Amazing titan, satellite of Saturn. The distant satellite Titan: a surprise or another mystery of the solar system Distance from the earth to titan in kilometers

Saturn's satellite Titan is one of the most mysterious and interesting worlds located literally next door to us. In general, our Solar system is so diverse and contains its own worlds so different from each other that the most bizarre conditions and phenomena can be found here. Lava lakes and water volcanoes, seas of methane and almost supersonic hurricanes - all this is literally next door.

Our closest neighbors are much more interesting than people think. And now you will learn about one of them - a satellite named Titan. This is an amazing place, unlike any other.

Titan is a unique place that has no analogues in the solar system.

Titan is the largest satellite of Saturn and the second largest satellite in the Solar System in general after Ganymede, a satellite. It is larger than the Moon and even Mercury, which is an independent planet.
Titan is 80% heavier than the Moon, and in general its mass is 95% of the mass of all satellites of Saturn.
Titan has a very dense atmosphere, which no other satellite, or even every planet, can boast of. For example, Mercury has practically no energy, while Mars has much more rarefied energy. Even the earth’s atmosphere is much inferior in density - the pressure at the surface there is 1.5 times greater than the earth’s, and the thickness of the atmosphere is 10 times greater.
Titan's atmosphere is composed of methane and nitrogen and is completely opaque due to clouds in the upper layers. The surface cannot be seen through it.
On the surface of Titan, rivers flow and there are lakes and even seas. But they do not consist of water, but of liquid methane and ethane. That is, this satellite of Saturn is completely covered with hydrocarbons.
In 2005, the Huygens probe landed on Titan and was delivered there by spacecraft. The probe not only took the first photographs of the surface during its descent, but also transmitted a recording of wind noise.
Titan does not have its own magnetic field.
Titan's sky is yellow-orange.
Winds constantly blow on Titan and hurricanes often occur, especially violent movement occurs in the upper layers of the atmosphere.
Methane rain on Titan.
The surface temperature is about -180 degrees Celsius.
Under the surface of Titan there is an ocean of water laced with ammonia. The surface is predominantly composed of water ice.
Titan has cryovolcanoes that erupt with water and liquid hydrocarbons.
Titan is a promising place to search for extraterrestrial life, at least in the form of bacteria.
Titan is geologically active.

This is the satellite of Saturn - seething, boiling and erupting, where instead of water there are mainly hydrocarbons, although there is also quite enough water. So it is no coincidence that scientists assume that some kind of primitive life can arise there - all the components for this are there, and the conditions are quite comfortable, even if not on the surface itself.

Titan, although not a planet, is the most Earth-like place in the solar system. The atmosphere, rivers, volcanoes, water - all this is there, although in a slightly different quality.

Discovery of Titan

Saturn's moon Titan was discovered on March 25, 1655 by Christiaan Huygens, a Dutch astronomer, mathematician and physicist. He had a homemade 57mm telescope with a magnification of about 50x. Armed with it, Huygens observed the planets, and near Saturn he discovered a certain body that made a complete revolution around the planet in 16 days.

Until June, Huygens observed this strange object, until the rings of Saturn were at their smallest opening and began to interfere with observations. Then the scientist was convinced that it was a satellite of Saturn, and calculated its period of revolution - 16 days and 4 hours. He called it simply – Saturni Luna, that is, “Moon of Saturn.” After Galileo's discovery of the moons of Jupiter, this was the second discovery of a moon around another planet using a telescope.

The satellite received its modern name when John Herschel in 1847 proposed that all the satellites of Saturn be named after the setters and brothers of the god Saturn, and by that time there were seven of them known.

In 1907, Comas Sola, a Spanish astronomer, observed a phenomenon where the central part of its disk becomes brighter than the edges. This served as evidence of the presence of an atmosphere on Titan. In 1944, Gerard Kuiper used a spectrometer to determine that its atmosphere contained methane.

Dimensions and orbit of Titan

The diameter of Titan is 5152 km, that is, 0.4 Earth's. It is the second largest moon in the entire solar system after Ganymede. Before the flight, its diameter was considered 5550 km, that is, larger than Ganymede, and Titan was considered the record holder. However, it turned out that the error arose due to a very thick and opaque atmosphere, and the real size of the satellite itself turned out to be somewhat smaller.

