Habitable zone for complex life

Last updated
Natural shielding against space weather and solar wind, such as the magnetosphere depicted in this artistic rendition, is required for planets to sustain life for prolonged periods. Magnetosphere rendition.jpg
Natural shielding against space weather and solar wind, such as the magnetosphere depicted in this artistic rendition, is required for planets to sustain life for prolonged periods.

A Habitable Zone for Complex Life (HZCL) is a range of distances from a star suitable for complex aerobic life. Different types of limitations preventing complex life give rise to different zones. [1] Conventional habitable zones are based on compatibility with water. [2] Most zones start at a distance from the host star and then end at a distance farther from the star. A planet would need to orbit inside the boundaries of this zone. With multiple zonal constraints, the zones would need to overlap for the planet to support complex life. The requirements for bacterial life produce much larger zones than those for complex life, which requires a very narrow zone. [3] [4] [5]

Contents

Exoplanets

The first confirmed exoplanets was discovered in 1992, several planets orbiting the pulsar PSR B1257+12. [6] Since then the list of exoplanets has grown to the thousands. [7] Most exoplanets are hot Jupiter planets, that orbit very close the star. [8] Many exoplanets are super-Earths, that could be a gas dwarf or large rocky planet, like Kepler-442b at a mass 2.36 times Earths. [9]

Star

Unstable stars are young and old stars, or very large or small stars. Unstable stars have changing solar luminosity that changes the size of the life habitable zones. Unstable stars also produce extreme solar flares and coronal mass ejections. Solar flares and coronal mass ejections can strip away a planet's atmosphere that is not replaceable. Thus life habitable zones require and very stable star like the Sun, at ±0.1% solar luminosity change. [10] [11] Finding a stable star, like the Sun, is the search for a solar twin, with solar analogs that have been found. [12] Proper star metallicity, size, mass, age, color, and temperature are also very important to having low luminosity variations. [13] [14] [15] The Sun is unique as it is metal rich for its age and type, a G2V star. The Sun is currently in its most stable stage and has the correct metallicity to make it very stable. [16] Dwarf stars (red dwarf/orange dwarf/brown dwarf/subdwarf) are not only unstable, but also emit low energy, so the habitable zone is very close to the star and planets become tidally locked on the timescales needed for the development of life. [17] Giant stars (subgiant/giant star/red giant/red supergiant) are unstable and emit high energy, so the habitable zone is very far from the star. [18] Multiple-star systems are also very common and are not suitable for complex life, as the planet orbit would be unstable due to multiple gravitational forces and solar radiation. Liquid water is possible in Multiple-star systems. [19] [20] [21] [22]

Named habitable zones

A conventional habitable zone is defined by liquid water.

Named habitable zones for complex life

Over time and with more research, astronomers, cosmologists and astrobiologist have discovered more parameters needed for life. Each parameter could have a corresponding zone. Some of the named zones include: [29] [30]

Some factors that depend on planetary distance and may limit complex aerobic life have not been given zone names. These include:

Life

Life on Earth is carbon-based. However, some theories suggest that life could be based on other elements in the periodic table. [101] Other elements proposed have been silicon, boron, arsenic, ammonia, methane and others. As more research has been done on life on Earth, it has been found that only carbon's organic molecules have the complexity and stability to form life. [102] [103] [104] Carbon properties allows for complex chemical bonding that produces covalent bonds needed for organic chemistry. Carbon molecules are lightweight and relatively small in size. Carbon's ability to bond to oxygen, hydrogen, nitrogen, phosphorus, and sulfur (called CHNOPS) is key to life. [105] [106] [107]

See also

Related Research Articles

<span class="mw-page-title-main">Exoplanet</span> Planet outside the Solar System

An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not then recognized as such. The first confirmation of the detection occurred in 1992. A different planet, first detected in 1988, was confirmed in 2003. According to statistics from the NASA Exoplanet Archive, As of 21 August 2024, there are 5,747 confirmed exoplanets in 4,289 planetary systems, with 962 systems having more than one planet. The James Webb Space Telescope (JWST) is expected to discover more exoplanets, and to give more insight into their traits, such as their composition, environmental conditions, and potential for life.

