– have small sizes and masses, the average density of these planets is several times higher than the density of water; they rotate slowly around their axes; they have few satellites (Mercury and Venus have none at all, Mars has two tiny ones, Earth has one).

The similarity of the terrestrial planets does not exclude significant differences. For example, Venus, unlike other planets, rotates in the direction opposite to its movement around the Sun, and is 243 times slower than the Earth (compare the length of the year and day on Venus). The orbital period of Mercury (i.e., the year of this planet) is only 1/3 greater than the period of its rotation around its axis (relative to the stars). The angles of inclination of the axes to the planes of their orbits for the Earth and Mars are approximately the same, but completely different for Mercury and Venus. Do you know that this is one of the reasons that determines the nature of the change of seasons. Consequently, Mars has the same seasons as the Earth (although each season is almost twice as long as on Earth).

It is possible that, due to a number of physical characteristics, distant Pluto, the smallest of the 9 planets, also belongs to the terrestrial planets. The average diameter of Pluto is about 2260 km. The diameter of Charon, the moon of Pluto, is only half the size. Therefore, it is possible that the Pluto-Charon system, like the Earth-system, is a “double planet”.

Atmospheres

Similarities and differences are also revealed when studying the atmospheres of the terrestrial planets. Unlike Mercury, which, like the Moon, is practically devoid of an atmosphere, Venus and Mars have one. Modern data on the atmospheres of Venus and Mars were obtained as a result of flights of our (“Venera,” “Mars”) and American (“Pioneer-Venera,” “Mariner,” “Viking”) spacecraft. Comparing the atmospheres of Venus and Mars with the Earth's, we see that, unlike the nitrogen-oxygen atmosphere of the Earth, Venus and Mars have atmospheres mainly consisting of carbon dioxide. The pressure at the surface of Venus is more than 90 times greater, and at Mars it is almost 150 times less than at the surface of the Earth.

The temperature at the surface of Venus is very high (about 500°C) and remains almost the same. What is this connected with? At first glance, it seems that Venus is closer to the Sun than the Earth. But, as observations show, the reflectivity of Venus is greater than that of the Earth, and therefore heats both planets approximately equally. The high surface temperature of Venus is due to the greenhouse effect. It is as follows: the atmosphere of Venus transmits the rays of the Sun, which heat the surface. The heated surface becomes a source of infrared radiation, which cannot leave the planet, since it is retained by the carbon dioxide and water vapor contained in the atmosphere of Venus, as well as the cloud cover of the planet. As a result of this, the balance between the influx of energy and its consumption into peaceful space is established at a higher temperature than that which would be on a planet that freely transmits infrared radiation.

We are accustomed to earthly clouds consisting of small drops of water or ice crystals. The composition of the clouds of Venus is different: they contain droplets of sulfur and, possibly, of hydrochloric acid. The cloud layer greatly weakens sunlight, but, as measurements performed on the Venera 11 and Venera 12 satellites have shown, the illumination at the surface of Venus is approximately the same as at the surface of the Earth on a cloudy day. Studies carried out in 1982 by the Venera 13 and Venera 14 probes showed that the sky of Venus and its landscape have Orange color. This is explained by the peculiarity of light scattering in the atmosphere of this planet.

Gas in the atmospheres of the terrestrial planets is in continuous motion. Often during dust storms that last for several months, huge amounts of dust rise into the atmosphere of Mars. Hurricane winds have been recorded in the atmosphere of Venus at altitudes where the cloud layer is located (from 50 to 70 km above the surface of the planet), but near the surface of this planet the wind speed reaches only a few meters per second.

Thus, despite some similarities, in general, the atmospheres of the planets closest to Earth differ sharply from the Earth's atmosphere. This is an example of a discovery that could not have been predicted. Common sense suggested that planets with similar physical characteristics(Earth and Venus, for example, are sometimes called “twin planets”) and at about the same distance from the Sun should have very similar atmospheres. In fact, the reason for the observed difference is related to the peculiarities of the evolution of the atmospheres of each of the terrestrial planets.

