Astronomy:Habitable exoplanet
A potentially habitable exoplanet is a hypothetical type of planet that has liquid water and may support life.[1] As of March 2020, a total of 55 potentially habitable exoplanets have been found.[2] Of those, one is believed to be Sub-terran (Mars-size), 20 Terran (Earth-size) and 34 Super Terran (Super Earths).[3] The main feature of potentially habitable exoplanets is that they have to be located in the habitable zone of their stellar systems (although life is also possible outside this zone, and estimates of the extent of the zone can also vary widely).
Characteristics
Mass
In order to be potentially habitable, an exoplanet would have to have a mass between 0.1 and 10 Earth masses.[4]
Radius
The radius of a habitable exoplanet would range between 0.5 and 2.5 Earth radii.[5]
Temperature
The temperature among the habitable exoplanets discovered so far are estimated to range from 182 Kelvin (Kepler 186f) to 285 Kelvin (Tau Ceti e).[6]
Host star
It is believed that F, G, K and M-type stars could host habitable exoplanets.[7] G-type stars would allow to host the exoplanets most similar to Earth, that is, Earth-like planets.[8] K-type stars would provide the necessary conditions for super habitable exoplanets, which are exoplanets that could be more habitable than Earth.[9]
M-type stars also considered possible hosts of habitable exoplanets, even those with flares such as Proxima b. However, it is important to bear in mind that flare stars could greatly reduce the habitability of exoplanets by eroding their atmosphere.[10]
About half of the stars similar in temperature to the Sun could have a rocky planet able to support liquid water on its surface, according to research using data from NASA's Kepler Space Telescope.[11]
See also
- List of potentially habitable exoplanets
- Planetary habitability
- Earth analog
- Habitable exomoon
- Superhabitable exoplanet
References
- ↑ "Habitable Exoplanet Observatory (HabEx)". https://www.jpl.nasa.gov/habex/.
- ↑ "The Habitable Exoplanets Catalog - Planetary Habitability Laboratory @ UPR Arecibo". http://phl.upr.edu/projects/habitable-exoplanets-catalog.
- ↑ "The Habitable Exoplanets Catalog - Planetary Habitability Laboratory @ UPR Arecibo". http://phl.upr.edu/projects/habitable-exoplanets-catalog.
- ↑ Raymond, S. N.; Quinn, T.; Lunine, Jonathan I. (2005). "High-resolution simulations of the final assembly of Earth-like planets 2: water delivery and planetary habitability". Astrobiology 7 (1): 66–84. doi:10.1089/ast.2006.06-0126. PMID 17407404. http://cds.cern.ch/record/895337.
- ↑ "On the radius of habitable planets". https://www.aanda.org/articles/aa/pdf/2014/01/aa22293-13.pdf.
- ↑ "The Habitable Exoplanets Catalog - Planetary Habitability Laboratory @ UPR Arecibo". http://phl.upr.edu/projects/habitable-exoplanets-catalog.
- ↑ "Habitable Exoplanet Observatory (HabEx)". https://www.jpl.nasa.gov/habex/.
- ↑ Petigura, Erik A.; Howard, Andrew W.; Marcy, Geoffrey W. (2013-11-26). "Prevalence of Earth-size planets orbiting Sun-like stars". Proceedings of the National Academy of Sciences 110 (48): 19273–19278. doi:10.1073/pnas.1319909110. ISSN 0027-8424. PMID 24191033. Bibcode: 2013PNAS..11019273P.
- ↑ Heller, René; Armstrong, John (2014). "Superhabitable Worlds". Astrobiology 14 (1): 50–66. doi:10.1089/ast.2013.1088. ISSN 1531-1074. PMID 24380533. Bibcode: 2014AsBio..14...50H.
- ↑ "Habitable Exoplanet Observatory (HabEx)". https://www.jpl.nasa.gov/habex/.
- ↑ Center, By Frank Tavares NASA's Ames Research. "About Half of Sun-Like Stars Could Host Rocky, Potentially Habitable Planets". https://exoplanets.nasa.gov/news/1664/about-half-of-sun-like-stars-could-host-rocky-potentially-habitable-planets/.
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