<span class="mw-page-title-main">Rare Earth hypothesis</span> Hypothesis that complex extraterrestrial life is improbable and extremely rare

In planetary astronomy and astrobiology, the Rare Earth hypothesis argues that the origin of life and the evolution of biological complexity, such as sexually reproducing, multicellular organisms on Earth, and subsequently human intelligence, required an improbable combination of astrophysical and geological events and circumstances. According to the hypothesis, complex extraterrestrial life is an improbable phenomenon and likely to be rare throughout the universe as a whole. The term "Rare Earth" originates from Rare Earth: Why Complex Life Is Uncommon in the Universe (2000), a book by Peter Ward, a geologist and paleontologist, and Donald E. Brownlee, an astronomer and astrobiologist, both faculty members at the University of Washington.

<span class="mw-page-title-main">Habitable zone</span> Orbits where planets may have liquid surface water

In astronomy and astrobiology, the habitable zone (HZ), or more precisely the circumstellar habitable zone (CHZ), 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 HZ 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 HZ 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.

<span class="mw-page-title-main">Planetary habitability</span> Known extent to which a planet is suitable for life

Planetary habitability is the measure of a planet's or a natural satellite's potential to develop and maintain environments hospitable to life. Life may be generated directly on a planet or satellite endogenously or be transferred to it from another body, through a hypothetical process known as panspermia. Environments do not need to contain life to be considered habitable nor are accepted habitable zones (HZ) the only areas in which life might arise.

<span class="mw-page-title-main">HD 69830 d</span> Ice giant exoplanet orbiting HD 69830

HD 69830 d is an exoplanet likely orbiting within the habitable zone of the star HD 69830, the outermost of three such planets discovered in the system. It is located approximately 40.7 light-years (12.49 parsecs, or 3.8505×1014 km) from Earth in the constellation of Puppis. The exoplanet was found by using the radial velocity method, from radial-velocity measurements via observation of Doppler shifts in the spectrum of the planet's parent star.

<span class="mw-page-title-main">Ocean world</span> Planet containing a significant amount of water or other liquid

An ocean world, ocean planet or water world is a type of planet that contains a substantial amount of water in the form of oceans, as part of its hydrosphere, either beneath the surface, as subsurface oceans, or on the surface, potentially submerging all dry land. The term ocean world is also used sometimes for astronomical bodies with an ocean composed of a different fluid or thalassogen, such as lava, ammonia or hydrocarbons. The study of extraterrestrial oceans is referred to as planetary oceanography.

<span class="mw-page-title-main">Gliese 581d</span> Contested super-Earth orbiting Gliese 581

Gliese 581d is a doubtful, and frequently disputed, exoplanet candidate orbiting within the Gliese 581 system, approximately 20.4 light-years away in the Libra constellation. It was the third planet claimed in the system and the fourth or fifth in order from the star. Multiple subsequent studies found that the planetary signal in fact originates from stellar activity, and thus the planet does not exist, but this remains disputed.

<span class="mw-page-title-main">Super-Earth</span> Type of exoplanet

A Super-Earth is a type of exoplanet with a mass higher than Earth's, but substantially below those of the Solar System's ice giants, Uranus and Neptune, which are 14.5 and 17 times Earth's, respectively. The term "super-Earth" refers only to the mass of the planet, and so does not imply anything about the surface conditions or habitability. The alternative term "gas dwarfs" may be more accurate for those at the higher end of the mass scale, although "mini-Neptunes" is a more common term.

Extraterrestrial liquid water is water in its liquid state that naturally occurs outside Earth. It is a subject of wide interest because it is recognized as one of the key prerequisites for life as we know it and is thus surmised to be essential for extraterrestrial life.

<span class="mw-page-title-main">Habitability of natural satellites</span> Measure of the potential of natural satellites to have environments hospitable to life

The habitability of natural satellites is the potential of moons to provide habitats for life, though it is not an indicator that they harbor it. Natural satellites are expected to outnumber planets by a large margin and the study of their habitability is therefore important to astrobiology and the search for extraterrestrial life. There are, nevertheless, significant environmental variables specific to moons.

<span class="mw-page-title-main">Earth analog</span> Planet with environment similar to Earths

An Earth analog, also called an Earth analogue, Earth twin, or second Earth, is a planet or moon with environmental conditions similar to those found on Earth. The term Earth-like planet is also used, but this term may refer to any terrestrial planet.