Titan is 50% larger than the Moon and 80% heavier. The gravity on it is 1/7 that of Earth. It consists approximately equally of ice and rock. Callisto and Ganymede have approximately the same structure.

Titan is a fairly large object, so it has a hot core and exhibits geological activity. However, the origin of this satellite is still unclear. The question remains open whether it was captured by Saturn from the outside or immediately formed in orbit from a gas and dust cloud. Since it is very different from the other satellites of Saturn, leaving them all with only 5% mass, the capture theory may well be correct.

The radius of Titan's orbit is 1,221,870 kilometers. It is located far beyond the outermost ring. Thanks to this distance from the planet, this satellite is clearly visible even with a small telescope. It completes a full revolution in 15 days, 22 hours and 41 minutes - Huygens was slightly mistaken in his calculations, although he calculated quite accurately with his simplest means of observation.

Atmosphere of Titan

What is remarkable about Titan is its luxurious atmosphere, which would be the envy of many terrestrial planets, except perhaps Venus. Its thickness is 400 km, which is ten times the Earth’s, and the pressure at the surface is 1.5 Earth’s atmospheres. Mars would definitely be jealous!

This is how Voyager saw Titan

Powerful winds blow in the upper layers, strong hurricanes occur, but only a weak breeze is felt near the surface. The higher you go, the stronger the winds; they coincide with the direction of rotation of the satellite. Above 120 km there is very strong turbulence. But at an altitude of 80 km, complete calm reigns - there is a certain zone of calm, where the wind from the lower regions and storms located above do not penetrate. It is possible that at this altitude, multidirectional air flows compensate and cancel each other out, although the exact nature of this phenomenon has not yet been clarified.

On Titan, it rains or snows from methane or ethane from methane and ethane clouds.

However, the composition of the air there is not at all pleasing - 95% nitrogen, and the rest is mainly methane. By the way, only on Earth and Titan the atmosphere consists mainly of nitrogen! In the upper layers of methane, under the influence of the Sun, the process of photolysis occurs and smog is formed from hydrocarbons, which we see in the form of a dense cloud curtain. This makes it impossible to see the surface of Titan.

The origin of such a vast atmosphere is still unclear, but the most plausible version seems to be the active bombardment of Titan by comets at the dawn of its formation, 4 billion years ago. When a comet collides with a surface rich in ammonia, a large amount of nitrogen is released under the influence of enormous pressure and temperature. Scientists calculated the atmospheric leakage and concluded that the original atmosphere was 30 times heavier than the current one! But even now she is not even frail.

The sky of Titan is approximately the same color as in the picture.

The upper layers of the atmosphere are exposed to sunlight, ultraviolet light and radiation. Therefore, there are constantly processes of splitting methane molecules into various hydrocarbon radicals and ions. Nitrogen ionization also occurs. As a result, these chemically active elements constantly form new organic compounds of nitrogen and carbon, including very complex ones. Just some kind of biofactory! It is these organic compounds that make Titan's atmosphere appear yellow.

According to calculations, all the methane in the atmosphere would theoretically be used up in 50 million years. However, the satellite has existed for billions of years and the methane in its atmosphere is not decreasing. This means that its reserves are constantly replenished, possibly due to volcanic activity. There are also theories that methane can be produced by special bacteria.

Surface of Titan

The surface of Titan cannot be seen even when close to the satellite, not to mention earth-based telescopes. Thick clouds in the upper layers of the atmosphere are to blame. However, spacecraft have carried out some research in various bands and have revealed a lot about what is hidden under the clouds.

Moreover, in 2005, the Huygens probe separated from the Cassini station and descended directly onto the surface of Titan, transmitting the first real panoramic photographs. The descent through the thick atmosphere took more than two hours. And Cassini itself, over the years spent in orbit of Saturn, took many photographs of both the cloud cover of Titan and its surface in different ranges.

The mountains of Titan, photographed by the Huygens probe from an altitude of 10 km.

