For a long time it was believed that our blue planet is the only place in solar system where there are conditions for the existence of life forms. In reality, it turns out that the near space is not so lifeless anymore. Today we can safely say that within the reach of earthlings there are worlds in many respects similar to our home planet. This is evidenced by interesting facts obtained as a result of studies of the vicinity of the gas giants Jupiter and Saturn. Of course, there are no rivers and lakes with clear and clean water, and grass does not grow green on the endless plains, but under certain conditions, humanity could take up their development. One such object in the solar system is Titan, the largest moon of Saturn.

Representation of the largest satellite of Saturn

Titan today worries and occupies the minds of the astronomical community, although more recently this heavenly body, as well as other similar objects of the solar system, we looked without much enthusiasm. It was only thanks to the flights of interplanetary space probes that it was discovered that liquid matter exists on this celestial body. It turns out that not far from us there is a world with seas and oceans, with a solid surface, shrouded in a dense atmosphere, very similar in structure to the earth's air shell. The size of Saturn's moon is also impressive. Its diameter is 5152 km, at 273 km. more than Mercury, the first planet in the solar system.

Previously, it was believed that the diameter of Titan is 5550 km. More accurate data on the size of the satellite have already been obtained in our time, thanks to the flights of the Voyager 1 spacecraft and the mission of the Cassini-Huygens probe. The first apparatus was able to detect a dense atmosphere on the satellite, and the Cassini expedition made it possible to measure the thickness of the air-gas shell, which is more than 400 km.

The mass of Titan is 1.3452 10²³ kg. According to this indicator, it is inferior to Mercury, as well as in density. The distant celestial body has a low density - only 1.8798 g / cm³. These data speak in favor of the fact that the structure of the satellite of Saturn differs significantly from the structure of the planets. terrestrial group, which are much more massive and heavier. In the Saturn system, this is the largest celestial body, the mass of which is 95% of the mass of the other 61 known moons of the gas giant.

Luckily and the location of the largest Titan. It runs in an orbit with a radius of 1,221,870 km at a speed of 5.57 km / s and stays outside the rings of Saturn. The orbit of this celestial body has an almost circular shape and is in the same plane as Saturn's equator. The orbital period of Titan around the parent planet is almost 16 days. Moreover, in this aspect, Titan is identical with our Moon, which rotates around its own axis synchronously with its owner. The satellite is always turned to the parent planet on one side. The orbital characteristics of the largest moon of Saturn ensure the change of seasons on it, however, due to the considerable distance of this system from the Sun, the seasons on Titan are quite long. The last summer season on Titan ended in 2009.

It is similar in size and mass to the other two largest moons in the solar system, Ganymede and Callisto. Such large sizes testify to the planetary theory of the origin of these celestial bodies. This is confirmed by the surface of the satellite, on which there are traces of active volcanic activity, which is characteristic feature terrestrial planets.

For the first time, a photo of the surface of the satellite of Saturn was obtained using the Huygens probe, which safely landed on the surface of this celestial object on January 14, 2005. Already a cursory glance at the pictures gave every reason to believe that a new mysterious world living his space life. This is not the Moon, lifeless and deserted. This is the world of volcanoes and methane lakes. It is assumed that there is a vast ocean below the surface, possibly consisting of liquid ammonia or water.

Landing of the Huygens

The history of the discovery of Titan

For the first time, the existence of the satellites of Saturn was guessed by Galileo. Not having the technical ability to observe such distant objects, Galileo predicted their existence. Only Huygens, who already had a powerful telescope capable of magnifying objects 50 times, began to explore Saturn. It was he who managed to detect such a large celestial body revolving around a ringed gas giant. This event took place in 1655.

However, the name of the new celestial body had to wait. Initially, scientists agreed to give the discovered celestial body a name in honor of its discoverer. After the Italian Cassini discovered other satellites of the gas giant, they agreed to number the new celestial bodies of the Saturn system.

This idea was not continued, since other objects in the vicinity of Saturn were subsequently discovered.

The notation we use today was proposed by the Englishman John Herschel. They agreed that the largest satellites should have mythological names. Due to its size, Titan was the first on this list. The remaining seven large satellites of Saturn received names consonant with the names of the titans.

Atmosphere of Titan and its features

Among the celestial bodies of the solar system, Titan has perhaps the most curious air shell. The atmosphere of the satellite turned out to be in fact a dense layer of clouds, which for a long time prevented visual access to the very surface of the celestial body. The density of the air-gas layer is so high that near the surface of Titan Atmosphere pressure 1.6 times higher than terrestrial parameters. Compared to the Earth's air shell, the atmosphere on Titan has a significant thickness.

The main component of the titanium atmosphere is nitrogen, the share of which is 98.4%. Approximately 1.6% are argon and methane, which are mainly located in the upper layers of the air shell. With the help of space probes, other gaseous compounds were also found in the atmosphere:

• acetylene;
• methylacetylene;
• diacetylene;
• ethane;
• propane;
• carbon dioxide.

Small amounts of cyan, helium and carbon monoxide. No free oxygen has been found in Titan's atmosphere.

Despite such a high density of the air-gas envelope of the satellite, the absence of a strong magnetic field affects the state of the surface layers of the atmosphere. The upper atmosphere is exposed to the solar wind and cosmic radiation. Nitrogen (N) under the influence of these factors reacts, forming a number of curious nitrogen-containing compounds. Most of some of the compounds are deposited on the surface of the satellite, giving it a slightly orange tint. The history of methane is also interesting. Its composition in Titan's atmosphere is stable, although due to external influences, this light gas could have evaporated long ago.

Looking at the satellite's atmosphere in layers, one can notice a curious detail. The air shell on Titan is stretched in height and is clearly divided into two layers - near-surface and high-altitude. The troposphere begins at an altitude of 35 km. and ends with the tropopause at altitudes of 50 km. Here there are consistently low temperatures of -170⁰ C. Further, with altitude, the temperature drops to -120 degrees Celsius. Titan's ionosphere begins at an altitude of 1000-1200 km.