<span class="mw-page-title-main">Discoveries of exoplanets</span> Detecting planets located outside the Solar System

An exoplanet is a planet located outside the Solar System. The first evidence of an exoplanet was noted as early as 1917, but was not recognized as such until 2016; no planet discovery has yet come from that evidence. What turned out to be the first detection of an exoplanet was published among a list of possible candidates in 1988, though not confirmed until 2003. The first confirmed detection came in 1992, with the discovery of terrestrial-mass planets orbiting the pulsar PSR B1257+12. The first confirmation of an exoplanet orbiting a main-sequence star was made in 1995, when a giant planet was found in a four-day orbit around the nearby star 51 Pegasi. Some exoplanets have been imaged directly by telescopes, but the vast majority have been detected through indirect methods, such as the transit method and the radial-velocity method. As of 24 July 2024, there are 7,026 confirmed exoplanets in 4,949 planetary systems, with 1007 systems having more than one planet. This is a list of the most notable discoveries.

<span class="mw-page-title-main">Habitability of red dwarf systems</span> Possible factors for life around red dwarf stars

The theorized habitability of red dwarf systems is determined by a large number of factors. Modern evidence suggests that planets in red dwarf systems are unlikely to be habitable, due to their low stellar flux, high probability of tidal locking, likely lack of magnetospheres and atmospheres, and the high stellar variation such planets would experience. However, the sheer number and longevity of red dwarfs could provide ample opportunity to realize any small possibility of habitability.

<span class="mw-page-title-main">Kepler-186f</span> Terrestrial exoplanet orbiting Kepler-186

Kepler-186f is an Earth-sized exoplanet orbiting within the habitable zone of the red dwarf star Kepler-186, the outermost of five such planets discovered around the star by NASA's Kepler space telescope. It is located about 580 light-years from Earth in the constellation of Cygnus.

<span class="mw-page-title-main">Superhabitable world</span> Hypothetical type of planet or moon that may be better-suited for life than Earth

A superhabitable world is a hypothetical type of planet or moon that is better suited than Earth for the emergence and evolution of life. The concept was introduced in a 2014 paper by René Heller and John Armstrong, in which they criticized the language used in the search for habitable exoplanets and proposed clarifications. The authors argued that knowing whether a world is located within the star's habitable zone is insufficient to determine its habitability, that the principle of mediocrity cannot adequately explain why Earth should represent the archetypal habitable world, and that the prevailing model of characterization was geocentric or anthropocentric in nature. Instead, they proposed a biocentric approach that prioritized astrophysical characteristics affecting the abundance and variety of life on a world's surface.

HIP 57274 d is an exoplanet orbiting the K-type main sequence star HIP 57274 about 84.5 light-years (26 parsecs, or nearly 8.022×1016 km) from Earth in the constellation Cetus. It orbits within the outer part of its star's habitable zone, at a distance of 1.01 AU. The exoplanet was found by using the radial velocity method, from radial-velocity measurements via observation of Doppler shifts in the spectrum of the planet's parent star.

<span class="mw-page-title-main">TRAPPIST-1e</span> Earth-size exoplanet orbiting TRAPPIST-1

TRAPPIST-1e, also designated as 2MASS J23062928-0502285 e, is a rocky, close-to-Earth-sized exoplanet orbiting within the habitable zone around the ultracool dwarf star TRAPPIST-1, located 40.7 light-years away from Earth in the constellation of Aquarius. Astronomers used the transit method to find the exoplanet, a method that measures the dimming of a star when a planet crosses in front of it.

<span class="mw-page-title-main">Habitable Exoplanets Observatory</span> Proposed space observatory to characterize exoplanets atmospheres

The Habitable Exoplanet Observatory (HabEx) is a space telescope concept that would be optimized to search for and image Earth-size habitable exoplanets in the habitable zones of their stars, where liquid water can exist. HabEx would aim to understand how common terrestrial worlds beyond the Solar System may be and determine the range of their characteristics. It would be an optical, UV and infrared telescope that would also use spectrographs to study planetary atmospheres and eclipse starlight with either an internal coronagraph or an external starshade.

<span class="mw-page-title-main">Kepler-1649c</span> Earth-size exoplanet orbiting Kepler-1649

Kepler-1649c is an Earth-sized exoplanet, likely rocky, orbiting within the habitable zone of the red dwarf star Kepler-1649, the outermost planet of the planetary system discovered by Kepler’s space telescope. It is located about 301 light-years (92 pc) away from Earth, in the constellation of Cygnus.