The surface of Titan is mostly flat, without strong differences. However, in some places there are also real mountain ranges up to 1 kilometer high. A mountain with a height of 3337 meters was also discovered. Also on the surface of Titan there are many lakes of ethane, and even entire seas - for example, the Kraken Sea is comparable in area to the Caspian Sea. There are many ethane rivers or their courses. At the landing site of the Huygens probe, many round stones are visible - this is a consequence of the influence of liquid on them; in earthly rivers, stones are also gradually ground down.

The stones at the landing site of the Huygens probe were round in shape.

Few craters have been found on the surface of Titan, only 7. The fact is that this satellite has a powerful atmosphere that protects against small meteorites. And if large ones fall, then the crater is quickly filled up with various sediments, collapses, eroded... In general, the weather does its job, and quite quickly all that remains of the huge crater is a neat depression. And most of Tatan’s surface still appears to be a white spot; only a small part of it has been studied.

One of the seas of Titan is the Sea of Ligeia with an area of 100,000 square meters. km.

Along the equator, Titan is surrounded by a curious formation, which scientists initially mistook for a methane sea. However, it turned out that these were dunes made of hydrocarbon dust, which fell as precipitation or was carried by wind from other latitudes. These dunes are parallel and stretch for hundreds of kilometers.

Titan structure

All information about the internal structure of Titan is based on calculations and observations of various processes on it. Inside it is a solid silicate core with a diameter of 3,400 km - it consists of ordinary rocks. Above it is a layer of very dense water ice. Then there is a layer of liquid water mixed with ammonia and another ice layer - the actual surface of the satellite. The top layer, in addition to ice, contains rocks and everything that falls in the form of precipitation.

The structure of Titan.

Saturn, with its powerful attraction, has a strong impact on Titan. Tidal forces “warp” it and cause the core to heat up and the movement of different layers. Therefore, volcanic activity is also observed on Titan - cryovolcanoes have been discovered there, which erupt not with lava, but with water and liquid hydrocarbons.

Subsurface Ocean

The most curious thing about Titan is the possible presence of a subsurface ocean - that same water layer that is located between the surface and the core. If it actually exists, then it completely covers the entire satellite. According to calculations, the water in it contains about 10% ammonia, which serves as antifreeze and lowers the freezing point of water, so it must be there in liquid form. Also, water may contain a certain amount of different salts, as in terrestrial sea water.

According to data collected by Cassini, such a subsurface ocean should actually exist, but it is located at a depth of about 100 km from the surface. There is also evidence that the water contains large amounts of sodium, potassium and sulfur salts, and this water is very salty. Therefore, it is unlikely that any life is possible in it. However, this issue continues to concern scientists and is of great interest. Thanks to this, Titan has become one of the priority objects for future research, as well as Europa, a satellite of Jupiter, which also has a subsurface ocean. Scientists really want to go deep and see what is there in these oceans, especially to look for any forms of life.

Life on Titan

Although the subsurface ocean is most likely too salty and harsh a place for life to originate, scientists do not rule out that it could still be on this satellite. Titanium is extremely rich in hydrocarbons, and various chemical processes with their participation are constantly taking place there; new molecules of rather complex organic substances are constantly being formed. Therefore, the origin of the simplest life cannot be ruled out.

Despite the rather harsh conditions, this could very well happen in methane and ethane lakes. These liquids may well replace water, and their chemical aggressiveness is even lower than that of water, and proteins and nucleic acids may be even more stable than those on Earth.

In general, the conditions on Titan are similar to the conditions that were on Earth at the stage of its inception, except for the extremely low temperatures. Therefore, what once happened on Earth may well happen there.

One curious phenomenon was noticed. There was a hypothesis that the simplest forms of life on Titan could easily feed on acetylene molecules and breathe hydrogen, releasing methane. So, according to Cassini research, there is practically no acetylene on the surface of Titan, and hydrogen also disappears somewhere. This is a fact, but there is no explanation for it yet, and this may well be the result of the presence of certain microorganisms. It is also a fact that Titan’s atmosphere is constantly fed with methane, although a lot of it is blown into space by the solar wind. Cryovolcanoes are one of its sources, lakes and seas are another, and maybe microorganisms also take part in this? On Earth, it was they who transformed the atmosphere and saturated it with oxygen. So all this is very interesting and awaits further research.