It is assumed that this composition of the atmosphere of Titan is due to its active volcanic past. Vaporized ammonia, the air layers under the influence of cosmic ultraviolet decomposed into nitrogen and hydrogen, and other components are the result of physical and chemical reactions. As heavier, nitrogen sank and became the main component of the titanium atmosphere. Hydrogen, due to the weak gravitational forces of the satellite, escaped into outer space.

The layers of Titan's atmosphere, the interaction of its chemical composition with the magnetic field of a celestial body contribute to the fact that the satellite has its own climate. The seasons on Titan change like Earth's seasons. At a time when one side of the satellite is facing the Sun, Titan is plunging into summer. Storms and hurricanes rage in its atmosphere. The air layers heated by sunlight are in constant convection, generating strong winds and significant movements of cloud masses. At altitudes of 30 km, the wind speed reaches 30 m/s. The higher, the more intense and powerful the turbulence of air masses. Unlike Earth, the cloud masses on Titan are concentrated in the polar regions.

The concentration of methane in the upper atmosphere explains the increase in temperature on the surface of the satellite due to the greenhouse effect. However, the presence of air masses organic molecules allows ultraviolet to freely penetrate in both directions, cooling the surface layer of the titanium crust. The surface temperature is -180⁰С. The difference between the temperatures at the poles and at the equator is negligible - only 3 degrees.

High pressure and low temperatures contribute to the fact that water molecules in the atmosphere of the satellite completely evaporate (freeze).

The structure of the satellite: from the outer shell to the core

The assumption and conjectures about the structure of such a large celestial body were mainly based on the data of terrestrial optical observations. The dense atmosphere of Titan inclined scientists towards the hypothesis of the gas composition of the satellite, akin to the composition of the mother planet. However, after the flights of the Pioneer 11 and Voyager 2 space probes, it became clear that we are dealing with a celestial body whose structure is solid and stable.

Today, Titan is believed to have a crust similar to Earth's. The diameter of the core is approximately 3400 km, which is more than half the diameter of the celestial body. Between the core and the crust there is an ice layer, which differs in its composition. Probably, at certain depths, the ice transforms into a liquid structure. A comparison of images taken from the Cassini AMS with a difference of two years indicated the presence of a displacement of the satellite's surface layer. This information gave scientists a reason to believe that the surface of the satellite rests on a liquid layer, which consists of water and dissolved ammonia. The displacement of the crust is caused by the interaction gravitational forces and atmospheric circulation.

In its composition, Titan is a combination of ice and silicate rocks in equal proportions, which is very similar to the internal structure of Ganymede and Triton. However, due to the presence of a dense air shell, the structure of the satellite has its own differences and specifics.

The main features of a distant satellite

The mere presence of an atmosphere on Titan makes it unique and interesting for further study. Another thing is that the main highlight of the distant satellite of Saturn is the presence of large volumes of liquid on it. This failed planet is characterized by lakes and seas, in which waves of methane and ethane splash instead of water. The satellite has clusters on the surface space ice, which owes its origin to water and ammonia.

Evidence of the existence of liquid matter on the surface of Titan came from photographs of a huge basin larger than the Caspian Sea in area. The huge sea of ​​liquid hydrocarbons is called the Kraken Sea. According to its composition, it is a huge natural reservoir of liquefied gases: ethane, propane and methane. Another large accumulation of fluid on Titan is the Ligeia Sea. Most of the lakes are concentrated in the northern hemisphere of Titan, which greatly increases the reflectivity of a distant celestial body. After the Cassini mission, it became clear that the surface is 30-40% covered with liquid matter collected in natural seas and lakes.

Such great amount methane and ethane, which are in a frozen state, contributes to the development of certain forms of life. No, these will not be habitual terrestrial organisms, however, under such conditions, living organisms on Titan can take place. The satellite has enough components and chemical substances for the formation of organisms and their subsequent existence.

Timeline of modern Titan exploration

It all started with the modest mission of the American Pioneer 11 probe, which in 1979 managed to give scientists the first pictures of a distant satellite. For a long time, the information received from the Pioneer was of little interest to astrophysicists. Progress in studying the vicinity of Saturn came after Voyager visits to this region of the solar system, which gave more detailed images of the satellite, taken from a distance of 5000 km. Scientists have received more accurate data on the size of this giant, the version about the existence of a dense atmosphere of the satellite has been confirmed.

Flight of the Pioneer

Infrared images taken from the Hubble Space Telescope have provided scientists with information about the composition of the moon's atmosphere. For the first time, light and dark regions were identified on the planetary disk, the nature of which remained unknown. For the first time, a theory was born that the surface of Titan is covered in some places with ice, which increases the reflectivity of the celestial body.

Success in the field of research came along with information received from the Cassini automatic interplanetary station. Launched in 1997, the Cassini mission is common development ESA at NASA. Saturn became the main focus of research, but its satellites were not left without attention. So, to study Titan, the flight program included the stage of landing on the surface of Saturn's satellite of the Huygens probe. This device, created by the efforts of NASA and the Italian space agency, whose team decided to celebrate the anniversary of their glorious compatriot Giovanni Cassini, was supposed to descend to the surface of Titan.

Cassini orbiting Saturn

For 4 years, Cassini continued to work in the vicinity of Saturn. During this time, AMS flew twenty times near Titan, constantly receiving new data about the satellite and its behavior. Already one landing of the Huygens probe on Titan, which took place on March 14, 2007, is considered a tremendous success for the entire mission. Despite this, given the technical capabilities of the Cassini station and its great potential, it was decided to continue research on Saturn and its satellites until 2017.

The flight of Cassini and the landing of the Huygens spacecraft provided scientists with comprehensive information about what Titan really is. Photographs and video filming of the surface of Saturn's moon have shown that the upper layers of the crust are a mixture of mud and gaseous ice. The main fragments of the soil are stones and pebbles. Titan's landscape is an alternation of solid, elevated areas with lowlands. During the landing, pictures of the landscape were taken, which clearly marked the riverbeds and coastline.