References

  1. "Not All Habitable Zones Are Created Equal". www.spacedaily.com.
  2. 1 2 Schwieterman, Edward W.; Reinhard, Christopher T.; Olson, Stephanie L.; Harman, Chester E.; Lyons, Timothy W. (June 10, 2019). "A Limited Habitable Zone for Complex Life". The Astrophysical Journal. 878 (1): 19. arXiv: 1902.04720 . Bibcode:2019ApJ...878...19S. doi: 10.3847/1538-4357/ab1d52 .
  3. "New Discovery Shows 'Habitable Zone for Complex Life' is Much More Narrow than Original Estimates – NASA". June 10, 2019.
  4. Williams, Matt; Today, Universe. "Complex life might require a very narrow habitable zone". phys.org.
  5. How do you form a habitable planet?, Georgia State University Research
  6. Wolszczan, A.; Frail, D. A. (1992). "A planetary system around the millisecond pulsar PSR1257 + 12". Nature. 355 (6356): 145–147. Bibcode:1992Natur.355..145W. doi:10.1038/355145a0. S2CID   4260368.
  7. "Exoplanet and Candidate Statistics". exoplanetarchive.ipac.caltech.edu.
  8. "Orbital Evolution of planets in Extra-solar systems". users.auth.gr. 5 February 2024.
  9. Valencia, V.; Sasselov, D. D.; O'Connell, R. J. (2007). "Radius and structure models of the first super-earth planet". The Astrophysical Journal . 656 (1): 545–551. arXiv: astro-ph/0610122 . Bibcode:2007ApJ...656..545V. doi:10.1086/509800. S2CID   17656317.
  10. 1 2 3 Green, James; Boardsen, Scott; Dong, Chuanfei (February 20, 2021). "Magnetospheres of Terrestrial Exoplanets and Exomoons: Implications for Habitability and Detection". The Astrophysical Journal Letters. 907 (2): L45. arXiv: 2012.11694 . Bibcode:2021ApJ...907L..45G. doi: 10.3847/2041-8213/abd93a .
  11. 1 2 Brasch, Klaus R. (July 7, 2023). "Is Earth the only Goldilocks planet? | Astronomy.com".
  12. "Solar Variability and Terrestrial Climate – NASA Science". science.nasa.gov.
  13. "Stellar Luminosity Calculator". astro.unl.edu.
  14. The Effects of Solar Variability on Earth's Climate: A Workshop Report. National Academies Press. November 12, 2012. doi:10.17226/13519. ISBN   978-0-309-26564-5.
  15. "Most of Earth's twins aren't identical, or even close! | ScienceBlogs". scienceblogs.com.
  16. 1 2 "NASA Astrobiology". astrobiology.nasa.gov.
  17. Barnes, Rory, ed. (2010). Formation and Evolution of Exoplanets. John Wiley & Sons. p. 248. ISBN   978-3527408962. Archived from the original on 2023-08-06. Retrieved 2016-08-16.
  18. Voisey, Jon (February 23, 2011). "Plausibility Check - Habitable Planets around Red Giants".
  19. "Multiple Star Systems - NASA Science". science.nasa.gov.
  20. Busetti, F.; Beust, H.; Harley, C. (2018). "Stability of planets in triple star systems". Astronomy & Astrophysics. 619: A91. arXiv: 1811.08221 . Bibcode:2018A&A...619A..91B. doi:10.1051/0004-6361/201833097.
  21. Martin, David V. (June 9, 2018). Deeg, Hans J.; Belmonte, Juan Antonio (eds.). Handbook of Exoplanets. Springer International Publishing. pp. 1–26. doi:10.1007/978-3-319-30648-3_156-1 via Springer Link.
  22. https://scholar.archive.org/work/cmmv5cns2ffvrlchovuaccjpne/access/wayback/http://www.uta.edu/physics/main/faculty/musielak/info/CEM.pdf Stringent Criteria For Stable And Unstable Planetary Orbits In Stellar Binary Systems, M. Cuntz,1 J. Eberle,1 and Z. E. Musielak1, 2007 August 27]
  23. "Big Idea 2.1 – NASA Science". science.nasa.gov.
  24. "What Is the Habitable Zone?". Exoplanet Exploration: Planets Beyond our Solar System.
  25. "Planets in the habitable zone". www.esa.int.
  26. 1 2 3 "Which habitable zone planets are the best candidates for detecting life? | astrobites".