And also - when the Sun becomes a red giant, and this will happen in 6 billion years, the Earth will die. But it will become warmer on Titan, and then this satellite will take over the Earth’s baton. Millions of years will pass, and not only the simplest, but also complex forms of life will be able to develop there.

Observation of Saturn's moon Titan

Observing Titan is not difficult. It is the brightest of Saturn's moons, but cannot be seen with the naked eye. But it can be easily seen with 7x50 binoculars, although this is not so easy - its brightness is about 9m.

In a telescope, even a 60mm, Titan is very easy to spot. With more powerful instruments it is visible quite clearly at a great distance from Saturn. For example, not only Titan is clearly visible through the refractor, but some other, smaller satellites of Saturn surrounding it like a swarm. Of course, you won’t be able to see its disk with a small instrument. This requires apertures larger than 200 mm. If you have a telescope with an aperture of 250-300 mm, then you can observe the passage of Titan’s shadow across the planet’s disk.

In contact with

Titan is one of the most interesting satellites of the solar system. Due to its similarity to the Earth, it attracts the attention of many scientists and scientific organizations, and active steps are now being taken towards its further study.

Titan is the second largest moon in the solar system after Ganymede, and also the largest moon of Saturn (see interesting facts about Saturn).
Titan has a very dense atmosphere.
There are rivers and lakes on the surface of Titan, only they are filled not with water, but with liquefied ethane and methane.
Titan's atmosphere consists mainly of nitrogen and methane.
In 2005, the Huygens probe, separated from the unmanned Cassini spacecraft, made a soft landing on the surface of Titan. Huygens transmitted photographs and a recording of wind noise to earth.
Titan is twice the diameter of Mercury, but half the weight.
Titan has no magnetic field.
The height of the mountains on Titan does not exceed several hundred meters.
Methane rains on Titan.
Titan always faces Saturn with the same side.
The sky on Titan is yellow-orange.
The temperature on Titan's surface is about -170 degrees Celsius.
Titan always experiences strong winds, especially in the upper atmosphere. Storms and hurricanes are not uncommon here.
Beneath Titan's surface there is a liquid ocean of very salty water laced with ammonia.
Titan has cryovolcanoes that spew a mixture of water and various carbons.
Scientists suggest that methane-producing bacteria may well exist on Titan.
Titan is 80% heavier than the Moon. It accounts for 95% of the mass of all Saturn's moons.
There is a hypothesis that Titan was once captured by the gravity of Saturn and became its satellite (see facts about the satellites of the planets).
Titan's atmosphere is ten times thicker than Earth's. It extends over four hundred kilometers in height.
The atmospheric pressure on the surface of Titan is one and a half Earth pressures.
The surface of Titan cannot be observed from space in the optical range due to dense clouds.
It took Huygens two and a half hours to descend and land by parachute.
There are no pronounced impact craters on Titan, which indicates its geological activity.

Titan is the largest satellite of Saturn (diameter - 5150 km) and the only satellite of the solar system with a dense atmosphere through which it is impossible to observe the surface of this satellite. The pressure at the surface is approximately 1.6 times higher than the pressure of the earth's atmosphere. Temperature - minus 170-180°C. Titan is larger than the planet Mercury, although it is inferior in mass. Its gravity is approximately one-seventh that of Earth.

Basic information about this mysterious satellite was obtained quite recently using the Huygens spacecraft, which entered Titan's dense atmosphere and landed on its surface in 2005.

Structure

Titan has a composition about the same as most satellites of the giant planets - about half ice and the same amount of rock. Probably a rock core with a diameter of 3400 km, on top of which several layers of ice of varying degrees of crystallization are formed. Half the mass of rocks contains potassium. It is assumed that there may be methane springs on the surface, where methane rivers originate. Scientists suggest that methane reserves on the surface of Titan must be constantly renewed from some unknown source inside Saturn's moon, i.e. methane is constantly destroyed as a result of photochemical processes in the upper atmosphere. That. its current quantity will disappear in 20 million years. If the methane observed today is only a remnant of a much larger amount of this gas, which has now all but disappeared, the carbon isotope ratio of CH4 molecules should be close to what is measured for nitrogen and oxygen (on Earth). Since this is not observed, methane must be constantly renewed. One source of methane may be volcanic activity.

