Alienígenas Ancestrales de Erich von Daniken“Erich Anton Paul von Däniken” https://youtube/watch?v=N-ds1GMhjRQ LUGARES MISTERIOSOS Alienígenas Ancestrales https://youtube/watch?v=Lg0JpGjdT9Y Alienigenas Ancestrales | El Factor Einstein https://youtube/watch?v=ei4e54kV1yw This is a list of potentially habitable exoplanets candidates ranked by similarity with Earth using the Earth Similarity Index. The list is based on methodology and estimations provided by the Habitable Exoplanets Catalog, which is maintained by the Planetary Habitability Laboratory at UPR-Arecibo. Artists impression of Gliese 581 d, a previously secure but now dubious potentially habitable exoplanet Main article: Habitable zone In astronomy and astrobiology, the circumstellar habitable zone (CHZ or sometimes ecosphere, liquid-water belt, HZ, life zone or Goldilocks zone) is the region around a star where a planet with sufficient atmospheric pressure can maintain liquid water on its surface. A potentially habitable planet implies a terrestrial planet within the CHZ and with conditions roughly comparable to those of Earth (i.e. an Earth analog) and thus potentially favourable to life. Although only about a dozen[citation needed] planets have been confirmed in the habitable zone, the Kepler spacecraft has identified a further 54 candidates[citation needed] and current estimates indicate that there are at least 500 million planets in habitable zones in the Milky Way. On 4 November 2013 astronomers reported, based on Kepler space mission 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,[4][5] 11 billion of which may be orbiting Sun-like stars. The nearest such planet could be 12 light-years away, according to the scientists. List from the Habitable Exoplanets Catalog The data in the following table is from the Habitable Exoplanets Catalog.[7] This habitability index does not take into account the differences in the habitability of certain types of stars and star systems, such as red dwarfs and binary star systems. See habitability of red dwarf systems for more information. Key[edit] The planets listed below are evaluated on seven different criteria: Earth Similarity Index (ESI) — Similarity to Earth on a scale from 0 to 1, with 1 being the most Earth-like. ESI depends on the planets radius, density, escape velocity, and surface temperature. Standard Primary Habitability (SPH) — Suitability for vegetation on a scale from 0 to 1, with 1 being best-suited for growth. SPH depends on surface temperature (and relative humidity if known). Habitable Zone Distance (HZD) — Distance from the center of the stars habitable zone, scaled so that –1 represents the inner edge of the zone, and +1 represents the outer edge. HZD depends on the stars luminosity and temperature and the size of the planets orbit. Habitable Zone Composition (HZC) — Measure of bulk composition, where values close to zero are likely iron–rock–water mixtures. Values below –1 represent bodies likely composed mainly of iron, and values greater than +1 represent bodies likely composed mainly of gas. HZC depends on the planets mass and radius. Habitable Zone Atmosphere (HZA) — Potential for the planet to hold a habitable atmosphere, where values below –1 represent bodies likely with little or no atmosphere, and values above +1 represent bodies likely with thick hydrogen atmospheres (e.g. gas giants). Values between –1 and +1 are more likely to have atmospheres suitable for life, though zero is not necessarily ideal. HZA depends on the planets mass, radius, orbit size, and the stars luminosity. Planetary Class (pClass) — Classifies objects based on thermal zone (hot, warm, or cold, where warm is in the habitable zone) and mass (asteroidan, mercurian, subterran, terran, superterran, neptunian, and jovian). Habitable Class (hClass) — Classifies habitable planets based on temperature: hypopsychroplanets (hP) = very cold (< −50 °C); psychroplanets (P) = cold; mesoplanets (M) = medium-temperature (0–50 °C; not to be confused with the other definition of mesoplanets); thermoplanets (T) = hot; hyperthermoplanets (hT) = very hot (> 100 °C). Mesoplanets would be ideal for complex life, whereas class hP or hT would only support extremophilic life. Non-habitable planets are simply given the class NH.
Posted on: Wed, 22 Oct 2014 06:20:43 +0000
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