The study of atmospheres of the terrestrial group not only allows us to better understand the properties and history of the origin of the earth’s atmosphere, but is also important for solving environmental problem. For example, fogs - smogs, formed in the earth's atmosphere as a result of air pollution, are very similar in composition to Venusian clouds. These clouds, like dust storms on Mars, remind us that it is necessary to limit the emission of dust and various types of industrial waste into the atmosphere of our planet if we want to maintain conditions on Earth suitable for the existence and development of life for a long time. Dust storms, during which clouds of dust are retained in the atmosphere of Mars for several months and spread over vast areas, make one think about some of the possible environmental consequences of a nuclear war.

Surfaces

Terrestrial planets, like the Earth and the Moon, have rocky surfaces. Ground-based optical observations provide little information about them, since Mercury is difficult to see through a telescope even during elongations, and the surface of Venus is hidden from us by clouds. On Mars, even during great oppositions (when the distance between Earth and Mars is minimal - about 55 million km), occurring once every 15 - 17 years, large telescopes can be used to view details measuring about 300 km. And yet, in recent decades, it has been possible to learn a lot about the surface of Mercury and Mars, as well as to gain insight into the until recently completely mysterious surface of Venus. This became possible thanks to the successful flights of automatic interplanetary stations such as “Venus”, “Mars”, “Viking”, “Mariner”, “Magellan”, which flew near the planets or landed on the surface of Venus and Mars, and thanks to ground-based radar observations.

The surface of Mercury, replete with craters, is very similar to the Moon. There are fewer “seas” there than on the Moon, and they are small. The diameter of the Mercurian Sea of ​​Heat is 1300 km, as is the Sea of ​​Rain on the Moon. Steep ledges stretch for tens and hundreds of kilometers, probably generated by the former tectonic activity of Mercury, when the surface layers of the planet shifted and moved forward. As on the Moon, most craters were formed by meteorite impacts. Where there are few craters, we see relatively young areas of the surface. Old, destroyed craters are noticeably different from younger, well-preserved craters.

The rocky desert and many individual stones are visible in the first photo-television panoramas transmitted from the surface of Venus by the automatic stations of the “Venus” series. Radar ground observations have discovered many shallow craters on this planet, with diameters ranging from 30 to 700 km. In general, this planet turned out to be the smoothest of all the terrestrial planets, although it also has large mountain ranges and long hills, twice the size of terrestrial Tibet. The extinct volcano Maxwell is enormous, its height is 12 km (one and a half times greater than Chomolungma), the diameter of the base is 1000 km, the diameter of the crater at the top is 100 km. The Gauss and Hertz volcanic cones are very large, but smaller than Maxwell. Like rift gorges stretching along the bottom of the Earth's oceans, rift zones have also been discovered on Venus, indicating that on this planet there once occurred (and perhaps are still occurring!) active processes(eg volcanic activity).

In 1983 – 1984 Radar studies were carried out from the stations “Venera - 15” and “Venera - 16”, which made it possible to create a map and atlas of the planet’s surface (the size of the surface details is 1 – 2 km). A new step in the study of the surface of Venus is associated with the use of a more advanced radar system installed on board the American satellite Magellan. This spacecraft reached the vicinity of Venus in August 1990 and entered an elongated elliptical orbit. Regular surveys have been carried out since September 1990. Clear images are transmitted to Earth, some of them clearly show details up to 120 m in size. By May 1993, almost 98% of the planet's surface was surveyed. It is planned to complete the experiment, which includes not only photographing Venus, but also conducting other studies (gravitational field, atmosphere, etc.) in 1995.

The surface of Mars is also replete with craters. There are especially many of them in the southern hemisphere of the planet. The dark areas that occupy a significant part of the planet's surface are called seas (Hellas, Argir, etc.). The diameters of some seas exceed 2000 km. The hills, reminiscent of the earth's continents, representing light fields of orange-red color, are called continents (Tharsis, Elysium). Like Venus, there are huge volcanic cones. The height of the largest of them (Olympus) exceeds 25 km, the diameter of the crater is 90 km. The base diameter of this giant cone-shaped mountain is more than 500 km.

The fact that millions of years ago powerful volcanic eruptions occurred on Mars and surface layers shifted is evidenced by the remains of lava flows, huge surface faults (one of them, Mariner, stretches for 4000 km), numerous gorges and canyons. It is possible that it was some of these formations (for example, chains of craters or extended gorges) that Mars researchers 100 years ago mistook for “channels,” the existence of which they subsequently tried to explain for a long time by the activities of intelligent inhabitants of Mars.

The red color of Mars has also ceased to be a mystery. It is explained by the fact that the soil of this planet contains a lot of clays rich in iron.

