page_title: Superhabitable planet
section_title: Profile summary
hierarchical_section_title: Superhabitable planet / Profile summary
caption_attribution_description: Español: Comparación de tamaño Kepler-442b y de la Tierra English: Size comparison Kepler-442b and Earth
context_page_description: A superhabitable planet is a hypothetical type of exoplanet or exomoon that may be better suited than Earth for the emergence and evolution of life. The concept was introduced in 2014 by René Heller and John Armstrong, who have criticized the language used in the search for habitable planets, so they propose clarifications because a circumstellar habitable zone is not enough to define a planet's habitability. Heller and Armstrong state that it is not clear why Earth should offer the most suitable physicochemical parameters to living organisms, because "planets could be non-Earth-like, yet offer more suitable conditions for the emergence and evolution of life than Earth did or does." While still assuming that life requires water, they hypothesize that Earth may not represent the optimal planetary habitability conditions for maximum biodiversity; in other words, they define a superhabitable world as a terrestrial planet or moon that could support more diverse flora and fauna than there are on Earth, as it would empirically show that its environment is more hospitable to life.
context_section_description: Despite the scarcity of information available, the hypotheses presented above on superhabitable planets can be summarized as a preliminary profile, even if there is no scientific consensus. 
  Mass: approximately 2M⊕.
  Radius: to maintain a similar Earth density, its radius should be between 1.2 and 1.3R⊕.
  Oceans: percentage of surface area covered by oceans should be Earth-like but more distributed, without large continuous land masses. The oceans should be shallow; the light then will penetrate easier through the water and will reach the fauna and flora, stimulating an abundance of life down in the ocean.
  Distance: shorter distance from the center of the habitable zone of the system than Earth.
  Temperature: average surface temperature of about 25 °C (77 °F).
  Star and age: belonging to an intermediate K-type star with an older age than the Sun (4.5 billion years) but younger than 7 billion years.
  Atmosphere: somewhat denser than Earth's and with a higher concentration of oxygen. That will make life larger and more abundant.
  There is no confirmed exoplanet that meets all these requirements. After updating the database of exoplanets on 23 July 2015, the one that comes closest is Kepler-442b, belonging to an orange dwarf star, with a radius of 1.34R⊕ and a mass of 2.34M⊕, but with an estimated surface temperature of −2.65 °C (27.23 °F).
caption: A size comparison and artist's impression of Kepler-442b (1.34 R⊕) to the Earth (right).
exif: {"Image Orientation": "Horizontal (normal)", "Image XResolution": "150", "Image YResolution": "150", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop CS5 Windows", "Image DateTime": "2015:04:21 18:29:00", "Image ExifOffset": "164", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "302", "Thumbnail JPEGInterchangeFormatLength": "3527", "EXIF ColorSpace": "Uncalibrated", "EXIF ExifImageWidth": "1063", "EXIF ExifImageLength": "591"}