Atmosphere

As already mentioned, Titan has a dense atmosphere, several hundred kilometers thick. 95% consists of nitrogen. Thus, Titan and Earth are the only bodies in the solar system that have a dense atmosphere with a predominant nitrogen content. The remaining 5% is predominantly methane, there are also traces of ethane, diacetylene, methyl acetylene, cyanoacetylene, acetylene, propane, carbon dioxide, carbon monoxide, cyanogen, and helium.

On Titan, methane should perform the same function as water on earth, and go through the cycle - precipitation, collection on the surface, evaporation, condensation, precipitation.

In the upper layers of the atmosphere, under the influence of ultraviolet solar radiation, methane and nitrogen decompose and form complex hydrocarbon compounds. Some of them, according to the Cassini mass spectrometer, contain at least 7 carbon atoms. And among nitrogen compounds, nitriles have been identified - a kind of precursors of amino acids.

During its descent, the Huygens probe detected wind at altitudes from 9.6 to 19.2 kilometers. The wind speed was 25.6 kilometers per hour.

The spacecraft's instruments detected a thick hazy (or cloudy) layer of methane at altitudes of 17.6-19.2 kilometers, where the atmospheric pressure was approximately 0.5 atmospheres. There was methane fog below as well.

The temperature of the atmosphere (in the initial phase of descent) was 70.5 degrees Kelvin (minus 202.6 Celsius), while on the surface of the planet the “air” was slightly warmer: 93.8 degrees Kelvin (minus 179.3 Celsius). Celsius).

Scientists were especially interested in the mystery of ethane clouds, which turned out to be much smaller over Titan than theoretical models predicted. The fact is that solar ultraviolet radiation constantly destroys methane molecules, which the atmosphere of Saturn’s satellite is very rich in, and one of the by-products of this reaction is ethane.

Now planetary scientists from Arizona have made the process of ethane cycling on this amazing planet clearer and helped to understand where it disappears.

In the area of Titan's Arctic Circle, between 51 and 69 degrees latitude, at an altitude of 30-60 kilometers, Cassini instruments captured large ethane clouds. Observations indicate that surface ethane deposits should be located specifically in the polar regions, and not distributed globally, as previously assumed. This may partly explain the absence of ethane oceans and ethane clouds in Titan's low latitudes. It's possible that right now, at the planet's north pole, ethane is being released as rain or, if temperatures are cold enough, as snow. And when the new season begins, ethane will fall at the south pole.

According to scientists, ethane should accumulate at the poles like polar ice. Ethane also dissolves in methane, which is what the local rain is known to consist of. Scientists suggest that during the polar winter, methane lakes are formed in the lowlands, which are also rich in ethane. Perhaps these are the same lakes that Cassini recently discovered.

If ethane were produced in Titan's atmosphere at current rates throughout the planet's existence, caps of ethane ice two kilometers thick would form at the poles. So far, scientists have no direct evidence of the existence of polar caps on this planet.

However, at the south pole, for example, instruments recorded something like rivers, perhaps originating in the local glaciers. One way or another, in the coming months, the American apparatus will perform a number of flights over the poles of this amazing planet, and more information will be available for analysis.

Surface

Titan's surface is relatively flat; altimetry showed elevation differences of no more than 100 m over several hundred kilometers. At the same time, local elevation differences, as shown by radar data and stereo images obtained by Huygens, can be very significant; Steep slopes are not uncommon on Titan. This is the result of intense erosion by wind and liquid. There are several objects similar to impact craters, presumably filled with hydrocarbons.

