With a discussion about the translation of the astrophysical term “habitable zone”, we open a new rubric “ False friend translator”, which will discuss the correctness and adequacy of the translation. Send examples of terms that, in your opinion, are incorrectly translated into Russian, explaining why your proposed translation is better and more accurate than others.

Introduction of new scientific terms- responsible business. You use a ringing word without thinking, and then people will suffer for centuries. Ideal for every new scientific concept it would be desirable to invent a new word that did not have a stable meaning before. But this rarely happens. A good example is the “quark” of physicists. Related concepts are usually called single-root words, which is quite convenient (geology, geography, geomagnetic). But often scientists act contrary to these traditions, giving names according to the principle “what came to mind”. An example from astronomy is “planetary nebulae”, which have nothing to do with planets, which every time has to be explained to non-specialists.

No less careful consideration should be given to the translation of English terms into native language. This has always been a problem: for example, star clusters (star cluster) at the beginning of the 20th century were called star heaps. I’m not even talking about the transliteration of the names of scientists: for example, the astronomer H. N. Russell is presented in Russian-language literature in six versions - Russell, Russell, Ressel, Ressell, Ressel and Russell. For modern search engines these are different people.

AT last years the problem of terminology has become aggravated for several reasons: illiterate journalists and non-professional authors publish their translations on the Web, not bothering to get acquainted with the already existing Russian terminology, but simply transliterating English words. So, the word “transit” began to appear more and more often, meaning the passage of the planet against the background of the disk of a star. For professional astronomers, the terms "passage", "occultation", "eclipse" have their own specific meanings, which are not reflected in the single word "transit".

Unfortunately, in most online publications there is no scientific editing, and even paper publishers rarely allow themselves this “luxury”. It would seem that there is a "Wikipedia", in which the terminology should be clarified by common efforts. Sometimes this really succeeds, but still professionals prefer to invest in one common platform called Wikipedia, leaving the content of Wikipedia (Russian-language) on the conscience of amateur enthusiasts.

When a new and, moreover, unsuccessful term begins to come into circulation, there is time to consider the problem and democratically come to a common opinion. Therefore - as an initiative - I propose to discuss the translation English term “circumstellar habitable zone”, or, in short, “ habitable zone”, which became recent times very popular with researchers of exoplanetary systems.

We are talking about the range of distances from the star, within which the temperature on the surface of the planet lies in the range from 0 to 100°C. At normal atmospheric pressure, this opens up the possibility of the existence liquid water and, therefore, life in its current sense. In domestic publications on this topic, three variants of the translation of the term “ habitable zone” - life zone, habitable zone and habitable zone. Let's try to figure it out.

The complete unsuitability of the term is immediately obvious habitable zone, indicating the presence of living beings in this zone and even hinting at the presence of a person there. "Dictionary of the Russian language" S. I. Ozhegov (1987) defines: inhabited- inhabited by people, having a population; an example is an inhabited island.

Really, " desert island" does not mean at all that it is sterile; there are just no people there.

The broader meaning is Dictionary Russian language” by S. I. Ozhegov and N. Yu. Shvedova (1992): inhabited- inhabited by people, having a population; generally such, where there are living beings. Examples - inhabited earth , island inhabited by seagulls. Anyway, inhabited means inhabited, a " habitable zone"- a populated area in which SOMEONE LIVES. In fact, we are talking about the presence of CONDITIONS FOR LIFE, and not at all about the presence of creatures in it. Obviously, authors who use the term habitable zone are the least sensitive to the meanings of their native language.

What is habitable zone? Word habitability in Russian is. But what is it?

1. Explanatory Dictionary of Ushakov: habitability - the degree of population (about the area).
2. Naval historical directory(A. Loparev, D. Loparev): habitability of the ship - a set of factors that characterize the conditions of stay of people on the ship. Elements of habitability: dimensions of cabins, utility rooms, walkways; composition, dimensions and location of cabin equipment; indicators of vessel roll, vibration, noise, ease of maintenance of ship equipment, instruments, systems, etc.
3. Glossary of terms of the Ministry of Emergency Situations (2010): habitability - a set of factors that characterize the conditions of human life.
4. River Dictionary of A. A. Lapin (2012): habitability of the ship - the duration of the voyage without resupply. Usually applied to tourist ships; calculated in days.