Panoramas of the surface of the “Red Planet” were repeatedly photographed and transmitted from close range.

You know that almost 2/3 of the Earth's surface is occupied by oceans. There is no water on the surface of Venus and Mercury. There are no open bodies of water on the surface of Mars either. But, as scientists suggest, water on Mars should be at least in the form of a layer of ice forming the polar caps, or as an extensive layer permafrost. You may witness the discovery of ice reserves on Mars, or even water underneath the ice. The fact that there was once water on the surface of Mars is evidenced by the dried, channel-like winding depressions discovered there.

Compose schematic drawing planetary positions solar system relative to the Sun.

The four smaller inner planets: Mercury, Venus, Earth and Mars are terrestrial planets

Four outer planets: Jupiter, Saturn, Uranus and Neptune are giant planets. much more massive than the terrestrial planets. The largest planets of the solar system, Jupiter and Saturn;; the outer ones are smaller, Uranus and Neptune.

The terrestrial planets (Mercury, Venus, Earth, Mars) are similar in size and chemical composition. Characteristic of all terrestrial planets - the presence of a solid lithosphere. The relief of their surface was formed as a result of the action of external (impacts of bodies falling on planets at enormous speeds) and internal (tectonic movements and volcanic phenomena) factors. Also, all terrestrial planets except Mercury have an atmosphere. Distinctive feature The Earth is distinguished from other terrestrial planets by the presence of an atmosphere.

The atmospheres of Mars and Venus are very similar in composition to each other, but at the same time they differ significantly from the earth's.
Terrestrial planets have some General characteristics. They all have a solid surface and appear to be composed of a substance similar in composition, although Earth and Mercury are more dense than Mars and Venus. Their orbits in general do not differ from circular ones, only the orbits of Mercury and Mars are more elongated than those of the Earth and Venus.
Mercury and Venus are called inner planets because their orbits lie inside the Earth's; they, like the Moon, come in different phases - from new to full - and remain in the same part of the sky as the Sun. Mercury and Venus have no satellites, Earth has one moon satellite, Mars has 2 satellites - Phobos and Deimos, both are very small and differ in nature from the Moon.

MERCURY- the planet closest to the Sun in the Solar System.

As the planet closest to the Sun, Mercury receives significantly more energy from the central star than, for example, the Earth (on average 10 times). The surface of Mercury, covered with crushed basalt-type material, is quite dark. Along with craters (usually less deep than on the Moon) there are hills and valleys. Above the surface of Mercury there are traces of a very rarefied atmosphere containing, in addition to helium, also hydrogen, carbon dioxide, carbon, oxygen and noble gases (argon, neon. Mercury also has a magnetic field. The planet consists of hot , a gradually cooling iron-nickel core and silicate shell, at the boundary between which the temperature can approach 103 K. The core accounts for more than half the mass of the planet.

VENUS- the second planet from the Sun and closest to Earth in the solar system.



Venus is the only planet in the solar system whose own rotation is opposite to the direction of its revolution around the Sun. The surface of Venus is predominantly (90%) flat, although three elevated areas have been discovered. On the surface of Venus, craters, faults and other signs of intense tectonic processes occurring on it were discovered. Traces of impact bombing are also clearly visible. The surface is covered with stones and slabs of various sizes; surface rocks are similar in composition to terrestrial sedimentary rocks. The predominant proportion of the atmosphere is carbon dioxide (~ 97%); nitrogen - about 3%; water vapor - less than a tenth of a percent, oxygen - thousandths of a percent. The clouds of Venus consist mainly of 75-80 percent sulfuric acid. Venus's magnetic field is negligible. Due to its relative proximity to the Sun, Venus experiences significant tidal influences, which creates an electric field above its surface, the intensity of which can be twice that of the “fair weather field” observed above the Earth’s surface. Venus has three shells. The first of them - the crust - is approximately 16 km thick. Next is the mantle, a silicate shell that extends to a depth of about 3,300 km to the border with the iron core, the mass of which is about a quarter of the total mass of the planet.

Earth- the third planet from the Sun in the Solar System.