Dark and light areas on the surface were also found. One of these bright areas has a shape similar to Australia. Scientists suggest that this is a continent called Xanadu. At the western edge of the filmed area, dark dunes give way to a complex landscape cut by branching river networks, hills and valleys. These narrow river networks flow towards darker areas that may be lakes. A crater was also found here, formed either by an asteroid impact or by water volcanism.

The winding channels of eastern Xanadu end in a dark plain where dunes (found in abundance elsewhere) appear to be absent.

Finally, all this splendor of diverse landscapes is crowned by mountains the size of the Appalachians, which cross the considered region of the gas giant's satellite.

There are also dark areas of similar sizes encircling the satellite along the equator, which were initially identified as methane seas. Radar studies, however, have shown that the dark equatorial regions are universally covered with long parallel rows of dunes, elongated in the direction of the prevailing winds (from west to east) - the so-called. "cat scratches" Only in some places were recorded areas of a flat (possibly liquid) surface, the area corresponding to lakes rather than seas. The dark color of the lowlands is explained by the accumulation of particles of hydrocarbon “dust” falling from the upper layers of the atmosphere and washed away by methane showers from the hills.

In June 2005, Cassini discovered a much darker, very well-defined formation located in a region of very thick (possibly "shower") clouds and which could be identified as a truly liquid lake. It is similar in size and shape to Lake Ontario, which is why it was named Lacus Ontario. It is not yet clear whether there is liquid there, or a dark, dried bottom covered with a sedimentary layer. According to some signs, the active “work” of hydrocarbon liquids on the surface of Titan (rains or springs, streams and rivers gushing from under the surface) is seasonal. Further study of the lake should reveal its mystery.

Already in July 2006, Cassini discovered a dozen lakes up to 110 kilometers in size. Some of them are interconnected by canals, while others, separate, are replenished by rivers. Several of them turned out to be dry (as scientists had previously believed), but some were filled with liquid, apparently a mixture of methane and ethane.

Some lakes probably do not always remain dry, but periodically fill during hydrocarbon rains. However, new data have not yet been able to confidently answer the question - what is the source of these substances.

Total information

Titan's diameter is 5152 km, making it larger than the Moon in diameter by approximately 50%. Christiaan Huygens, a famous Dutch physicist, mechanic, mathematician and astronomer, discovered Titan as the first moon of Saturn in 1655.

Astronomers for a long time believed that its diameter was 5550 km, and it ranked first. The true dimensions were found out later thanks to the Voyager 1 spacecraft.

The surface of this huge moon

Until 2004, scientists did not know what the surface of this unknown celestial body looked like, because... Titan, a satellite of Saturn, was completely enveloped in an incredibly dense envelope of atmosphere, making it difficult to study. But after the Cassini-Huygens apparatus landed on its surface, all questions were resolved.

What we now know is that its surface is still quite young by geological standards, and is covered by sedimentary organic matter and water ice. It is almost all flat, except for a few mountains and craters. The surface temperature is 170-180°C below zero. The atmosphere is mainly composed of nitrogen, some ethane and methane.

The hydrocarbon sea of Ligeia is the second largest, Cassini radar survey

Significant areas of the surface are covered by ethane-methane rivers and lakes. Scientists discovered liquid on this celestial body and proved the presence of an atmosphere, as a result of which a hypothesis was presented that a primitive form of life could exist on Titan.

physical characteristics

A 95% share of the total mass of all satellites surrounding Saturn belongs to Titan. Disputes about where such a huge satellite came from have led to several theories, but scientists have not yet come to a final answer. One theory is as follows: this celestial body could have been formed from a dust cloud, which was subsequently captured by the planet’s gravity. Moreover, this theory also explains such a large difference in the mass of the satellites.

Orbit of movement

The second largest moon in the solar system has an orbit of 1,221,870 km, which is equal to 20.3 Saturn's radii, placing it outside the rings of Saturn. It makes one full circle around the planet in almost 16 days. Moreover, its speed is 5.57 kilometers per second.

Titan, like the Moon, rotates synchronously around its planet. It is precisely because Titan’s revolutions around Saturn and around its own axis coincide that it always looks at the planet from the same side. The rotation trajectory of Saturn is inclined relative to the ecliptic by 26.73′, it is this moment that ensures the change of seasons on the planet itself and its satellites.