As we see, common denominator of these somewhat different interpretations is the person whose presence is supposed.

Direct transfer habitable according to the dictionary gives the following options - habitable, habitable. We have already dealt with habitability, but habitability, for life, accurately reflects the meaning of the term habitable zone. In general, in English -able speaks of possibility, not availability. Most adequate translation it would be the long expression "livable zone" or the somewhat pretentious "livable zone". A simpler and shorter "zone of life", in my opinion, accurately conveys the meaning English expression. Not the last role is played by the ease of pronunciation. Compare: life zone or habitable zone. I am for the zone of life. And you?

Comments

,
doc. Phys.-Math. sciences, head. Department of Physics and Evolution of Stars, Institute of Astronomy, Russian Academy of Sciences

In my practice, I use the variant "habitable zone", although I undoubtedly admit that Vladimir Surdin is right in the sense that this term does not give an adequate understanding of its essence. But the "livable" zone in this respect is no better, if not worse!

After all, what is habitable zone? This is some rather conventionally defined interval of distances within which the existence of liquid water is possible. Not life, but only water! At the same time, it must be remembered that the possibility of the existence of water does not mean that water exists, and the presence of water does not guarantee viability.

In other words, in this case(as in many others) we are trying to describe in two words a very complex concept. It will not be possible to do this adequately, so it is quite acceptable to use an established translation. Moreover, it is almost always necessary to explain what it means anyway.

In astronomy, this happens all the time, and the examples are endless. From the recent one, one can, for example, recall "near-Earth asteroids", which may not be near-Earth at all in literally this word. We also use another, slightly more exact term- asteroids approaching the Earth - but it is also not ideal in terms of conveying meaning. There have been attempts to introduce the correct term "near-Earth asteroids" - but try to put it into practice! A third of the lecture or report will be spent on delivering it.

In general, I also adhere to a rather conformist position in this respect. When I say planetary nebula”, I don’t worry about the fact that it has nothing to do with the planets. The main thing is that both I and my interlocutor understand what is meant.

In astronomy, there are two-thirds of such controversial terms. Who can guess the meaning of the words "right ascension"? Who would guess that “metallicity” is often referred to as the oxygen content? What about new and supernova stars?

,
translator of M. S. Gorbachev, now the head of the press service of the Gorbachev Foundation

In this matter, of course, Vladimir Surdin is right. The fact is that English language in this case clearly separates the possibility and its implementation: habitable- a place to live inhabited- the place where they live. In most cases, the suffix - able and Russian suffix - received- are quite equivalent ( renewable- renewable), and in the case when there is a negation in the definition, they are completely equivalent (since the possibility cannot be realized: impenetrable- impenetrable, unsinkable- unsinkable, etc.)

But in the case of the word "uninhabited" in Russian, there was some "failure" (which is quite normal in natural languages), and it does not mean "a place where one cannot live", but "a place where one does not live". In English- uninhabited. That's why habitable it is desirable to translate so that the meaning of the English suffix - able was preserved and there was no possibility of misinterpretation. So “zone suitable for life” or “zone of possible life” is correct in meaning and correct in Russian. And the word "habitability" is artificial and unnecessary (although some artificial words may be needed, see the "inventive" experience of Karamzin and his contemporaries).

, science journalist

So far, in Russian there is no unambiguously rigidly fixed translation of the term for habitable zone. Well, actually not in English. They also use the "Goldilocks zone" ( Goldilocks Zone), which allows us to abstract from descriptiveness, but it will be clearly incomprehensible to our reader (our analogue is the fairy tale about Masha and the three bears). We have many uses; “life zone” and “habitable zone” are the most common and, in my opinion, never “erroneous”. A term is a term, it does not have to be supported by a verbal construction that is ideal from all points of view. There is where worst cases, already rigidly fixed; say, the same "planetary nebula" ... Well, what to do - you have to live with it, do not arrange "holivars" every time ...

We had a similar discussion in the Science in Focus magazine. In the end, they chose the "habitable zone" with the ability to sometimes commemorate the "life zone". I was neutral. So be it, although I am not at all against the “life zone” with an appropriate explanation. Nothing worse. The remaining options - "habitable zone", "habitat zone" - were decided to be excluded. “The zone where the existence of water in liquid form in open reservoirs is possible” is, of course, super-cumbersome, it is possible only as an explanation once, and even then in the case when the reader is supposed to be completely ignorant ...