Photo of Titan from the Huygens

Titan today and tomorrow

How the further study of the largest satellite will end is unknown. It is assumed that the conditions created in terrestrial laboratories, similar to those that exist on Titan, will shed light on the version of the possibility of the existence of life forms. Flights of space probes into this region of space are not yet planned. The information obtained is sufficient to model Titan under terrestrial conditions. How useful these studies will be, only time will tell. It remains only to wait and hope that Titan will reveal its secrets in the future, giving hope for its development.

Let's start with the rain. It has been found that the clouds on Titan are composed of organic compounds- hydrocarbonates, represented mainly by methane and, to a lesser extent, ethane. Small amounts of propane, ammonia**, acetylene, and also water ice. Clouds are sources of methane and ethane rain**. The largest number clouds are concentrated in the northern and southern polar regions of Titan. In the north, this is generally a zone of continuous cloudiness, which covers Titan with a "blanket" up to 62 ° C.L.

In addition, scientists have obtained evidence of the existence of "underground" reservoirs of methane, ethane and propane, which find their way to the surface in the form of geysers and feed the rivers. The rivers and seas on Titan also consist ofmethane and ethane.
Thus, the circulation of substances constantly takes place on Titan: the eruption of gas and liquid from the bowels, the precipitation in the form of rain or snow, the deposition of matter and evaporation. This process is similar to that which takes place on Earth, only on our planet water is involved in the cycle, and on Titan - hydrocarbons. Truth, Water has also been found on Titan, and in large quantities. - in the form of deposits of water ice and flows of the so-called "cryovolcanic" superheated ice or a mixture liquid water and ammonia. According to scientists from the University of Arizona and the University of Nantes, under the surface of Titan there may be an ocean of liquid water with ammonia dissolved in it.
E Another feature of the surface of Titan, bringing it closer to the Earth, are extended lines and linear zones that delimit areas with different type relief, which often intersect with each other.
According to experts, they are faults in the crust of this planet, which consists of a mixture of water and hydrocarbonate ice. In addition, a structure was found on the surface of Titan that is very similar to a volcano with a diameter of 30 km with lava flows flowing down from it - ice or a mixture of liquid water and ammonia, a volcanic caldera with a diameter of 180 km, volcanic calderas20-30 km in diameter and lava flows from ice or a mixture of liquid water and ammonia over 200 km long.
Thus the Titanit is an active planet in all respects , which is characterized by:
- circulation of the atmosphere, manifested in the formation and transport of clouds, precipitation (rain and possibly snow) and weather changes;
- endogenous (deep) activity, manifested in the formation of faults and cryolitic volcanism,
- exogenous (surface) activity, manifested in the weathering of rocks and the deposition of sediments.
At present, the three listed types of activity have been observed simultaneously only on Earth and Titan.

As on other planets of the solar system, several (certainly two - Xa and Sinlap) meteorite craters with a diameter of 40 to 80 km and one giant ring structure with a diameter of about 450 km, called the circus Maximum or Mernvoy, were found on Titan. It, apparently, is an ancient meteorite crater - a water basin limited by ring-shaped mountain ranges, which was formed during a collision with Titan of an asteroid or comet tens of kilometers in size. A small number of meteorite craters encountered on the surface of Titan testify to the young age of its surface, which continues to form at the present time.

Are Titans inhabited?

At first glance, it may seem that temperatures below -180 ° C prevailing on the surface of Titan do not even allow one to think about life on this planet. But this is in the opinion of earthlings, accustomed to living in more comfortable, from their point of view, conditions. "No, life is impossible in this cold," 99.9% of us would probably say.
But is it? After all, nothing happens by chance in nature. In any habitable world, rains are likely to water the land and fill the rivers; rivers, lakes and seas - serve as a source of fluid and habitat for organisms leading a marine lifestyle. Plains and mountains should be the habitat of various land organisms.
It is known that all living things on Earth are mainly composed of water. Water content in different organisms ranges from 50-75% (terrestrial plants), 60-65% (terrestrial vertebrates), 80-99% (fish and marine animals and plants). But what if the inhabitants of Titan, if they, of course, exist, are also 50 or 99% liquid methane or ethane, and the remaining 50 or 1% of some material that can withstand such low temperatures? Whether they in this case have a solid skeleton, for example, made of silicon, or whether they are gel-like creatures like jellyfish (by the way, jellyfish on Earth use nitrogen as food) is unknown. Howbeit, organic matter more than enough to build organisms and food for them on Titan. This means that the prerequisites for the development of life exist. But what about life itself?
One thing is clear: if there is life on Titan, it is undoubtedly other life that will be difficult to contact.

I express my sincere gratitude to NASA (NASA) and ECA (ECA) for the opportunity to use the photos

The hypothesis about the possibility of the existence of life on Titan is confirmed in the works of many scientists. Christopher McKay of NASA Ames Research Center, Heather Smitha of the International Space University in Strasbourg, Dirk Schulze-Makuha of Washington state university, David Grinspun from the Denver Museum of Nature and some other researchers believe that such a large content of methane in the atmosphere of Titan is not accidental. In fact, the sun's rays reaching the surface of the planet must destroy methane molecules, and without its constant replenishment, all atmospheric methane available on Titan would have to be destroyed in 10-20 million years. Suggested sources of this gas may be the volcanic activity occurring on Titan and the life that exists there. The possibility of the existence of life on Titan seems to be confirmed by a decrease in the content of hydrogen in the lower part of its atmosphere. According to Christopher McKay, this is due to the fact that it is consumed by living organisms.

Almost 5 years after this article was written, new data have been obtained that convincingly prove the existence of life on Titan. Read about it in the news

Read also my new job"Life on Titan. What is she?"

I invite everyone to further discussion this material on the pages

Titan is the largest moon of Saturn and the second, after Ganymede, in the solar system. However, if you measure Titan along with its atmosphere, then it turns out to be larger than Ganymede. In all its parameters, Titan is closest to normal planets: it is larger than Mercury, its dense atmosphere is thicker than that of the Earth, and the surface - in a geographical sense - is almost as alive as that of our planet.

