Mesoplanet - Citizendia

Mesoplanet is a term coined by Isaac Asimov to refer to planetary bodies with sizes smaller than Mercury but larger than Ceres. Isaac Asimov (c January 2 1920 &ndash April 6 1992 ˈaɪzək ˈæzɪmʌv originally Исаак Озимов but now transcribed into Russian as, was a Russian A planet, as defined by the International Astronomical Union (IAU is a celestial body Orbiting a Star or stellar remnant that is Ceres (ˈsɪəriːz Assuming "size" is defined by linear dimension (or by volume), mesoplanets should be approximately 1000 km to 5000 km in diameter. This is a list of Solar System objects by radius, arranged in descending order of mean volumetric Radius. The classification would include Eris, Pluto, (136472) 2005 FY₉, (136108) 2003 EL₆₁, 90377 Sedna, 90482 Orcus and 50000 Quaoar; it might also include (84522) 2002 TC₃₀₂ and 20000 Varuna if they are towards the larger end of current estimates. TemplateInfobox Planet.--> 90377 Sedna (ˈsɛdnə) is a Trans-Neptunian TemplateInfobox Planet. --> 90482 Orcus (, Orcus originally known by the Provisional designation This article is about 20000 Varuna, a minor planet For other uses of the word see Varuna (disambiguation 20000 Varuna (

Size comparison between Earth's Moon, Neptune's (probably captured) moon Triton and several of the largest minor planets, including the mesoplanets.

The term was coined in Asimov's essay "What's in a Name?", which first appeared in The Los Angeles Times in the late 1980s and was reprinted in his 1991 book Frontiers. An essay is usually a short piece of writing It is often written from an author's personal point of view. The Los Angeles Times (also known as the LA Times) is a daily Newspaper published in Los Angeles California and distributed The 1980s was the decade spanning from January 1 1980 to December 31 1989. Year 1991 ( MCMXCI) was a Common year starting on Tuesday (link will display full calendar of the Gregorian Calendar. In the essay, Asimov noted that the solar system has a large number of planetary bodies (as opposed to the sun and natural satellites) and stated that lines dividing "major planets" from minor planets were necessarily arbitrary. The Solar System consists of the Sun and those celestial objects bound to it by Gravity. The Sun (Sol is the Star at the center of the Solar System. A natural satellite or moon is a Celestial body that Orbits a Planet or smaller body which is called the primary. Minor planet is a term used since the 19th century to describe objects such as Asteroids that are in Orbit around the Sun but are not Planets Asimov then pointed out that there was a large gap in size between Mercury, the smallest planetary body that was considered to be undoubtedly a major planet, and Ceres, the largest planetary body that was considered to be undoubtedly a minor planet. Only one planetary body known at the time, Pluto, fell within the gap. Rather than arbitrarily decide whether Pluto belonged with the major planets or the minor planets, Asimov suggested that any planetary body that fell within the size gap between Mercury and Ceres be called a mesoplanet, since mesos in the Greek language means "middle. Greek (el ελληνική γλώσσα or simply el ελληνικά — "Hellenic" is an Indo-European language, spoken today by 15-22 million people mainly "

In 2006 the IAU ratified the classification "dwarf planet" which includes Ceres, Pluto, Eris, and a not yet determined number of smaller objects. A dwarf planet, as defined by the International Astronomical Union (IAU is a Celestial body Orbiting the Sun that is massive enough to be rounded

Since the year 2000, several Trans-Neptunian objects have been discovered that lie in size between Mercury and Ceres, which arguably strengthens the case for a special classification such as mesoplanet. A trans-Neptunian object (TNO is any object in the Solar system that Orbits the sun at a greater distance on average than Neptune.

See also