The option proposed by Pavel Palazhchenko (“the zone of possible life”) is also cumbersome and does not explain everything, not to mention the prevalence (the term should be ALREADY widespread if possible, so as not to fall into the margins with the old options, when it finally finally get fixed).

In addition to being cumbersome and not as widespread as possible, the "zone of possible life" is not good because it creates only the illusion of correctness. After all, firstly, we are only talking about water, and secondly, about life in the forms known to us (theoretically, life can arise on a different basis ...).

Out of curiosity, I looked up what term we used earlier in the Trinity Variant. There is a complete mess here. Aleksey Paevsky wrote about the "habitable zone" and "habitable zone" (less often). Boris Stern - about the "habitat zone". Sergey Popov - "terrestrial planets in habitable zones". And only I used to write about the "life zone" (but now in the magazine I correct for the "habitable zone").

I also forgot to say that instead of "zone of life" you can also write "belt of life", that is, the first word in this term can also be argued for a long time and with taste.

A planet orbiting in its parent star's "habitable zone" has the potential to have liquid water on its surface, an essential ingredient for the origin and maintenance of life. But what if the planet is in the habitable zone only part of the time? Can life flourish there?

Life on Earth is fortunate that the area around it suitable for it is stationary and motionless, providing it with a constant source of radiation. But this situation does not exist in every star system. Physicist Tobias Müller and astrophysicist Nader Hagigipur wrote computer program, demonstrating how the position and shape of habitable zones can change rapidly in two- and three-star systems, which are considered extremely common in the universe.

A program they call the "HZ Calculator" creates animations illustrating how the habitable zone warps and evolves for a simulated star system.

On their website, scientists have created and posted a program (and made it available to other researchers), which is an animation of a model of a star system.

The three-star system KIC 4150611 has a peculiar orbit that creates a rapidly changing "habitable zone" (dark green). Black dots are stars.

The animation shows three stars with complex orbits - two of them (K1 and K2) are close to each other, making one revolution around common center masses in less than two Earth days. The third star (A) rotates at a distance from them, spending about several months per revolution around the pair. The orbit of the star A is not circular, so its distance to K1 and K2 varies. When three stars approach each other, they form a single habitat zone. But as they scatter, this zone splits into two separate zones. (In the video above, the dark green area is habitable, while the light green areas show where scientists think there is a possibility of habitation, but this will also depend on other factors, including the nature of the planet's atmosphere.)

The habitable zone of the triple star system KID 5653126. The black dots are the stars, and the dark green area is the habitable zone.

Source: Tobias Müller / Nader Haghighipour / HZ Calculator

In a different interesting scenario, in the star system KID 5653126, the orbit of the stellar pair is tightly coupled to each other and creates a mostly stable habitable zone. A third star orbits the pair and wanders erratically through the habitable zone - a potentially catastrophic event for any planets that may be there.

Houses on Tatooine

Fictional planet Tatooine from the Universe" star wars» is in the orbit of two suns. This place is a harsh desert, but presumably it died after life evolved on it. Scientists have proven that planets around systems with two stars exist in the universe, and that they can even support life. But how such orbits around double stars affect the temperature on the planet?

The HZ Calculator gives some insight into this matter. The real star system Kepler 453 has two stars, one about five times larger than the other. This means that the smaller star practically revolves around the larger one (as opposed to two stars revolving around a point in space between them). By at least one planet has been found to orbit both stars, but the movement of the smaller star means that the amount of radiation reaching the planet changes regularly.

The orbit of two stars in the Kepler 453 system causes a shift in the surrounding habitable zone. white dot shows a potential planet in the system that can be affected by changing radiation levels.

In the animation created by the HZ calculator, the planet's position in the habitable zone is an illustration of how much radiation the planet receives from its parent stars. Over the course of a year, the planet drifts from the middle of the habitable zone (dark green region) to the innermost edge of that zone (light green region), where temperatures can be too hot to sustain liquid water on the planet's surface.

Such a situation would lead to seasonal fluctuations temperatures at the planet's surface, says Elizabeth Tasker, Associate Professor of Solar System Science at the Japan Aerospace Agency (JAXA).

“If there are extreme seasons caused by an eccentric orbit, can we talk about the presence of life? Can life survive under these conditions? Of course, we don't know that yet, but the outlook isn't all that bad."