Each season lasts approximately 7.5 Earth years, while Saturn itself makes one revolution around the Sun in about 30 years. Based on this, we can assume that the last summer on Titan ended in 2009.

And finally, some of the most spectacular photos of Titan

The idea of a human colony on Saturn's moon Titan may seem crazy. Its temperature hovers at -180° Celsius, and its skies unleash showers of methane and ethane into its hydrocarbon seas. However, Titan may be the only place in the solar system where it still makes sense to build a permanent, self-sustaining settlement. Scientists came to this conclusion by looking at the planets in a new way: ecologically. They considered heavenly neighbors from the point of view of factors necessary for humans. Reflections published in the online publication ScientificAmerican.

This colonization scenario, based on science, technology and culture, is a thought experiment for those who want to think about the distant future.

The starting point was the constancy of human nature: people of the future will have the same key needs as we do. Their home must have energy, a habitable temperature and provide protection from the harsh outside world, including cosmic radiation, which is inevitably dangerous for biological creatures like us.

Until now, most researchers considered the Moon or Mars as a potential habitat for humans. Their important advantage is their proximity to Earth, as well as the fact that a person can potentially visit these cosmic bodies, which cannot be said about other inhabitants of the inner Solar system, Mercury and Venus. Mercury is too close to the Sun, and Venus's atmosphere is poisonous, crushingly heavy and hot due to the greenhouse effect. It is possible to live in balloons high in the atmosphere of Venus, but it is obvious that such housing will never be self-sustaining.

While the Moon and Mars seem like relatively reasonable colonization destinations, they also have intractable problems. They are not protected by the magnetosphere and atmosphere. Cosmic rays and energetic particles from distant supernovae bombard the surface of the Moon and Mars, and people here will never be safe.

Radiation has long been known to cause cancer, but research over the past two years has added a potentially more serious threat: brain damage. Particles rushing through interstellar space, including iron nuclei, destroy brain tissue and reduce cognitive abilities. This is one of the reasons why we cannot send researchers to Mars, much less leave them there for a long time.

On Earth we are protected from cosmic radiation by water in the atmosphere. A settlement on the Moon or Mars would have to be built below the surface to be truly safe from this radiation. An underground shelter is difficult to build. The settlers would have to carry out enormous excavations to dig out rooms that would satisfy their daily needs. So why such difficulties? We can live underground and on Earth, without having to move to Mars.

The closest potential homes to us after Mars can be found among the satellites of Jupiter and Saturn. Among dozens of options, the winner is obvious.

Titan is most similar to our home. It is the only body in the solar system with liquid on its surface, with lakes of methane and ethane that are strikingly similar to those on Earth, and dunes of solid hydrocarbons reminiscent of sand dunes on Earth.

To protect against radiation, Titan has a nitrogen atmosphere 50% thicker than Earth's. Saturn's magnetosphere also provides shelter. The huge amount of hydrocarbons on the surface in solid and liquid form can be used to generate energy. Although the atmosphere lacks oxygen, water ice can be used to produce oxygen by breathing and burning hydrocarbons as fuel.

It’s cold on Titan, but thanks to the dense atmosphere, its inhabitants do not need special spacesuits, in which the inhabitants of the ISS go into outer space; they need warm clothes and respirators. Houses can be made of plastic, produced from the unlimited resources mined on the surface of Titan, and filled with warm air. The simplicity of the design will allow you to create huge living spaces.

The recreational opportunities on Titan will be truly unique. For example, you could fly. Weak gravity combined with a thick atmosphere will allow people to float with wings on their backs. And if the wings fall off, it’s okay, the landing will be soft. The acceleration of free fall on Titan is 7 times less than on Earth.

How will people get there? Not at the moment. Unfortunately, at the moment, even a flight to Mars is dangerous in conditions of cosmic radiation. Humanity needs faster engines to reduce the time travelers will spend in space, otherwise the trip to Titan will take approximately seven years.

We will not leave the Earth soon; before that, scientists must solve the main problems. But thanks to continued investment in space exploration science and health technologies in space, humans will one day set foot on Titan.