  27. "Second Earth-sized World Found in System's Habitable Zone". Exoplanet Exploration: Planets Beyond our Solar System.
  28. "The Habitable Zone | Astronomy 801: Planets, Stars, Galaxies, and the Universe". www.e-education.psu.edu.
  29. Taylor, Stuart Ross (29 July 2004). "Why can't planets be like stars?". Nature. 430 (6999): 509. Bibcode:2004Natur.430..509T. doi: 10.1038/430509a . PMID   15282586. S2CID   12316875.
  30. Stern, Alan. "Ten Things I Wish We Really Knew In Planetary Science" . Retrieved 2009-05-22.
  31. Cowing, Keith (March 30, 2023). "The Ultraviolet Habitable Zone Of Exoplanets". Astrobiology.
  32. Spinelli, Riccardo; Borsa, Francesco; Ghirlanda, Giancarlo; Ghisellini, Gabriele; Haardt, Francesco (April 13, 2023). "The ultraviolet habitable zone of exoplanets". Monthly Notices of the Royal Astronomical Society. 522 (1): 1411–1418. arXiv: 2303.16229 . doi: 10.1093/mnras/stad928 .
  33. "Habitable zones :: Vera Dobos". veradobos.webnode.page.
  34. Hall, C.; Stancil, P. C.; Terry, J. P.; Ellison, C. K. (May 1, 2023). "A New Definition of Exoplanet Habitability: Introducing the Photosynthetic Habitable Zone". The Astrophysical Journal Letters. 948 (2): L26. arXiv: 2301.13836 . Bibcode:2023ApJ...948L..26H. doi: 10.3847/2041-8213/acccfb .
  35. Association, American Lung. "Ozone". www.lung.org.
  36. Proedrou, Elisavet; Hocke, Klemens (June 1, 2016). "Characterising the three-dimensional ozone distribution of a tidally locked Earth-like planet". Earth, Planets and Space. 68 (1): 96. Bibcode:2016EP&S...68...96P. doi: 10.1186/s40623-016-0461-x .
  37. "Photochemical Smog - an overview | ScienceDirect Topics". www.sciencedirect.com.
  38. Yang, Jun; Boué, Gwenaël; Fabrycky, Daniel C.; Abbot, Dorian S. (May 1, 2014). "Strong Dependence of the Inner Edge of the Habitable Zone on Planetary Rotation Rate". The Astrophysical Journal. 787 (1): L2. arXiv: 1404.4992 . Bibcode:2014ApJ...787L...2Y. doi:10.1088/2041-8205/787/1/L2 via NASA ADS.
  39. "Rotation of planets influences habitability". phys.org.
  40. Jansen, T. (March 19, 2021). "Effects of Rotation Rate on the Habitability of Earth-like Planets using NASA's ROCKE-3D GCM". Bulletin of the AAS. 53 (3): 0603. Bibcode:2021BAAS...53c0603J via baas.aas.org.
  41. The Moon's Role in the Habitability of the Earth, Georgia State University Research
  42. Seasons, Georgia State University Research
  43. Ecliptic Plane, Georgia State University Research
  44. Axis Tilt is Critical for Life, Georgia State, astr.gsu.edu
  45. Starr, Michelle (July 8, 2021). "This One Planetary Feature May Be Crucial For The Rise of Complex Life in The Universe". ScienceAlert.
  46. Conference, Goldschmidt. "Goldilocks planets 'with a tilt' may develop more complex life". phys.org.
  47. Jenkins, Gregory S. (March 27, 2000). "Global climate model high-obliquity solutions to the ancient climate puzzles of the Faint-Young Sun Paradox and low-altitude Proterozoic glaciation". Journal of Geophysical Research: Atmospheres. 105 (D6): 7357–7370. Bibcode:2000JGR...105.7357J. doi:10.1029/1999JD901125 via CrossRef.
  48. Becker, Juliette; Seligman, Darryl Z.; Adams, Fred C.; Styczinski, Marshall J. (March 1, 2023). "The Influence of Tidal Heating on the Habitability of Planets Orbiting White Dwarfs". The Astrophysical Journal Letters. 945 (2): L24. arXiv: 2303.02217 . Bibcode:2023ApJ...945L..24B. doi: 10.3847/2041-8213/acbe44 .
  49. Hasler, Caroline (February 17, 2022). "Tidally Locked and Loaded with Questions". Eos.
  50. "New conditions for life on other planets: Tidal effects change 'habitable zone' concept". ScienceDaily.