Taster said exoplanet scientists have suggested that planets that drift along the inner edge of the habitable zone may experience extreme seasons, but still have the potential to hold liquid water during such fluctuations. Possibly on the fictional planet Tatooine, Luke Skywalker's aunt and uncle suffer from an abundance of water during the cool seasons and live by harvesting it during the harsher periods caused by the movement of the two suns.

It is also possible that life forms on the planet go into hibernation or suspended animation during severe hot or cold periods. If so, it may be difficult for Earth scientists to detect them.

Such information may become relevant when scientists begin to search for signs of habitability of alien worlds. With thousands of planets to choose from, where will their eyes go? The HZ Calculator is one of the tools that researchers can use to narrow down the list of planets that need to be explored first.

Müller, professor of mathematics and computer science at the University of Groningen in Germany, said the HZ calculator is useful for illustrating that habitable zones are not static, which can be difficult to understand without a visual aid.

No guarantee

This illustration shows the "habitable zone" of the Earth. Venus and Mars are outside the habitable zone, in a region where only certain conditions would allow liquid water to exist on the surface.

Definition 1

Exoplanets - the so-called planets located outside our home solar system.

Terrestrial astronomers focus on the search for exoplanets in the so-called habitable zone.

habitable zone

Definition 2

The habitable zone is the optimal distance between the studied planet and its star, which allows the planet to have a temperature at which water can be in liquid form, which significantly increases the possibility of the origin of life.

The conditions under which life can arise are determined by factors such as:

• the presence of water in liquid form,
• an atmosphere with the required density,
• variety of chemical elements
• Availability greenhouse gases(water vapor, methane, ammonia, etc.)
• the presence of the sun required amount energy.

The boundaries of the habitable zone are established based on considerations of the possibility of water being in liquid form, since water in this state is necessary component many biochemical reactions.

If the planet is too far from its star, the water freezes; if it is too close, the water evaporates.

When exploring exoplanets in deep space, it is important to keep in mind that there is only a potential, possible habitable zone.

A potential habitable zone is a zone in which there are conditions for the formation of life, but they are not enough for this.

In this case, one should take into account such circumstances as the presence or absence of magnetic field, tectonic activity, duration of the day on the planet, etc.

The above points are dealt with in such a new scientific discipline like astrobiology, which is part of astronomy.

Search for exoplanets in the habitable zone

The problem with finding planets that are in a potential habitable zone is that they are located near stars very far from us.

AT broad sense the search for life forms in the solar system and beyond is the search for biomarkers.

Remark 1

Biomarkers are chemical compounds that are of biological origin.

As an example, one can say that such a biomarker on Earth is the presence of oxygen in the atmosphere. However, the presence of oxygen in the atmosphere of an exoplanet does not mean the presence of life there. So, on a number of planets, oxygen in the atmosphere is a consequence of physical processes, such as the decomposition of water vapor under the influence of ultraviolet radiation, which emit stars.

Mission "Kepler"

One of the most productive space telescopes is the Kepler telescope, named after the famous mathematician Johannes Kepler. Another space telescope, the Hubble, also showed great results.

Thanks to work space telescope Kepler made a qualitative leap in the study of exoplanets.

Remark 2

The Kepler space telescope works with a photometer. This instrument tracks the change in the brightness of a star as the planet passes between it and the telescope. This way of discovering planets is called transit.

As a result of such observations, it was possible to obtain information about the orbit of the planet under study, the mass of the planet and its temperature.

Thus, in the first part of its study, the Kepler space telescope was able to detect about 4,500 potential planet candidates. In order to check the obtained data and make sure that the change in the brightness of the star is associated with the passage of the planet, and not with the peculiarities of the processes in the star itself, in particular, observation of the change in the radial velocity of the star is used.

As a result, on this moment there is a confirmed number of planets - there are about 3600 of them. And there are about 5000 possible candidates for planets.

Proxima Centauri

In August 2016, astronomers confirmed that the closest star to us, Proxima Centauri, has a planet. This planet is called Proxima b.

Proxima Centauri is 4.2 light years from our Sun. This distance means that the light from a given star takes 4.2 years to reach us.

Thus, it turns out that the star closest to us has a planet on which the emergence of life is possible.

The planet Proxima b itself was in the zone of potential habitability. And at the same time relatively close to our Earth.