The Earth moves around the Sun. The Earth's surface area is 510.2 million km2, of which approximately 70.8% is in the World Ocean. Land makes up 29.2%, respectively, and forms six continents and islands. The Earth has a single satellite - the Moon. According to modern concepts, the outer core consists of sulfur (12%) and iron (88%). Finally, at depths greater than 5,120 km, seismic methods reveal the presence of a solid inner core, which accounts for 1.7% of the Earth's mass. Presumably it is an iron-nickel alloy (80% Fe, 20% Ni).

The Earth is surrounded by an atmosphere (see Earth's Atmosphere). Its lower layer (troposphere) extends to an average altitude of 14 km; The processes occurring here play a decisive role in the formation of weather on the planet. Even higher (up to about 80-85 km) is the mesosphere, above which noctilucent clouds are observed (usually at an altitude of about 85 km). For biological processes On Earth, the ozonosphere is of great importance - the ozone layer located at an altitude of 12 to 50 km. The area above 50-80 km is called the ionosphere.. If not ozone layer, radiation flows would reach the surface of the Earth, causing destruction in living organisms existing there. The Earth also has magnetic and electric fields.

MARS- the fourth planet from the Sun in the Solar System.

Since the inclination of the equator to the orbital plane is significant (25.2°), there are noticeable seasonal changes on the planet. A significant part of the surface of Mars is lighter areas (“continents”) that are reddish-orange in color; 25% of the surface are darker “seas” of gray-green color, the level of which is lower than that of the “continents”. Observations of Mars from satellites reveal clear traces of volcanism and tectonic activity - faults, gorges with branching canyons. The surface of Mars appears to be a waterless and lifeless desert, over which storms rage, raising sand and dust to a height of tens of kilometers. The atmosphere on Mars is thin and consists mainly of carbon dioxide (about 95%) and small additions of nitrogen (about 3%), argon (about 1.5%) and oxygen (0.15%). Chemical composition Mars is typical for planets Earth group, although, of course, there are specific differences. The core of Mars is rich in iron and sulfur and is small in size, and its mass is about one tenth of the total mass of the planet. The mantle of Mars is enriched in iron sulfide. The thickness of the lithosphere of Mars is several hundred km, including approximately 100 km of its crust. Two satellites orbit around Mars: Phobos (Fear) and Deimos (Horror). Gravitational fields satellites are so faint that they have no atmosphere. Meteorite craters were discovered on the surface.

Main characteristics The planets of the solar system are determined by their distance from the Sun, period of revolution around the Sun, diameter, mass and volume.

Mercury is the closest planet to the Sun and the smallest planet in the Solar System. In terms of radius, it is inferior to the satellites of Jupiter - Callisto and Ganymede, the satellite of Saturn - Titan and the satellite of Neptune - Triton. Mercury rotates around its axis with a period 1.5 times less than the period of its orbit. On the illuminated hemisphere of Mercury, the temperature reaches 700°K, and on the unlit, night side it can drop to 220°K. Television footage carried out by Mariner 10 showed that the surface of Mercury is in many ways similar to the surface of the Moon. According to optical and photoclinometric measurements, Mercury is dotted with craters no less than the Moon, if not more so. The exact dimensions of Mercury 56 have not yet been determined. Radar diameter and mass give the average density of Mercury 5.46 g/cm 3, the photoelectric Hertzsprung method is 1% more than the radar value. The data obtained indicate the significant role of the metal phase in its depths.

Numerous studies of the reflectivity of Mercury's surface indicate a high probability of containing significant amounts of FeO in its soil. This conclusion contradicts the accepted hypotheses about the conditions of condensation of Mercury. However, if these data are confirmed, then the removal of FeO to the surface as part of pyroxene will have to be considered due to basaltic volcanism. Mercury's soil is close to that of lunar highlands (-5.5% FeO), which are known to contain orthopyroxene. The largest depression discovered on Mercury has a diameter of 1,300 km. It is filled with a substance similar to the substance of the lunar seas. Formations similar to the structures of terrestrial tectonics, plates or large-scale faults are not noticeable. It is assumed that the processes of differentiation of the planet, which has an iron core, ended at the stage of its accretion.