  51. Vladimir S. Airapetian, “Space Weather Affected Habitable Zones around Active Stars,” AASTCS5 Radio Exploration of Planetary Habitability, Proceedings of the Conference, May 7–12, 2017 in Palm Springs, CA, published in the Bulletin of the American Astronomical Society 49, no. 3, id. 101.05
  52. Smith, David S.; Scalo, John M. (September 20, 2009). "Habitable zones exposed: astrosphere collapse frequency as a function of stellar mass". Astrobiology. 9 (7): 673–681. Bibcode:2009AsBio...9..673S. doi:10.1089/ast.2009.0337. PMID   19778278 via PubMed.
  53. Time History of the Martian Dynamo from Crater Magnetic Field Analysis Journal of Geophysical Research: Planets 118, no. 7 (July 2013), by Robert J. Lillis et al., page 1488–1511
  54. Timing of the Martian Dynamo Nature 408, by G. Schubert, C. T. Russell, and W. B. Moore, December 7, 2000: page 666–667
  55. Langlais, Benoit; Thébault, Erwan; Houliez, Aymeric; Purucker, Michael E.; Lillis, Robert J. (2019). "A New Model of the Crustal Magnetic Field of Mars Using MGS and MAVEN". Journal of Geophysical Research: Planets. 124 (6): 1542–1569. Bibcode:2019JGRE..124.1542L. doi:10.1029/2018JE005854. ISSN   2169-9100. PMC   8793354 . PMID   35096494.
  56. "Space Radiation is Risky Business for the Human Body – NASA". September 19, 2017.
  57. Collinson, Glyn A.; Frahm, Rudy A.; Glocer, Alex; Coates, Andrew J.; Grebowsky, Joseph M.; Barabash, Stas; Domagal-Goldman, Shawn D.; Fedorov, Andrei; Futaana, Yoshifumi; Gilbert, Lin K.; Khazanov, George; Nordheim, Tom A.; Mitchell, David; Moore, Thomas E.; Peterson, William K.; Winningham, John D.; Zhang, Tielong L. (June 28, 2016). "The electric wind of Venus: A global and persistent "polar wind"-like ambipolar electric field sufficient for the direct escape of heavy ionospheric ions". Geophysical Research Letters. 43 (12): 5926–5934. Bibcode:2016GeoRL..43.5926C. doi:10.1002/2016GL068327. S2CID   54886960 via CrossRef.
  58. Collinson, Glyn; Mitchell, David; Glocer, Alex; Grebowsky, Joseph; Peterson, W. K.; Connerney, Jack; Andersson, Laila; Espley, Jared; Mazelle, Christian; Sauvaud, Jean-André; Fedorov, Andrei; Ma, Yingjuan; Bougher, Steven; Lillis, Robert; Ergun, Robert; Jakosky, Bruce (November 16, 2015). "Electric Mars: The first direct measurement of an upper limit for the Martian "polar wind" electric potential". Geophysical Research Letters. 42 (21): 9128–9134. Bibcode:2015GeoRL..42.9128C. doi:10.1002/2015GL065084 via CrossRef.
  59. "Strong 'electric wind' strips planets of oceans and atmospheres". UCL News. June 20, 2016.
  60. "Eccentric Habitable Zones". Exoplanet Exploration: Planets Beyond our Solar System.
  61. Zubritsky, Elizabeth. "Jupiter's Youthful Travels Redefined Solar System". NASA. Archived from the original on 1 March 2017. Retrieved 4 November 2015.
  62. Beatty, Kelly (16 October 2010). "Our "New, Improved" Solar System". Sky & Telescope . Retrieved 4 November 2015.
  63. Sanders, Ray (23 August 2011). "How Did Jupiter Shape Our Solar System?". Universe Today . Retrieved 4 November 2015.
  64. See, V.; Jardine, M.; Vidotto, A. A.; Petit, P.; Marsden, S. C.; Jeffers, S. V.; Nascimento, J. D. do (October 1, 2014). "The effects of stellar winds on the magnetospheres and potential habitability of exoplanets". Astronomy & Astrophysics. 570: A99. arXiv: 1409.1237 . Bibcode:2014A&A...570A..99S. doi:10.1051/0004-6361/201424323 via www.aanda.org.
  65. "Planetary Habitability page of the Trieste Astrobiology Group". wwwuser.oats.inaf.it.
