Editing Definition of planet (section)

== Notes ==
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<li>{{Note label|B|b|none}} Defined as the region occupied by two bodies whose orbits cross a common distance from the Sun, if their orbital periods differ less than an order of magnitude. In other words, if two bodies occupy the same distance from the Sun at one point in their orbits, and those orbits are of similar size, rather than, as a [[comet]]'s would be, extending for several times the other's distance, then they are in the same orbital zone.<ref>{{cite journal| title= What is a Planet?| first=Steven| last=Soter| date=August 16, 2006| doi= 10.1086/508861| journal= The Astronomical Journal| volume= 132| issue= 6| pages= 2513–2519|arxiv=astro-ph/0608359|bibcode = 2006AJ....132.2513S | s2cid=14676169}} submitted to The Astronomical Journal, August 16, 2006</ref></li>
<li>{{Note label|C|c|none}}In 2002, in collaboration with dynamicist Harold Levison, Stern wrote, "we define an ''überplanet'' as a planetary body in orbit around a [[star]] that is dynamically important enough to have cleared its neighboring planetesimals ... And we define an ''unterplanet'' as one that has not been able to do so," and then a few paragraphs later, "our [[Solar System]] clearly contains 8 überplanets and a far larger number of unterplanets, the largest of which are [[Pluto]] and [[Ceres (dwarf planet)|Ceres]]."<ref name="Stern 2002">{{cite journal | last=Stern | first=S. Alan |author2=Levison, Harold F. | year=2002 | title=Regarding the criteria for planethood and proposed planetary classification schemes | url=http://www.boulder.swri.edu/~hal/PDF/planet_def.pdf | journal=Highlights of Astronomy| volume=12 | pages=205–213, as presented at the XXIVth General Assembly of the IAU–2000 [Manchester, UK, August 7–18, 2000]|bibcode = 2002HiA....12..205S | doi=10.1017/S1539299600013289 | doi-access=free }}</ref> While this may appear to contradict Stern's objections, Stern noted in an interview with Smithsonian Air and Space that, unlike the IAU's definition, his definition still allows unterplanets to be planets: "I do think from a dynamical standpoint, there are planets that really matter in the architecture of the solar system, and those that don't. They're both planets. Just as you can have wet and dry planets, or life-bearing and non-life-bearing planets, you can have dynamically important planets and dynamically unimportant planets."<ref name=smithsonian /></li>
<li>{{Note label|D|d|none}}The density of an object is a rough guide to its composition: the lower the density, the higher the fraction of ices, and the lower the fraction of rock. The denser objects, Vesta and Juno, are composed almost entirely of rock with very little ice, and have a density close to the [[Moon]]'s, while the less dense, such as Proteus and Enceladus, are composed mainly of ice.<ref>{{cite journal | year=1997 |author1=Righter, Kevin |author2=Drake, Michael J. | title=A magma ocean on Vesta: Core formation and petrogenesis of eucrites and diogenites | bibcode=1997M&PS...32..929R | doi=10.1111/j.1945-5100.1997.tb01582.x | journal=Meteoritics & Planetary Science | volume=32 | issue=6 | pages=929–944|s2cid=128684062 | doi-access=free }}</ref><ref>{{cite web |year=2003 |author1=Johanna Torppa |author2=Mikko Kaasalainen |author3=Tadeusz Michałowski |author4=Tomasz Kwiatkowski |author5=Agnieszka Kryszczyńska |author6=Peter Denchev |author7=Richard Kowalski |title=Shapes and rotational properties of thirty asteroids from photometric data |work=Astronomical Observatory, Adam Mickiewicz University |url=http://www.rni.helsinki.fi/~mjk/thirty.pdf |access-date=May 25, 2006 |archive-date=November 6, 2015 |archive-url=https://web.archive.org/web/20151106103549/http://www.rni.helsinki.fi/~mjk/thirty.pdf |url-status=dead }}</ref></li></ol>
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