Venus is closest in size and average density to Earth. The mass of the planet, calculated after the flight of the Mariner 2 interplanetary station, is 0.81485 Earth masses. Radar measurements led to the conclusion that Venus V Unlike other planets, it rotates in the direction opposite to the direction of its movement around the Sun. According to radar measurements, the solid part of Venus is an uneven surface. Information about the microrelief was obtained from the Venera-8 and Venera-14 landers. In general, the surface of Venus is much smoother than that of other terrestrial planets. Individual hills and individual mountain peaks are observed. Notable is one of the areas (near the equator) with a diameter of about 700 km with a depression in the middle part of 60X90 km, rising 10 km above the neighboring areas. This uplift is interpreted as a large volcanic structure similar to Earth's and Martian continental volcanoes. On Venus there is also a channel-like depression 1400 km long, 150 km wide and 2 km deep, which can be compared with similar and very common “channels” on Mars and partly with the African-Arabian rift system in East Africa. This depression or trough, 850 km to the east, penetrates into a continental-sized plateau, where it meets a weakly expressed, very narrow, wave-like depression. Venera-10 estimated the density of the Venusian rock to be 2.8±±0.1 g/cm3, typical for the Moon or Earth. Photographs of Venus obtained by Venera-9 and Venera-10 showed that the surface at the landing sites is characterized by slab-shaped and rounded matte gray massive pebbles. The pebbles are fine-grained with a dark matrix of regolith or soil.

Venus is characterized by: 1) a unique topography with a relief contrasting in higher spatial frequency, but lower magnitude than other terrestrial planets (it cannot be said that the magnitude of the relief is not similar to that of Earth, just as the surface irregularities are comparable to those of are characterized lunar seas), 2) landscape diversity - crater-like forms found in groups separated from mountain plateau areas by a large equatorial fault (isolated mountains appear to be found everywhere in areas surveyed by earth-based radars), 3) the presence of three types of volcanoes: some form large single structures comparable to the Tharsis volcano on Mars, others - smaller peaks that occur singly or in groups, others - plains similar to those on Mars and the Moon, 4) the presence of mountainous terrain and roughly defined lineaments, obviously indicating the manifestation of compression tectonics, 5) the presence of a large trough at the equator, indicating extensional tectonic activity, 6) radioactivity, which indicates that its rocks are similar to those on Earth. "Venera-9" and "Venera-10" apparently encountered basaltic rocks, and "Venera-8" - with rocks of granitic composition (the former confirm the assumption of the development of volcanism, while the latter give reason to believe the presence of more complex tectono-volcanic history), 7) the presence of two areas that were subject to geometric changes (the differences between them can be explained by the peculiarities of the processes occurring in them, which differed either in time or in speed or combinations of both; however, in all cases these processes were active enough to separate large fragments from small ones, roll around some pebbles and not affect others, and mix all this exotic material; such processes could be both ballistic impact and aeolian processes; Venus is surrounded by a thick gaseous shell).

The Earth is the largest of all the inner planets and has the largest satellite - the Moon. The composition of the nitrogen-oxygen atmosphere of the Earth differs sharply from the atmosphere of other planets. We know an incredible amount about the Earth compared to other planets.

The Moon is a natural satellite of the Earth, constituting 1/81 of its mass and moving in orbit at an average speed of 1.02 km/s, or 3680 km/h. The surface of the Moon consists of light areas formed by mountain systems and hills, and dark areas - the so-called “seas”. The largest “seas” have arbitrary names: Sea of ​​Rains, Sea of ​​Clarity, Sea of ​​Abundance, Sea of ​​Nectar, Ocean of Storms, etc. The entire surface (3.8-10 7 km 2) of the Moon is covered with many funnels of various sizes, the largest of which received the name of lunar circuses. In terms of density, the Moon is an almost homogeneous body. It is slightly asymmetrical. Its center of gravity is approximately 2 km closer to Earth than its geometric center. On

The Moon encounters highlands, irregular and annular sea basins, lineaments and grooves, craters with a diameter of thousands of kilometers to millimeters. The Moon has very weak seismicity. Apparently, the weak tremors recorded by seismographs on the surface of the Moon are caused more by falling meteorites than by tectonic activity. However, based on seismic data, four or five zones are identified. The first seismic boundary passes at a depth of 50-60 km, the second - 250 km, the third - 500 km, the fourth - 1400-1500 km. The corresponding zones are attributed to the crust, upper, middle and lower mantle, and in the center of the Moon there may be a core with a diameter of 170-350 km. These divisions are rather arbitrary, since the observed differences in the velocities of seismic waves are at the limit of the resolution of seismographs installed on the Moon.