Ground observations before the start space age showed that Titan has a dense atmosphere; in fact, it is the only satellite planet with a full atmosphere. Flying in 1981 through the Saturn system, Voyager 2 discovered that the main component of Titan's atmosphere is nitrogen (N 2); it also contains methane (CH 4 ) and other hydrocarbons. Data from the Hubble Space Telescope and ground-based telescopes made it possible in 1995 to suspect the existence of large areas covered with liquid methane on the surface of Titan. But the existence of these hydrocarbon lakes was confirmed only after the first artificial satellite Saturn - Cassini, from which, on January 14, 2005, the Huygens probe landed on the surface of Titan. The Cassini-Huygens expedition, organized by NASA, ESA (European Space Agency) and ASI (Italian Space Agency), began on October 15, 1997, but only in the middle of 2004 did the device arrive in the Saturn system and start working (see. page 16 of the color tab).

Titan is almost twice as massive as the Moon and half as large as it. Therefore, on its surface, gravity is almost lunar: it is 7 times less than the earth (on the Moon - 6 times). Second space velocity on the surface of Titan - 2.6 km / s, on the Moon - 2.4 km / s, however, taking off from Titan will be much more difficult than from the Moon: a dense atmosphere will interfere. The composition of Titan's atmosphere is now known in detail: at the surface 95% nitrogen and about 5% methane, and in the stratosphere 98.4% nitrogen and 1.4% methane. The pressure near the surface is 1.45 times the normal atmospheric pressure on Earth. But if we remember that the force of gravity there is 7 times less than ours, then it is clear that the mass of the gas column over a unit surface of Titan is 10 times greater than on Earth. Since the size of Titan is 2.5 times smaller than the Earth's, its surface area is approximately 6 times smaller than the Earth's, which means that the total mass of Titan's atmosphere is 1.5 times the mass earth's atmosphere! This is probably why there are very few meteorite craters on the surface of Titan: small meteorites are decelerated and destroyed in the atmosphere, and traces of large ones are quickly destroyed by rain and wind.

The powerful and extremely extended atmosphere of Titan made it easier for spacecraft to land on it. Separated from Cassini, the Huygens probe moved dormantly towards Titan for three weeks, and then began to prepare for descent. Landing the Huygens on Titan is a unique operation; here are its main stages (hours:minutes CET):

06:51 - the power supply of the devices is turned on.

11:13 - beginning of entry into the atmosphere at an altitude of 1270 km at a speed of 6 km/s. Braking is carried out by a frontal heat shield.

11:17 - height 180 km, speed 400 m / s, pilot chute with a diameter of 3 m is deployed. After 2.5 seconds, it pulls the main parachute with a diameter of 8.3 m.

11:18 - height 160 km. The front screen has been removed. A gas chromatograph and a mass spectrometer began to investigate the atmosphere. Aerosols are collected and evaporated. The camera transmits a panorama of clouds.

11:32 - height 125 km. The main parachute was dropped and a braking parachute with a diameter of 3 m was deployed in order to accelerate the fall and have time to land before the batteries were completely discharged (charge 1.8 kWh). The distance to Cassini is 60,000 km.

11:49 - height 60 km. Radar altimeter included; before that, the timer controlled the work. The camera starts capturing a panorama of the surface. The wind speed is measured (according to the Doppler effect of the transmitter), air temperature and pressure, electric field (the presence of lightning is checked). At a height of several hundred meters from the surface, a white lamp was turned on for spectral analysis of the surface. Sonar and radar measure ground irregularities. The descent of Huygens in the atmosphere of Titan took about 2.5 hours.

13:34 - touching the ground at a speed of 4.5 m / s. The camera, microphone, accelerometers and sonar are working to measure the depth of the liquid if the landing took place at sea. But the soil under the apparatus turned out to be reliable, in terms of mechanical properties similar to wet sand or clay. The device, upon impact, went deep into the ground by about 15 cm. Within 2 hours, it transmitted data from the surface at a speed of 8 kbit / s.

15:44 - Cassini goes below the horizon End of data transmission. Cassini turns its antenna towards the Earth and begins broadcasting data recorded from Huygens.

The probe landed a little south of the equator, on the edge of the ice hills in the middle of a huge sandy sea. A photo of the surrounding landscape shows a couple of long dunes in the distance, but the landing site itself looks more like a stream bed littered with cobblestones on top of the sand. The temperature at the surface of Titan is very low: -180°C. This temperature is close to the triple point of methane, just as the temperature of the earth's surface is close to the triple point of water. At this temperature, gas, liquid and solid states of matter coexist. Just as the water cycle occurs in the nature of the Earth, the methane cycle must occur on Titan. In fact, methane (mixed with ethane and other hydrocarbons) plays the same role there as water on Earth: it evaporates from lakes, forms clouds, falls as precipitation, makes channels through valleys and flows back into lakes.

A study of the images shows that Titan's landscape is partly shaped by showers and the rapid flow of liquid across the surface. But, unlike Earth, this hydrological cycle on Titan is brought to an extreme state. On Earth, solar heat is enough to evaporate about one meter of water per year. But the atmosphere can only hold a couple of centimeters of sedimented moisture before clouds condense and rain falls, so Earth weather is characterized by light rains pouring a few centimeters of water at intervals of a week or two. On Titan, the lack of solar heat leads to the evaporation of only about 1 cm of liquid methane per year, and its powerful atmosphere is able to keep in gaseous form the amount of methane corresponding to about 10 m of the precipitated liquid. Therefore, Titan should be characterized by rare heavy rains, giving rise to turbulent streams, and in the intervals between these floods, secular periods of drought. It is likely that there was also a flood at the landing site of the Huygens some time ago. Climate scientists believe Titan's powerful weather cycles are an extreme version of what could happen on Earth as a result of global warming. As the Earth's troposphere warms, it will be able to hold more and more moisture, so hurricanes and droughts will become more intense for us.