  66. Vladilo, Giovanni; Murante, Giuseppe; Silva, Laura; Provenzale, Antonello; Ferri, Gaia; Ragazzini, Gregorio (March 25, 2013). "The Habitable Zone Of Earth-Like Planets With Different Levels Of Atmospheric Pressure". The Astrophysical Journal. 767 (1): 65. arXiv: 1302.4566 . Bibcode:2013ApJ...767...65V. doi:10.1088/0004-637x/767/1/65.
  67. "Mars & Comets – NASA". mars.nasa.gov.
  68. Nair, C. P. Reghunadhan; Unnikrishnan, Vibhu (April 18, 2020). "Stability of the Liquid Water Phase on Mars: A Thermodynamic Analysis Considering Martian Atmospheric Conditions and Perchlorate Brine Solutions". ACS Omega. 5 (16): 9391–9397. doi:10.1021/acsomega.0c00444. PMC   7191838 . PMID   32363291.
  69. "How Does Barometric Pressure Affect Humans?". MedicineNet.
  70. Tarver, William J.; Volner, Keith; Cooper, Jeffrey S. (January 20, 2023). "Aerospace Pressure Effects". StatPearls. StatPearls Publishing. PMID   29262037 via PubMed.
  71. Complex life may be possible in only 10% of all galaxies, 24 Nov 2014, By Adrian Cho cience.org]
  72. "Which Galaxies are Best Suited for the Evolution of Alien Life?". Discover Magazine.
  73. "What's killing galaxies? Large survey reveals how star formation is shut down in extreme regions of the Universe".
  74. Canada, National Research Council (November 2, 2021). "What's killing galaxies? Large survey reveals how star formation is shut down in extreme regions of the Universe". nrc.canada.ca.
  75. "New study examines which galaxies are best for intelligent life". ScienceDaily.
  76. 1 2 Vera, Matias; Alonso, Sol; Coldwell, Georgina (November 1, 2016). "Effect of bars on the galaxy properties". Astronomy & Astrophysics. 595: A63. arXiv: 1607.08643 . Bibcode:2016A&A...595A..63V. doi:10.1051/0004-6361/201628750 via www.aanda.org.
  77. What is a peculiar galaxy?, Monthly Notices of the Royal Astronomical Society, Volume 286, Issue 4, April 1997, Pages 969–978, by O. Lahav and A. Nairn
  78. "Star Formation in Irregular Galaxies". ned.ipac.caltech.edu.
  79. "Irregular Galaxy: A Unique Collections of Stars – Let's Talk Stars". www.letstalkstars.com. February 17, 2023.
  80. The connection between star formation and metallicity evolution in barred spiral galaxies, Monthly Notices of the Royal Astronomical Society, Volume 431, Issue 3, 21 May 2013, Pages 2560–2575, doi.org/10.1093/mnras/stt354, 20 March 2013
  81. Yu, Si-Yue; Ho, Luis C. (January 31, 2019). "On the Connection between Spiral Arm Pitch Angle and Galaxy Properties". The Astrophysical Journal. 871 (2): 194. arXiv: 1812.06010 . Bibcode:2019ApJ...871..194Y. doi: 10.3847/1538-4357/aaf895 .
  82. "What process creates and maintains the beautiful spiral arms around spiral galaxies? I've been told that density waves are responsible—so where do the density waves come from?". Scientific American.
  83. Hall, Shannon. "The Milky Way's Spiral Arms May Have Carved Earth's Continents". Scientific American.
  84. "The origin of elements, by Miller, astro.umd.edu" (PDF).
  85. Mahoney, Trevor (July 13, 2020). "Why Different Types of Galaxies May Affect the Development of Life".
  86. Mason, Paul (January 1, 2018). "The Supergalactic Habitable Zone". American Astronomical Society. 231: 401.04. Bibcode:2018AAS...23140104M via NASA ADS.
  87. Mason, P. A.; Biermann, P. L. (November 1, 2017). "The Large-Scale Structure of Habitability in the Universe". Habitable Worlds 2017. 2042: 4149. Bibcode:2017LPICo2042.4149M via NASA ADS.
  88. Mason, Paul (January 1, 2019). "The dawn of habitable conditions for complex life in the Universe". American Astronomical Society Meeting. 233: 432.06. Bibcode:2019AAS...23343206M via NASA ADS.