Of all the inner planets, Mars is the farthest from the Sun, its mass is 0.108 of the mass of the Earth, its compression is 1/190.9, i.e. it is greater than that of the Earth. This indicates that its mass is less concentrated near the center than on Earth. Mars revolves around the Sun with a period of 1 year 322 proper days, the rotation axis has an inclination of 67° to the orbital plane. This causes the seasons to change at different latitudes, similar to what happens on Earth. Mars has two satellites - Deimos and Phobos - with rotation periods of 30.30 and 7.65 hours, respectively; the satellites move almost exactly in the plane of the planet's equator: Phobos is at a distance of 9,400 km, and Deimos is 23,500 km. According to Mariner 9 data, the satellites have irregular shape, the dimensions of Phobos are 25X21 km, and Deimos is 13.5X12 km; both have a low albedo (0.05), which is close in value to the albedo of carbonaceous chondrites and basalts. Phobos and Deimos are covered with numerous impact craters.

The terrestrial planets are the four planets of the solar system: Mercury, Venus, Earth and Mars. They are located in the inner region of the Solar system, in contrast to the giant planets located in outer area. According to a number of cosmogonic theories, in a significant part of extrasolar planetary systems, exoplanets are also divided into solid planets in the inner regions and gas planets in the outer regions. In structure and composition, some rocky asteroids, for example Vesta, are close to the terrestrial planets.

Main characteristics

Terrestrial planets are highly dense and consist predominantly of silicates and metallic iron (in contrast to gas planets and rock-ice dwarf planets, Kuiper belt objects and the Oort cloud). Largest planet terrestrial group - Earth - is more than 14 times less massive than the least massive gas planet - Uranus, but at the same time about 400 times more massive than the largest known Kuiper belt object.

Terrestrial planets consist mainly of oxygen, silicon, iron, magnesium, aluminum and other heavy elements.

All terrestrial planets have the following structure:

  • In the center is a core of iron mixed with nickel.
  • The mantle consists of silicates.
  • Crust formed as a result of partial melting of the mantle and also consisting of silicate rocks, but enriched in incompatible elements. Of the terrestrial planets, Mercury does not have a crust, which is explained by its destruction as a result of meteorite bombardment. Earth is different from other terrestrial planets high degree chemical differentiation of matter and the wide distribution of granites in the crust.

Two of the terrestrial planets (the farthest from the Sun - Earth and Mars) have satellites. None of them (unlike all giant planets) have rings.

Pluto - they all have small masses and sizes, their average density is several times higher than the density of water; they are able to slowly rotate around their own axes; they have a small number of satellites (Mars has two, Earth has only one, and Venus and Mercury do not have them at all).

The similarity of planets in the terrestrial group does not exclude some differences. For example, Venus rotates in reverse direction from the movement around the Sun, and two hundred and forty-three times slower than the Earth. The period of rotation of Mercury (that is, the year of this planet) is only one-third longer than the period of its rotation around its axis.

The angle of inclination of the axis to the orbital planes of Mars and the Earth is approximately the same, but completely different for Venus and Mercury. Just like Earth, there are seasons, which means so do Mars, although almost twice as long as Earth.

Perhaps distant Pluto, the smallest of the nine planets, can also be classified as a terrestrial planet. The usual diameter of Pluto was more than two thousand kilometers. Only the diameter of Pluto’s satellite Charon is only 2 times smaller. Therefore, it is not a fact that the Pluto-Charon system, like the Earth-system, is a double planet.

Similarities and differences are also found in the atmospheres of the terrestrial planets. Venus and Mars have an atmosphere, unlike Mercury, which, however, like the Moon, is practically devoid of it. Venus has a fairly dense atmosphere, mainly consisting of sulfur compounds and carbon dioxide. The atmosphere of Mars, on the contrary, is too rarefied and very poor in nitrogen and oxygen. The pressure at the surfaces of Venus is almost a hundred times more, while at Mars it is almost a hundred and fifty times less than at the surfaces of the Earth.

The heat on the surfaces of Venus is quite high (about five hundred degrees Celsius) and remains almost the same all the time. The high temperature of the surfaces of Venus is determined by the greenhouse effect. The thick, dense atmosphere releases the rays of the Sun, but traps thermal infrared radiation that comes from heated surfaces. Gas in the atmosphere of a terrestrial planet is in constant motion. Often during a dust storm that lasts more than one month, a large number of dust rises into the atmosphere of Mars.