The James Webb Space Telescope is capable of searching the “carbonaceous” atmospheres of exoplanets to search for alien life. “We have a way to find out if there is liquid water on another planet. And we can achieve this in the next few years.”
A team of researchers, including scientists from the Massachusetts Institute of Technology (MIT) and the University of Birmingham, suggest that if rocky worlds like Earth, outside the solar system, have less carbon dioxide in their atmospheres than other planets in the same system , this may be a sign that they contain liquid water. And as we know from the formation of life on our planet and the conditions necessary to support life here, the presence of liquid water is a key indicator of potential habitability.
While searching for key chemical components that indicate habitability on exoplanets is only within the reach of current technology, depleted carbon dioxide is a signature that JWST is now poised to detect.
The James Webb Space Telescope is an orbiting infrared observatory. The largest space telescope with the largest mirror ever launched by mankind. Originally called the “Next Generation Space Telescope”. Launch: December 25, 2021.
Astronomers have discovered that complex organic compounds are present even in the most ancient galaxies in the Universe. Scientists made this discovery while studying data collected by the orbiting James Webb Telescope during observations of the galaxy SPT0418-47, located in the constellation Hours and approximately 12 billion light-years from Earth.
As of December 6, 2021, there were 59 confirmed exoplanets in the catalog of habitable exoplanets. For comparison, Earth and 3 other terrestrial planets of the Solar System have been added to the list.
The basic level of vitality is a parameter that determines the water-thermal suitability of the planet’s climate for the existence of terrestrial producers (vegetation). The parameter takes a value in the range from 0 to 1, where “1” is the most suitable conditions for life and is a function of surface temperature and relative humidity. The value “1” is assigned to planets with an average surface temperature of 25 °C, which is the most optimal for most plant species; “0” – planets with temperatures above 50 °C and below 0 °C. For exoplanets, only the temperature component is used and it is assumed that water is present on the planet.
Distance from the habitable zone is a parameter that determines the distance of the planet from the center of the habitable zone of the parent star. Planets in the habitable zone have values from −1 to +1, where “0” denotes the center of the habitable zone, and −1 and +1 indicate its inner and outer edges. The distance from the habitable zone is a function of the star’s luminosity, its temperature, and the distance to the planet.
The composition of the habitable zone is a parameter that determines the gross composition of the exoplanet. Values close to 0 indicate bodies consisting of a mixture of iron, stone and water. Values below −1 indicate bodies composed primarily of iron, and values above +1 indicate bodies composed primarily of gas. HZC depends on mass and radius.
The atmosphere of the habitable zone is a parameter characterizing the ability of an exoplanet to maintain an atmosphere. Values below −1 indicate bodies with little or no atmosphere. Values above +1 indicate bodies with a dense hydrogen atmosphere (gas giants, for example). Values between −1 and +1 are likely to have an atmosphere suitable for life, but 0 does not necessarily indicate ideal conditions. HZA depends on the mass, radius, orbit of the planet and the luminosity of the star.
Planetary class is a parameter characterizing planetary bodies as a combination of three temperature classes and seven mass categories. The temperature class depends on the position of the planet relative to the habitable zone and can be of three types: hot, warm and cold (warm corresponds to the habitable zone). The mass category is divided into the following types: asteroid, mercury, mini-Earth, earth, super-Earth, Neptune and Jupiter. The classification can be applied to exoplanets (including satellites), as well as any planets in the Solar System.
Habitability class is a parameter that is a classification of only habitable worlds (Earth-like planets in the habitable zone) and consists of five temperature categories:
– hypopsychroplanets (class hP, very cold planets) – temperature from −50 °C and below;
– psychroplanets (class P, cold planets) – temperature from −50 to 0 °C;
– mesoplanets (class M, planets with moderate temperatures, a typical mesoplanet is the Earth) – temperature from 0 to 50 ° C;
– thermoplanets (class T, hot planets) – temperature from 50 to 100 °C;
– hyperthermoplanets (class hT, very hot planets) – temperatures from 100 °C and above.
This naming method was borrowed from microbiology, where it is used to classify microorganisms depending on the temperature favorable to their growth. Class M includes planets with surface temperatures between 0 and 50 °C, suitable for supporting complex life forms. Other classes imply conditions suitable only for extremophiles. The universal class NH is used to designate planets uninhabitable.
There is also a variety of terrestrial exoplanets:
– Super Earth.
A super-Earth (or super-Earth) is a class of planets with a mass greater than that of Earth but less than the mass of Neptune. Planets of this type were discovered relatively recently around other stars. Super-Earths have relatively small masses and are difficult to detect using Doppler spectroscopy. Super-Earths have been found in every third planetary system discovered by the Kepler telescope, leading scientists to speculate about the reasons for their absence from the Solar System. This term does not imply any specific characteristics, such as surface temperature, composition, orbital parameters, habitability, or the presence of certain ecosystems. The boundary between super-Earths and gas giants is fuzzy, and is estimated to be about 10 Earth masses.
– Mega-earth.
Mega-Earth is a massive terrestrial exoplanet that is at least ten times the mass of Earth. Mega-Earths are significantly more massive than super-Earths. The term mega-Earth was first coined in 2014, following the discovery of the exoplanet Kepler-10 c, with a mass comparable to that of Neptune and a density significantly greater than that of Earth.
– Mini-Earth.
Mini-Earth is a planet significantly less massive than Earth and Venus. In the solar system, this type of planets includes Mars and Mercury. Planets of this type are almost impossible to detect using the radial velocity method due to their low mass, and therefore the transit method is currently the most effective.
– Planet-ocean.
An ocean planet is a type of planet composed primarily of ice, rock, and metals (in approximately equal proportions by mass to simplify the model). Depending on the distance to the parent star, they can be completely covered by an ocean of liquid water up to 100 km deep (the exact value depends on the radius of the planet), at greater depths the pressure becomes so great that the water can no longer exist in a liquid state and solidifies, forming such modifications ice, like Ice V, VI, VII, X and others. So far, only one such planet has been discovered – GJ 1214 b.
– Chthonic planet.
A chthonic planet or Jupiter that has lost its gaseous envelope is a hypothetical class of exoplanets that formed from a gas giant as a result of the evaporation of gases from its atmosphere. Such volatilization occurs on hot Jupiters due to their extreme proximity to the star – the planet gradually loses its atmosphere. As a result, only a small rocky or metallic core remains from the gas giant, and the planet becomes a terrestrial planet. An example of a planet losing its gaseous envelope is HD 209458 b (Osiris).
– Nuclear-free planet.
A nuclear-free planet is a hypothetical type of terrestrial planet whose representatives completely lack a metallic core. The entire planet (or its solid part) in this case, by default, consists only of a huge mantle. Since a nuclear-free planet lacks a core, it will also lack a magnetic field. In addition, it should be a little more kernel-containing. But at the current stage of exoplanet research, it is impossible to distinguish between nuclear-free and core-containing planets.
– Iron planet.
An iron planet is a type of terrestrial exoplanet that consists primarily of an iron-rich core followed by a thin layer of mantle, or no mantle. The most similar astronomical body of this type in the Solar System is Mercury, but it is likely that larger iron exoplanets exist in the Universe.
– Carbon planet.
A carbon planet is a theoretical type of Earth-like exoplanet that was predicted by American astrophysicist Mark Kuechner. The condition for the formation of planets of this type is a high carbon content in the protoplanetary disk and a low oxygen content. In terms of chemical properties, such a planet will be quite different from terrestrial planets such as Earth, Mars and Venus, which are built primarily on the basis of silicon and oxygen, and do not contain much carbon in their composition.
– A planet covered in lava.
A lava planet is a hypothetical type of Earth-like exoplanet whose surface is partially or completely covered in molten lava. Such a planet can exist if it is located very close to its parent star and/or is constantly heated by tidal forces. In addition, any terrestrial planet can temporarily transition into the state of a lava planet if the planet has recently experienced a collision with another large space object, and the surface has not yet cooled.
– Desert planet.
Desert Planet – A planet with one primary biome, having a primarily desert climate with little or no natural precipitation. A typical desert planet is Mars. Many terrestrial planets would be considered desert planets by this definition. However, the term is often used to refer to those desert planets that retain the possibility of life.
– Orphan planet (rocky).
An orphan planet (other possible names include rogue planet, planemo, wanderer planet, interstellar planet, free-floating planet, free-flying planet, quasi-planet or solitary planet) is an interstellar object that has a mass comparable to a planetary one and is spherical in shape and is essentially a planet, but not gravitationally bound to any star, brown dwarf or other planet (although it may have satellites). If such a planet is located in a galaxy, it orbits directly around the galactic core (the orbital period is usually very long). Otherwise, we are talking about an intergalactic planet, and the planet does not orbit anything.
– Super-Io.
Super-Io is a proposed class of Earth-like exoplanets with increased volcanic activity. The surface of these planets is constantly changing due to material ejected by volcanoes, which is reminiscent of one of the four Galilean moons of Jupiter, Io, due to the large amount of sulfur on the surface, which is associated with continuous active volcanism. This similarity is why the class of exoplanets got its name.
– Super Venus
Super-Venus is a proposed class of Earth-like exoplanets with a dense greenhouse atmosphere. It has a weak magnetic field. In this case, water vapor (split by solar radiation into individual chemical elements) is carried away by the solar wind into interplanetary space. It has been established that the atmosphere of the planet Venus is still losing hydrogen and oxygen. Without much water on the planet, its atmosphere becomes saturated with carbon dioxide. Millions of years ago, the Earth’s atmosphere was also abundantly saturated with carbon dioxide released from the bowels of the earth during volcanic eruptions. But with the appearance of plants on Earth, carbon dioxide became more and more bound up, as it was used to form plant matter (and then buried in the form of coal and limestone). The high content of free carbon dioxide in the atmosphere of Venus apparently indicates that there has never been organic life there, similar to that on Earth.