Proxima b is 200 times closer to its star than the Earth is to the Sun. But since the star Proxima Centauri is a red dwarf, it is colder and weaker than our Sun.

It is noted that the planet Proxima b fell into the zone of tidal capture of a star and now revolves around it like the Earth's satellite - the Moon. As a result, one side of the planet turned out to be warm, and the other cold.

Thus, the possibility arises of the formation of suitable conditions for the origin of life at the boundaries of the dark and warm hemispheres. But for this life there is a problem associated with the fact that Proxima Centauri is a red dwarf, which is characterized by high activity. Flares occur on such stars, there are coronal ejections of magma, the level ultraviolet radiation higher than on Earth by 20-30 times.

Thus, in order to form favorable conditions, capable of leading to the emergence of life on such a planet, it is necessary to have enough dense atmosphere. Such an atmosphere is needed to protect against the radiation of a red dwarf.

Astronomical means of observation, developing, will make it possible to better study the planet closest to us. Earth specialists will be able to study the atmosphere of this planet and understand what is happening there, determine the presence or absence of greenhouse gases, study the climate, and also find or refute the presence of biomarkers on this planet.

For a more detailed and detailed study of it, it is planned to put into operation new space and ground-based telescopes.

So, in Russia, work is underway on the Spektr-UF space telescope project.

The launch of the James Webb Space Telescope, which should replace the almost legendary Hubble telescope, has been postponed to the early 2020s.

The new telescope will have a higher resolution, which will allow us to learn more about the composition of the atmospheres and the structure of exoplanets.

The boundaries of the habitable zone are established based on the requirement that the planets in it have water in liquid state, since it is a necessary solvent in many biomechanical reactions.

Beyond the outer edge of the habitable zone, the planet does not get enough solar radiation to compensate for radiation losses, and its temperature will drop below the freezing point of water. A planet closer to the sun than the inner edge of the habitable zone would be overheated by its radiation, causing the water to evaporate.

Calculating the position of the boundaries of the habitable zone and their displacement over time is rather complicated (in particular, due to negative feedback in the CNO cycle, which can make the star more stable). Even for the solar system, estimates of the boundaries of the habitable zone vary widely. In addition, the possibility of the existence of liquid water on the planet strongly depends on physical parameters the planet itself.

The distance from the star where this phenomenon is possible is calculated from the size and luminosity of the star. The center of the habitable zone for a particular star is described by the equation:

Average habitable zone radius in astronomical units,

star luminosity,

Luminosity of the Sun.

Formulas for distances to the inner and outer boundaries of the habitable zone can be derived from the equations heat balance for planets that would be at these distances. We write the heat balance equation mathematically in differential form, that is, for a unit surface area of ​​the planet when the star is at its zenith.

Equilibrium flux of body radiation energy:

Absorbed energy from the star:

where E is the illumination, A is the albedo of the planet.

Then the heat balance equation in differential form has the form

Illumination is the amount of energy falling per unit area in 1 second.

Can be expressed in terms of the temperature of the star and the distance between the star and the planet:

where r is the distance between the star and the planet. Let's find this distance from the heat balance equation

You can also calculate the boundaries differently, using the illumination created by the star at each edge, . This illumination mainly depends on the luminosity, L, but to some extent also on the effective temperature, T e, stars. The lower the temperature, the greater the infrared part of the radiation. The more infrared radiation, the greater the thermal effect on the planet. Let us denote the critical illumination at the inner boundary of the habitable zone S bri (T e ) , the equation for it in units of the solar constant:

and the equation for illumination at the outer edge of the habitable zone:

where T e in degrees Kelvin. Distances from the star to the boundaries of the habitable zone in AU:

where L is the luminosity of the star in solar units and S bri (T e ) and S Bro (T e ) in units of the solar constant.

Luminosity ,L, and effective temperature, T e , found from observations of the stars. L (in solar units) is obtained from the equation:

where V- apparent magnitude and sun- bolometric correction. Visible bolometric magnitude is the sum (V + sun).d is the distance to the star in parsecs.

Theoretical calculations have shown that the climate of planets near the outer boundary of the habitable zone can be unstable. It will fluctuate between long cold periods and occasional warm ones. As a result, apparently, highly developed life on such planets will not be able to arise. This can impose significant restrictions on the size of habitable zones in the direction of their reduction.