So, Titan is a frozen version of Earth, where methane is instead of water, water is instead of rock, and weather cycles last for centuries. It is very likely that the atmosphere of Titan resembles the atmosphere of a young Earth during the birth of life on it. Moreover, the average density of Titan (1.88 g/cm³) indicates that it is half rock (core), half water (mantle and crust) and covered with hydrocarbons. Mathematical models predict that the ice crust is about 50 km thick, with an ocean of liquid water below, possibly with ammonia. The depth of this "ammonia" ocean should reach hundreds of kilometers. Some scientists believe that there may be life there.

It is planned that the operation of the Cassini apparatus will continue until 2017. From July 2004 to September 2010, it made 72 flybys near Titan, transmitting radar images of its surface and images in the infrared range. When researchers became interested in the source of smog in Titan's atmosphere, Cassini, flying through the upper layers of its atmosphere, at an altitude of about 1000 km, collected and analyzed samples of this fog. Scientists expected the fog to be made up of light hydrocarbons such as ethane with a molecular weight of 30. But Cassini found an unexpected abundance of heavy organic molecules, including benzene, anthracene, and macromolecules with masses of 2,000 or more. These substances are formed from atmospheric methane under the action of sunlight. They probably gradually condense into larger particles and sink to the surface, but the details of this process are not clear.

As you can see, the wonderful little planet Titan is getting more and more interesting. Fundamental difficulties in the study of Titan are not expected. For expeditions to it, "titan rovers" are already being developed, as well as floating and flying probes. A fun activity for space engineers!

For that category of enthusiastic scientists who are interested in the existence of extraterrestrial worlds suitable for exploration, the well-known phrase: “Is there life on Mars, is there life on Mars”, has ceased to be relevant today. It turned out that within the solar system there are worlds that are much more interesting in this aspect than the Red Planet. A striking example of this is the largest satellite of Saturn, Titan. It turned out that this celestial body is very similar to our planet. The information that scientists have today admits the existence of a scientific version that life on Titan, a satellite of Saturn, is a very real fact.

Why is Titan so interesting for earthlings?

After decades of trying unsuccessfully to find a world within our solar system that even remotely resembled our Earth, information about Titan gave hope to the scientific community. Closely this celestial body, scientists have become interested since 2005, when the automatic probe "Huygens" landed on the surface of one of the largest satellites of the solar system. Over the next 72 minutes, the onboard photo and video camera of the spacecraft transmitted to Earth a photo of the surface of this object and other video materials about this distant world. Even in such a limited time allotted for instrumental studies of a distant satellite, scientists were able to obtain an exhaustive amount of information.

Landing on the surface of Titan was carried out as part of international program"Cassini-Huygens", aimed at studying Saturn and its satellites. Launched back in 1997, the Cassini robotic interplanetary station is a joint development of ESA and NASA for a detailed study of Saturn and the surrounding area of ​​\u200b\u200bthis planet. After 7 years of flight through the expanses of the solar system, the station delivered to Titan space probe"Huygens". This unique spacecraft is the result of a joint effort between NASA and the Italian space agency, whose team had high hopes for this flight.

The results that scientists received from the operating Cassini station and from the Huygens probe turned out to be invaluable. Despite the fact that a distant satellite appeared before the gaze of earthlings as a huge silent realm of ice, the subsequent detailed study of the surface of the object changed the idea of ​​​​Titan. In the pictures taken with the help of the Huygens probe, it was possible to make out in great detail the surface of the satellite of Saturn, which mainly consisted of solid water ice and sedimentary layers of an organic nature. It turned out that the dense and impenetrable atmosphere of a distant satellite has almost the same composition as the earth's air-gas shell.

In the future, Titan threw scientists another serious bonus. For the first time in the history of the development and study of extraterrestrial space outside the Earth, liquid matter of the same nature was found that was on the planet Earth in the early years of its existence. The relief of the celestial body is complemented by a huge ocean, numerous lakes and seas. All this gives reason to believe that we are dealing with a celestial body, which could be another oasis of life in our solar system. Studies of the composition of the atmosphere and liquid medium of the satellite of Saturn revealed the presence of useful substances necessary for the life of organisms. It is assumed that under certain conditions in the process of studying this celestial body, living organisms can be found on Titan.

In this regard, the subsequent study of the largest satellite of Saturn becomes relevant. It is highly likely that, along with Mars, it is Titan that can become the second space home for human civilization.

Academic view of Titan

The size of Titan allows it to compete with the planets of the solar system. This celestial body has a diameter of 5152 km, which is greater than the diameter of Mercury (4879 km) and slightly smaller than Mars (6779 km). The mass of Titan is 1.3452 1023 kg, which is 45 times less than the mass of our planet. By its mass, the satellite of Saturn is the second in the solar system, yielding to the satellite of Jupiter - Ganymede.

Despite its impressive size and weight, Titanium has a low density, only 1.8798 g/cm³. For comparison, the density of the parent planet Saturn is only 687 c/m3. Scientists have identified a weak gravitational field in the satellite. The force of attraction on the surface of Titan is 7 times weaker than the earth's parameters, and the acceleration of free fall is the same as on the Moon - 1.88 m/s2 versus 1.62 m/s2.

A characteristic feature is the position of Titan in space. The largest satellite of Saturn revolves around its parent planet in an elliptical orbit at a speed of 5.5 km / s, being outside the region of Saturn's rings. The average distance from Titan to the surface of Saturn is 1.222 million km. This entire system is located at a distance of 1 billion 427 million km from the Sun, which is 9.5 times the distance between our central star and the Earth.

Like our satellite, the “Moon of Saturn” is always turned to it with one side. This is due to the synchronism of the satellite's rotation around its own axis with the period of Titan's revolution around the parent planet. Its largest satellite makes a complete revolution around Saturn in 15 Earth days. Due to the fact that Saturn and its satellites have a fairly high angle of inclination of the axis of rotation to the axis of the ecliptic, there are seasons on the surface of Titan. Every 7.5 Earth years on the satellite of Saturn, summer is replaced by a cold winter period. According to astronomical observations, autumn is on the side of Titan that faces Saturn today. Soon the satellite will hide from the sun's rays behind the mother planet and the Titanic autumn will be replaced by a long and fierce winter.

