Earth, then the mass of the Red Planet is ten times lighter than our blue beauty, 6.39E23 kg versus 5.972E24 kg. Accordingly, the acceleration free fall our neighbor is only 3.72 m/s2 against 9.807 m/s2. For all its miniature size, the relief of the planet is quite diverse. The Red Planet has mountains and valleys, vast depressions, deep canyons, and even meteorite craters similar to moon formations. Extinct volcanoes have been discovered on the surface of our neighbor, indicating the stormy youth of Mars. Here is the highest volcano in the solar system - Mount Olympus. Its top rests against the Martian sky, reaching 26 kilometers in height. This extinct volcano holds the record, with a height of 2.5 times the relative height of the terrestrial volcano Mauna Kea.
However, despite the varied terrain, the landscape on Mars is rather boring and monotonous. Mountain ranges are replaced by endless rocky deserts. The bright areas on the surface of the planet are called the continents, while the dark areas are the Martian seas. These elements of the Martian relief occupy more than 70% of the area of the southern hemisphere of Mars.
With all the monotony of the Martian surface, the planet has its own feature. Both hemispheres of Mars differ significantly in both morphological features, and from the point of view of the intensity of external influence. In the northern hemisphere, the relief is dominated by valleys and smooth plains, although the surface of the planet in this part is below average. The southern hemisphere is dominated by meteorite craters and the surface itself is elevated. This fact to some extent explains the presence of tectonic plates that moved in ancient times. The dull Martian landscape is brightened up only by the polar caps available at the north and south poles of the planet.
Like all terrestrial planets, Mars has a classical structure:
- crust, 100 km thick at the poles and 8 km thick in the equatorial region in the region of the Hellas depression;
- an intermediate layer consisting of semi-liquid rocks;
- silicate mantle 1300-1500 km thick;
- an iron core with a diameter of 2960 km, which is half liquid.
The Red Planet has its own atmosphere. Its composition is dominated by carbon dioxide. Less air mass The planet contains nitrogen, hydrogen and oxygen. The presence of water vapor is very limited. Due to the strong rarefaction, the atmospheric pressure on Mars is 150 times less than the earth's pressure, only 6.1 millibars. The thickness of the gaseous shell around the planet is 110 km.
Assessing the physical information about the planet, it is worth paying attention to the astrophysical parameters of Mars, which are in many respects similar to the terrestrial parameters. The fourth planet makes a complete revolution around our star in 687 Earth days. At the same time, the speed of rotation of the red planet around its own axis is almost equal to the speed of rotation of the Earth - 24 hours and 37 minutes. In other words, time on the planet looks the same as on Earth. Due to its tilt and speed of rotation, Mars has a change of seasons, which is quite rare for other planets in the solar system. The length of the seasons on the surface of our neighbor is different. In the northern hemisphere, summer lasts 177 Martian days, while in the southern hemisphere, summer is 21 days shorter.
Brief description and nature of exploration of Mars
Since the first flights into space, man has not abandoned attempts to start studying neighboring planets. The American space probe Mariner 4 was the first to head to the Red Planet, which for the first time photographed Mars from a close distance, flying past the planet. Subsequent missions were already more thorough and applied in nature. The American probe "Mariner-9" having reached the fourth planet, became its first artificial satellite. In 1971, the first ever landing on Mars was made by the Soviet AMS "Mars-3". Despite a successful landing, the Soviet apparatus lived only 14 seconds. Subsequent attempts to land on Mars ended in failure.
Only the American AMS "Viking-1" once again managed to make a soft landing on the planet and provide man with the first pictures of the surface of Mars. During the same expedition, for the first time, samples of Martian soil were taken by the apparatus and data on the composition of the soil were obtained. Further, with enviable regularity, Soviet and American spacecraft, automatic probes of space agencies were sent to the fourth planet. different countries including China, Japan and the European Community. Over the next 45 years from the moment of the first flight of Mariner-4 towards Mars, 48 expeditions to the Red Planet were organized from the Earth. Of this number, almost half of the missions ended in failures.
To date, the following devices continue to explore the planet:
- the orbital satellite of Mars - the American apparatus "Mars-Odyssey";
- from the planet's orbit, the automatic probe of the European Space Agency "Mars-Express";
- American orbiter "Maven" and a satellite of the military department;
- the Indian orbital probe "Mangalyan" and the space probe "Trace Gas Orbiter" of ESA and Roscosmos.
Directly on the planet, two American rovers Opportunity and Curiosity continue to work, which have already become legendary creations of human thought. Numerous space probes, automatic Martian stations and rovers - all this equipment is an arsenal thrown by the scientific community to study the red planet.
Permanent satellites of Mars
Mars, despite its size, has two natural satellites - Phobos and Deimos, triaxial ellipsoids with dimensions of 26.8 × 22.4 × 18.4 km and 15 × 12.2 × 10.4 km, respectively.
The exact origin of these celestial bodies is unknown. The size of the Martian satellites and their shape cause numerous disputes among supporters of various theories of the origin of Phobos and Deimos. It is assumed that these are asteroids captured by the red planet at the dawn of the formation of the solar system. The supplier of material for the satellites of Mars is the asteroid belt, located between the fourth planet and Jupiter.
Proponents of another version of the origin of the satellites of the red planet are inclined to their artificial nature. Create and run two artificially created celestial bodies could have been an ancient Martian civilization.