Editing Exoplanet (section)

==== Earth-size planets ====
{{See also|Earth analog}}
* In November 2013, it was estimated that 22±8% of Sun-like<ref group="lower-alpha" name="footnoteA"/> stars in the Milky Way galaxy may have an Earth-sized<ref group="lower-alpha" name="footnoteB"/> planet in the habitable<ref group=lower-alpha name=footnoteC/> zone.<ref name="ucb1in5" /><ref name="earthsunhzprev" /> Assuming 200 billion stars in the Milky Way,<ref group="lower-alpha" name="footnoteD"/> that would be 11 billion potentially habitable Earths, rising to 40 billion if [[red dwarf]]s are included.<ref name="LATimes-20131104"/>
* [[Kepler-186f]], a 1.2-Earth-radius planet in the habitable zone of a [[red dwarf]], was reported in April 2014.
*Proxima Centauri b, a planet in the habitable zone of [[Proxima Centauri]], the nearest known star to the solar system with an estimated minimum mass of 1.27 times the mass of the Earth.
* In February 2013, researchers speculated that up to 6% of small red dwarfs may have Earth-size planets. This suggests that the closest one to the Solar System could be 13 light-years away. The estimated distance increases to 21 light-years when a 95% [[confidence interval]] is used.<ref name="howell-2013">{{cite news | url=http://www.space.com/19667-closest-alien-earth-exoplanets.html | title=Closest 'Alien Earth' May Be 13 Light-Years Away | work=Space.com | date=6 February 2013 | agency=TechMediaNetwork | access-date=7 February 2013 | author=Howell, Elizabeth}}</ref> In March 2013, a revised estimate gave an occurrence rate of 50% for Earth-size planets in the habitable zone of red dwarfs.<ref name="Habitable Exoplanet Re-estimate">{{cite journal| last=Kopparapu |first=Ravi Kumar |title=A revised estimate of the occurrence rate of terrestrial planets in the habitable zones around Kepler M-dwarfs |journal=[[The Astrophysical Journal Letters]] |date=March 2013 |arxiv=1303.2649 |bibcode=2013ApJ...767L...8K|volume=767|issue=1 |pages=L8| doi=10.1088/2041-8205/767/1/L8|s2cid=119103101 }}</ref>
* At 1.63 times Earth's radius [[Kepler-452b]] is the first discovered near-Earth-size planet in the [[Circumstellar habitable zone|"habitable zone"]] around a [[G star|G2-type]] [[Sun-like]] star (July 2015).<ref>{{cite web| title = NASA's Kepler Mission Discovers Bigger, Older Cousin to Earth| url = http://www.nasa.gov/press-release/nasa-kepler-mission-discovers-bigger-older-cousin-to-earth |access-date = 2015-07-23| date = 2015-07-23 }}</ref>
{| class="wikitable" style="margin:0.5em auto; width:450px; align=right"
! [[Exoplanet|Notable Exoplanets]] – [[Kepler (spacecraft)|Kepler Space Telescope]] 
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| style="font-size:88%" | [[File:PIA19827-Kepler-SmallPlanets-HabitableZone-20150723.jpg|600px]]
{{center|Comparison of small planets found by ''[[Kepler (spacecraft)|Kepler]]'' in the [[habitable zone]] of their host stars.}}
|}