Temperatures on the surface of the satellite vary between minus 140-180 degrees Celsius. Data obtained from the Huygens space probe revealed a curious fact. The difference between polar and equatorial temperatures is only 3 degrees. This is explained by the presence of a dense atmosphere, which prevents the impact of sunlight on the surface of Titan. Despite the high density of the atmosphere, there is no liquid precipitation on Titan due to low temperatures. In winter, the surface of the satellite is covered with snow from ethane, particles of water vapor and ammonia. This is only a small part of what we know about Titan. Interesting Facts about the largest satellite of Saturn concern literally any field, from astronomy, climatology and glaciology to microbiology.

Titan in all its glory

Until recently, most of the information about Saturn's moon was based on visual observations obtained from the Voyager space probe, which raced past it at a distance of 7000 km in 1980. The Hubble telescope slightly opened the veil of secrecy about this space object. To get an idea of ​​the surface of the satellite did not allow its dense atmosphere, which in density and thickness is second only to the Venusian and terrestrial air-gas shell.

The mission of the Cassini automatic station in 2004 helped to remove the veil of fog that reigned over this celestial body. For four years, the device was in orbit of Saturn, carrying out sequential photography of its satellites, including Titan. Research from the Cassini probe was carried out using a camera with an infrared filter and a special radar. The photographs were taken from different angles at a distance of 900-2000 km from the satellite surface.

The culmination of the study of Titan was the landing on its surface of the Huygens probe, named after the discoverer of Saturn's moon. The apparatus, having entered the dense layers of the atmosphere of Titan, descended by parachute for 2.5 hours. During this time, the probe equipment studied the composition of the satellite's atmosphere, photographed its surface from a height of 150, 70, 30, 15 and 10 kilometers. After a long descent, the space probe landed on the surface of Titan, burrowing 0.2-0.5 meters into the dirty ice. After landing on the moon, Huygens worked for a little more than an hour, transmitting mass to Earth through the Cassini AMS. useful information directly from the surface of the satellite. Thanks to images taken from the Cassini spacecraft and the Huygens probe, a team of researchers has compiled a map of Titan. In addition, scientists now had detailed information about its atmosphere, data on the climate on the surface and features of the relief.

satellite atmosphere

In the situation with Titan, for the first time in the process of studying and studying the celestial bodies of the solar system, scientists had the opportunity to study the atmosphere in detail. As expected, the satellite of Saturn has a dense and well-developed atmosphere, which not only resembles the gaseous shell of the Earth in many respects, but also surpasses it in mass.

The thickness of the atmospheric layer of Titan was 400 km. Each layer of the atmosphere has its own composition and concentration. The gas composition is as follows:

• 98.6% leaves nitrogen N;
• 1.6% in the atmosphere is methane;
• a small amount of ethane, acetylene compounds, propane, carbon dioxide and carbon monoxide, helium and cyan.

The concentration of methane in the atmosphere of the satellite, starting from a height of 30 km, changes in the direction of decrease. As you approach the surface of the satellite, the amount of methane decreases to 95%, but the concentration of ethane increases to 4-4.5%.

A characteristic feature of the air-gas layer of the Titan satellite is its anti-greenhouse effect. The presence of hydrocarbon organic molecules in the lower layers of the atmosphere neutralizes the greenhouse effect created by a huge concentration of methane. As a result, the surface of the celestial body cools evenly due to the presence of hydrocarbons. The same processes and the gravitational field of Saturn determine the circulation of the atmosphere of Titan. Such a picture contributes to the formation of active climatic processes in the atmosphere of Saturn's moon.

It should be noted that the atmosphere of the satellite is constantly losing weight. This is due to the absence of a powerful magnetic field in the celestial body, which is not able to hold the air-gas shell, which is under the constant influence of the solar wind and the gravitational forces of Saturn. To date, the atmospheric pressure on the satellite of the ringed giant is 1.5 atm. This is invariably reflected in weather conditions, which change with the concentration of gases in Titan's atmosphere.

The main work on creating weather on Titan is performed by dense clouds, which, unlike terrestrial air masses, consist of organic compounds. It is these atmospheric formations that are the source of precipitation on the largest satellite of Saturn. Due to low temperatures, the atmosphere of the celestial body is dry. The highest concentration of cloudiness was found in the polar regions. Due to low temperatures, the humidity in the atmosphere is extremely low, so the precipitation on Titan is methane ice crystals and frost, consisting of compounds of nitrogen, ethane and ammonia.

The surface of Titan and its structure

Saturn's satellite has not only an interesting atmosphere. Its surface is an extremely curious object from the point of view of geology. Under a thick blanket of methane, the photographic lenses and cameras of the Huygens space probe discovered entire continents, separated by numerous lakes and seas. As on Earth, there are plenty of rocky and mountain formations on the continents, there are deep crevices and depressions. They are replaced by vast plains and valleys. In the equatorial part of the celestial body, a vast area of ​​dunes was formed by particles of hydrocarbonate and water ice. It is assumed that the Huygens space probe landed on one of these dunes.

The complete resemblance to a living planet adds the presence of a liquid structure. On Titan, rivers have been discovered that have sources, winding channels and deltas - places where streams flow into sea basins. According to the data taken from the images, some of the rivers of Titan have a channel length of more than 1000 km. Almost all of the liquid mass of Titan is concentrated in sea basins and lakes, which occupy an impressive area - up to 30-40% of the entire surface area of ​​this celestial body.

Evidence of the presence of large accumulations of liquid medium on the surface of the satellite was a huge bright spot, which for a long time confused astronomers. Subsequently, it was proved that the bright region on Titan is a huge pool of liquid hydrocarbons, called the Kraken Sea. By area, this imaginary body of water is larger than the largest lake on Earth - the Caspian Sea. Another equally interesting object is the Ligeia Sea - the largest natural reservoir for liquid methane and ethane.

Accurate information about the composition of the liquid environment of the seas and lakes of Titan was obtained thanks to the work of the Casssini AMS. Using data from photographs and computer simulations, the composition of the liquid on Titan was determined under terrestrial conditions:

• ethane is 76-80%;
• propane in the seas and lakes of Titan 6-7%;
• methane accounts for 5-10%.