  89. "The Cosmic Blueprint | Paul Davies". cosmos.asu.edu.
  90. "New study dramatically narrows the search for advanced life in the universe | UCR News | UC Riverside". news.ucr.edu.
  91. Gribbin, John (2011). Alone in the Universe: Why our planet is unique. Wiley
  92. Ward, Peter D.; Brownlee, Donald (2000). Rare Earth: Why Complex Life is Uncommon in the Universe. Copernicus Books (Springer Verlag). ISBN 978-0-387-98701-9.
  93. Gonzales, Guillermo; Richards, Jay W (2004). The Privileged Planet. Regnery Publishing, Inc.
  94. "Lucky Planet - Why Earth is Exceptional & Life In The Universe".
  95. "The origin and rise of complex life | Royal Society". royalsociety.org. 7 December 2022.
  96. "Ice, Snow, and Glaciers and the Water Cycle | U.S. Geological Survey". www.usgs.gov.
  97. Deitrick, Russell; Barnes, Rory; Quinn, Thomas R.; Armstrong, John; Charnay, Benjamin; Wilhelm, Caitlyn (January 16, 2018). "Exo-Milankovitch Cycles. I. Orbits and Rotation States". The Astronomical Journal. 155 (2): 60. arXiv: 1712.10060 . Bibcode:2018AJ....155...60D. doi: 10.3847/1538-3881/aaa301 .
  98. Deitrick, Russell; Barnes, Rory; Bitz, Cecilia; Fleming, David; Charnay, Benjamin; Meadows, Victoria; Wilhelm, Caitlyn; Armstrong, John; Quinn, Thomas R. (June 1, 2018). "Exo-Milankovitch Cycles. II. Climates of G-dwarf Planets in Dynamically Hot Systems". The Astronomical Journal. 155 (6): 266. arXiv: 1805.00283 . Bibcode:2018AJ....155..266D. doi: 10.3847/1538-3881/aac214 .
  99. Tereza Pultarova (June 14, 2022). "Milankovitch cycles: What are they and how do they affect Earth?". Space.com.
  100. Laboratory, By Alan Buis, NASA's Jet Propulsion. "Milankovitch (Orbital) Cycles and Their Role in Earth's Climate". Climate Change: Vital Signs of the Planet.{{cite web}}: CS1 maint: multiple names: authors list (link)
  101. "Knowledge reference for national forest assessments – modeling for estimation and monitoring". www.fao.org. Archived from the original on January 13, 2020. Retrieved Feb 20, 2019.
  102. Allison, Steven D.; Vitousek, Peter M. (2005-05-01). "Responses of extracellular enzymes to simple and complex nutrient inputs". Soil Biology and Biochemistry. 37 (5): 937–944. Bibcode:2005SBiBi..37..937A. doi:10.1016/j.soilbio.2004.09.014. ISSN   0038-0717.
  103. "Astrobiology". Biology Cabinet. September 26, 2006. Retrieved 2011-01-17.
  104. "Polycyclic Aromatic Hydrocarbons: An Interview With Dr. Farid Salama". Astrobiology magazine. 2000. Archived from the original on 2008-06-20. Retrieved 2008-10-20.
  105. Lipkus, Alan H.; Yuan, Qiong; Lucas, Karen A.; et al. (2008). "Structural Diversity of Organic Chemistry. A Scaffold Analysis of the CAS Registry". The Journal of Organic Chemistry. 73 (12). American Chemical Society (ACS): 4443–4451. doi: 10.1021/jo8001276 . PMID   18505297.
  106. Molnar, Charles; Gair, Jane (May 14, 2015). "2.3 Biological Molecules". Introduction to the Chemistry of Life via opentextbc.ca.
  107. Education (2010). "CHNOPS: The Six Most Abundant Elements of Life". Pearson Education . Pearson BioCoach. Archived from the original on 27 July 2017. Retrieved 2010-12-10. Most biological molecules are made from covalent combinations of six important elements, whose chemical symbols are CHNOPS. ... Although more than 25 types of elements can be found in biomolecules, six elements are most common. These are called the CHNOPS elements; the letters stand for the chemical abbreviations of carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur.