Definitions for Circumstellar Habitable Zone
cir·cum·stel·lar hab·it·able zone

WikipediaRate this definition:0.0 / 0 votes

1. Circumstellar habitable zone

   In astronomy and astrobiology, the circumstellar habitable zone (CHZ), or simply the habitable zone, is the range of orbits around a star within which a planetary surface can support liquid water given sufficient atmospheric pressure. The bounds of the CHZ are based on Earth's position in the Solar System and the amount of radiant energy it receives from the Sun. Due to the importance of liquid water to Earth's biosphere, the nature of the CHZ and the objects within it may be instrumental in determining the scope and distribution of planets capable of supporting Earth-like extraterrestrial life and intelligence. The habitable zone is also called the Goldilocks zone, a metaphor, allusion and antonomasia of the children's fairy tale of "Goldilocks and the Three Bears", in which a little girl chooses from sets of three items, ignoring the ones that are too extreme (large or small, hot or cold, etc.), and settling on the one in the middle, which is "just right". Since the concept was first presented in 1953, many stars have been confirmed to possess a CHZ planet, including some systems that consist of multiple CHZ planets. Most such planets, being either super-Earths or gas giants, are more massive than Earth, because massive planets are easier to detect. On November 4, 2013, astronomers reported, based on Kepler data, that there could be as many as 40 billion Earth-sized planets orbiting in the habitable zones of Sun-like stars and red dwarfs in the Milky Way. About 11 billion of these may be orbiting Sun-like stars. Proxima Centauri b, located about 4.2 light-years (1.3 parsecs) from Earth in the constellation of Centaurus, is the nearest known exoplanet, and is orbiting in the habitable zone of its star. The CHZ is also of particular interest to the emerging field of habitability of natural satellites, because planetary-mass moons in the CHZ might outnumber planets.In subsequent decades, the CHZ concept began to be challenged as a primary criterion for life, so the concept is still evolving. Since the discovery of evidence for extraterrestrial liquid water, substantial quantities of it are now thought to occur outside the circumstellar habitable zone. The concept of deep biospheres, like Earth's, that exist independently of stellar energy, are now generally accepted in astrobiology given the large amount of liquid water known to exist within in lithospheres and asthenospheres of the Solar System. Sustained by other energy sources, such as tidal heating or radioactive decay or pressurized by non-atmospheric means, liquid water may be found even on rogue planets, or their moons. Liquid water can also exist at a wider range of temperatures and pressures as a solution, for example with sodium chlorides in seawater on Earth, chlorides and sulphates on equatorial Mars, or ammoniates, due to its different colligative properties. In addition, other circumstellar zones, where non-water solvents favorable to hypothetical life based on alternative biochemistries could exist in liquid form at the surface, have been proposed.

WikidataRate this definition:1.0 / 1 vote

1. Circumstellar habitable zone

   In astronomy and astrobiology, the circumstellar habitable zone is the region around stars within which planetary-mass objects with commensurate atmospheric pressure could support liquid water at the surface. The CHZ is inferred from known requirements of Earth's biosphere, the Earth's position in the Solar System and the amount of radiant energy it receives from the Sun. To many, studying such objects in the CHZ appears to be the best way to estimate the scope of life in the universe and locate extraterrestrial life. Since the concept of the CHZ was first presented in 1953, numerous planets have now been discovered in the CHZ. Most are more massive than the Earth since such planets are easier to detect. The number of planets with Earth-like composition orbiting within circumstellar habitable zones has been estimated to be anywhere from 500 million to over 150 billion. The CHZ is also of particular interest to the emerging field of natural satellite habitability, since moons are believed to greatly outnumber planets. In recent decades, the CHZ concept has been broadly challenged as a primary criterion for life. Since the discovery of evidence for extraterrestrial liquid water, substantial quantities of it are now believed to occur outside of the circumstellar habitable zone. Sustained by other energy sources, such as tidal heating or radioactive decay or pressurized by other non-atmospheric means, the basic conditions for water-dependent life may be found even in interstellar space. In addition, other circumstellar zones, where non-water solvents favorable to hypothetical life based on alternative biochemistries could exist in liquid form at the surface, have been proposed. Nevertheless, the CHZ remains important in the search for extraterrestrial intelligence.

How to pronounce Circumstellar Habitable Zone?

1. Alex

   US English

   David

   US English

   Mark

   US English

   Daniel

   British

   Libby

   British

   Mia

   British

   Karen

   Australian

   Hayley

   Australian

   Natasha

   Australian

   Veena

   Indian

   Priya

   Indian

   Neerja

   Indian

   Zira

   US English

   Oliver

   British

   Wendy

   British

   Fred

   US English

   Tessa

   South African

How to say Circumstellar Habitable Zone in sign language?

Numerology

1. Chaldean Numerology

   The numerical value of Circumstellar Habitable Zone in Chaldean Numerology is: 7

2. Pythagorean Numerology

   The numerical value of Circumstellar Habitable Zone in Pythagorean Numerology is: 4

References

1. ^ Wikipedia
   https://en.wikipedia.org/wiki/Circumstellar_Habitable_Zone
2. ^ Wikidata
   https://www.wikidata.org/w/index.php?search=Circumstellar Habitable Zone