In addition to the main elements, presented in the form of frozen gases, hydrogen cyanide, butane, butene and acetylene are present in the liquid. The main accumulation of water on Titan has a nature somewhat different from the earth's form. Huge deposits of superheated ice, consisting of water and ammonia, were found on the surface of the satellite. It is assumed that under the surface there may be extensive natural reservoirs filled with liquid water with ammonia dissolved in it. In this aspect, the internal structure of the satellite is also interesting.

Today, various versions are being put forward about the internal structure of Titan. As is the case with all the planets of the terrestrial group, it has a solid core, not iron-nickel, as on the first four planets of the solar system, but stone. Its diameter is approximately 3400-3500 km. Then the most interesting begins. Unlike the Earth, where the mantle begins after the core, on Titan this space is filled with dense compressed layers of water ice and methane hydrate. Probably, there is a liquid layer between the individual layers. However, despite its coldness and stone nature, the satellite is in an active phase and tectonic processes are observed on it. This is facilitated by tidal forces, which are caused by the giant gravity of Saturn.

Possible future of Titan

According to research conducted in last decade, humanity is dealing with a unique object in the solar system. It turned out that Titan is the only celestial body, in addition to the Earth, which is characterized by all three types of activity. On the satellite of Saturn, traces of constant geological activity are observed, which are confirmation of its living tectonic activity.

To a large extent, the nature of the surface of Titan is also interesting. Its structure, composition and relief speak in favor of the fact that the surface of Saturn's moon is in constant motion. Here, as on Earth, under the influence of winds and precipitation, soil erosion is observed, rocks are weathered and sediments are deposited.

The composition of the satellite's atmosphere and the circulation processes occurring in it shaped the climate on Titan. All of these signs speak in favor of the fact that life can exist on Titan under certain conditions. Naturally, it will be a form of life different from terrestrial organisms, but its very existence will be a colossal discovery for mankind.

If you have any questions - leave them in the comments below the article. We or our visitors will be happy to answer them.

Titanium- the largest satellite of Saturn and the second largest solar system: photo, size, mass, atmosphere, name, methane lakes, Cassini research.

The Titans ruled the Earth and became the progenitors of the Olympic gods. That is why the largest satellite of Saturn was named Titan. It occupies the 2nd place in size in the system and exceeds Mercury in volume.

Titan is the only satellite of Saturn endowed with a dense atmospheric layer, which for a long time prevented the study of surface features. Now we have evidence of the presence of liquid on the surface.

Discovery and name of the satellite Titan

In 1655, Christian Huygens noticed a satellite. This discovery was inspired by Galileo's findings near Jupiter. Therefore, in the 1650s. he began to develop his telescope. At first it was simply called the Moon of Saturn. But later, Giovanni Cassini will find 4 more, so he was called by position - Saturn IV.

The modern name came from John Herschel in 1847. In 1907, Josell Comas Sola tracked the darkening of Titan. This is the effect where the center of a planet or star appears much brighter than the edge. This was the first signal to detect the atmosphere on the satellite. In 1944, Gerard Kuiper used a spectroscopic instrument and found a methane atmosphere.

Size, mass and orbit of the Titan satellite

The radius is 2576 km (0.404 Earth), and the mass of the Titan satellite is 1.345 x 10 23 kg (0.0255 Earth). The average distance is 1,221,870 km. But an eccentricity of 0.0288 and an inclination of the orbital plane of 0.378 degrees caused the satellite to approach 1,186,680 km and move away 1,257,060 km. Above is a photo comparing the size of Titan, the Earth and the Moon.

Thus, you learned which planet Titan is a satellite of.

Titan spends 15 days and 22 hours on an orbital flyby. The orbital and axial periods are synchronous, therefore it stays in the gravitational block (turned to the planet by one side).

The composition and surface of the moon Titan

Titanium is denser due to gravitational contraction. Its index of 1.88 g/cm 3 hints at an equal ratio of water ice and rocky material. Inside it is divided into layers with a rocky core covering 3400 km. A 2005 Cassini study hinted at the possible presence of an underground ocean.

It is believed that Titan's liquid consists of water and ammonia, which makes it possible to fix the liquid state even at a temperature mark of -97 ° C.

The surface layer is considered to be relatively young (from 100 million to 1 billion years) and looks smooth with impact craters. The height varies by 150 m, but can reach 1 km. It is believed that this was influenced by geological processes. For example, on the southern side, a mountain range was formed with a length of 150 km, a width of 30 km and a height of 1.5 km. Filled with icy material and a layer of methane snow.

Patera Sotra is a mountain range that rises to a height of 1000-1500 m. Some peaks are endowed with craters and it seems that frozen lava flows have accumulated at the base. If there are active volcanoes on Titan, then they are provoked by energy coming from radioactive decay.

Some believe that before us is a geologically dead place, and the surface was created due to crater impacts, fluid flows and wind erosion. Then methane does not come from volcanoes, but is released from the cold lunar interior.

Among the craters of Titan's moon, the 440-km two-zone Minerva impact basin stands out. It is easy to find by its dark pattern. There are also Sinlap (60 km) and Xa (30 km). Radar survey was able to find crater forms. Among them is the 90-kilometer ring of Guabonito.

Scientists have theorized about the presence of cryovolcanoes, but so far only surface structures with a length of 200 m that look like lava flows have hinted at this.

Channels may hint at tectonic activity, which means that we have young formations in front of us. Or is it an old place. You can find dark areas that are patches of water ice and organic compounds showing up in the UV view.

Methane lakes of the moon Titan

Saturn's moon Titan attracts attention with its hydrocarbon seas, methane lakes and other hydrocarbon compounds. Many of them are noted near the polar regions. One covers an area of ​​15,000 km 2, and a depth of 7 m.

But the largest is the Kraken at the North Pole. The area is 400,000 km 2 and the depth is 160 m. We even managed to note small capillary waves with a height of 1.5 cm and a speed of 0.7 m/s.

There is also the Sea of ​​Ligeia, located closer to north pole. The area covers 126,000 km 2. It was here in 2013 that NASA first noticed mysterious object- Magic island. Later it will disappear, and in 2014 it will reappear in a different form. This is thought to be a seasonal feature created by rising bubbles.

Mostly lakes are concentrated near the poles, but similar formations have also been found on the equatorial line. In general, the analysis shows that the lakes cover only a few percent of the surface, which is why Titan is much drier than our planet Earth.

Titan's atmosphere

Titan is so far the only satellite in the solar system that has a dense atmosphere with a remarkable amount of nitrogen. Moreover, it even exceeds the earth's density with a pressure of 1.469 kPa.

Represented by an opaque haze that blocks incoming sunlight (reminiscent of Venus). Lunar gravity is low, so the atmosphere is much larger than Earth's. The stratosphere is filled with nitrogen (98.4%), methane (1.6%) and hydrogen (0.1%-0.2%).

Titan's atmosphere contains traces of hydrocarbons such as ethane, acetylene, diacetylene, propane, and methylacetylene. It is believed that they form in the upper layers due to the breakdown of methane by UV rays, which creates a thick orange-colored smog.

The surface temperature reaches -179.2°C because, compared to us, the moon receives only 1% of the sun's heat. In this case, the ice is endowed with low pressure. If not for the greenhouse effect from methane, then Titan would be much cooler.

Fog that reflects sunlight works against the greenhouse effect. Simulations have shown that complex organic molecules can appear on the satellite.

Hot planetary coronas

Astronomer Valery Shematovich on the study of gas shells of planets, hot particles in the atmosphere and discoveries on Titan:

The habitability of the Titan satellite

Titanium is perceived as a probiotic medium with a complex organic chemistry and a possible subsurface ocean in a liquid state. Models show that the addition of UV rays in such an environment can lead to the formation complex molecules and substances like tholins. And the addition of energy causes even 5 nucleotide bases.

Many believe that the satellite contains enough organic material to activate the process of chemical evolution similar to that of the Earth. This requires water, but life could survive in the subsurface ocean. That is, life can appear on Saturn's moon Titan.

Such forms must be able to survive in extreme conditions. It all depends on the heat exchange between the inner and upper layers. Do not exclude the presence of life in methane lakes.

To test the hypothesis, several models were created. Atmospheric shows that top layer there is a large volume of molecular hydrogen, which disappears closer to the surface. Low levels acylene also indicate hydrocarbon-consuming organisms.

In 2015, researchers even created a cell membrane capable of functioning in liquid methane under specified lunar conditions. But at NASA, these experiments are considered hypotheses and rely more on the levels of acylene and hydrogen.

In addition, the experiments still concerned earthly ideas about life, and Titan is different. The satellite lives much farther from the Sun, and the atmosphere is devoid of carbon monoxide, which does not allow it to retain the necessary amount of heat.

Exploration of the Titan satellite

The rings of Saturn often overlap the moon, so without special tools, Titan is difficult to find. But then there is a barrier from a dense atmospheric layer, which makes it difficult to see the surface.

For the first time, Pioneer 11 approached Titan in 1979, presenting images. He noted that the moon is too cold to support life forms. Voyagers 1 (1980) and 2 (1981) followed, providing data on density, composition, temperature and mass.

The main information array came from the study of the Cassini-Huygens mission, which arrived at the system in 2004. The probe captured surface details and color patches that were previously inaccessible to human vision. He also noticed the seas and lakes.

In 2005, the Huizens probe descended to the surface, capturing surface formations up close.

He also obtained images of a dark plain that hinted at erosion. The surface was much darker than scientists expected.

IN last years increasingly raise questions about returning to Titan. In 2009, they tried to push the TSSM project, but it was bypassed by EJSM (NASA / ESA), whose probes will go to Ganymede and Europa.

TiME was also planned, but NASA decided that it would be more expedient and cheaper to launch InSight to Mars in 2016.

In 2010, they considered the possibility of launching JET - an astrobiological orbiter. And in 2015, they came to the development of a submarine that can dive into the Kraken Sea. But for now, it's all under discussion.

Titan moon colonization

Of all the satellites, Titan seems to be the most profitable target for a colony.

Titanium has a huge number of elements that are needed to sustain life: methane, nitrogen, water and ammonia. They can be transformed into oxygen and even create an atmosphere. The pressure is 1.5 times higher than the Earth's, and the dense atmosphere protects much better from cosmic rays. Of course, it is filled with flammable substances, but an explosion requires a huge amount of oxygen.

But there is also a problem. Gravity is inferior to the indicators of the earth's moon, which means that the human body will have to fight against muscle atrophy and bone destruction.

It is not easy to cope with frost at -179 ° C. But the satellite is a tasty morsel for explorers. There is a high probability of coming across life forms that can survive in extreme conditions. Perhaps we will also come to colonization, because the satellite will become the starting point for the study of more remote objects and even logout. Below is a map of Titan and high quality photos in high resolution from space.

Titan surface map

Click on the image to enlarge it

Photos of the satellite Titan

The Cassini spacecraft approached within 2 million km on May 29, 2017 to capture the night side of Titan in a photo. This review succeeded in emphasizing the extended atmospheric nebula of the moon. For the entire time of observation, the device managed to fix the satellite from various angles and get a full view of the atmosphere. The high-altitude fog layer is displayed in blue, and the main haze is orange. The difference in color may be based on particle size. Blue, most likely, is represented by small elements. A narrow-angle camera with red, green and blue filters was used for shooting. The scale is 9 km per pixel. The Cassini program is a joint development of ESA, NASA and the Italian Space Agency. The team is based in JPL. The two cameras on board are also made by them. The obtained photos are processed in Boulder (Colorado).

The surface of Titan was observed in detail in the photo during the landing of the Huygens probe. But still, most of the area was displayed by the Cassini apparatus. Titan still remains an interesting riddle. This review shows a new area that was not marked in previous observations. This is a composite image of 4 almost identical wide-angle shots.

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