Editing Exoplanet (section)

=== Candidate discoveries ===
As of January 2020, NASA's [[Kepler (spacecraft)|''Kepler'']] and [[Transiting Exoplanet Survey Satellite|TESS]] missions had identified 4374 planetary candidates yet to be confirmed,<ref>{{Cite web|url=https://exoplanetarchive.ipac.caltech.edu/docs/counts_detail.html|title=Exoplanet and Candidate Statistics|publisher=NASA Exoplanet Archive, California Institute of Technology|access-date=2020-01-17}}</ref> several of them being nearly Earth-sized and located in the habitable zone, some around Sun-like stars.<ref name="keplersite">{{cite web |author=Colen |first=Jerry |date=4 November 2013 |title=Kepler |url=http://www.nasa.gov/mission_pages/kepler/main/index.html |archive-url=https://web.archive.org/web/20131105082102/http://www.nasa.gov/mission_pages/kepler/main/index.html |archive-date=5 November 2013 |access-date=4 November 2013 |website=nasa.gov |publisher=NASA}}</ref><ref name="usher">{{cite web |last1=Harrington |first1=J. D. |last2=Johnson |first2=M. |date=4 November 2013 |title=NASA Kepler Results Usher in a New Era of Astronomy |url=http://www.nasa.gov/press/2013/november/nasa-kepler-results-usher-in-a-new-era-of-astronomy/}}</ref><ref name="NASA-ExoplanetArch">{{cite web|title=NASA's Exoplanet Archive KOI table|url=http://exoplanetarchive.ipac.caltech.edu/cgi-bin/ExoTables/nph-exotbls?dataset=cumulative|publisher=NASA|access-date=28 February 2014|archive-url=https://archive.today/20140226203336/http://exoplanetarchive.ipac.caltech.edu/cgi-bin/ExoTables/nph-exotbls?dataset=cumulative|archive-date=26 February 2014|url-status=dead}}</ref>
{{multiple image
| header            = Exoplanet populations – June 2017<!--
  --><ref name="SP-20170619">{{cite web |last=Lewin |first=Sarah |title=NASA's Kepler Space Telescope Finds Hundreds of New Exoplanets, Boosts Total to 4,034 |url=https://www.space.com/37242-nasa-kepler-alien-planets-habitable-worlds-catalog.html |date=19 June 2017 |work=[[NASA]] |access-date=19 June 2017}}</ref><!--
  --><ref name="NYT-20170619">{{cite news |last=Overbye |first=Dennis |author-link=Dennis Overbye |title=Earth-Size Planets Among Final Tally of NASA's Kepler Telescope |url=https://www.nytimes.com/2017/06/19/science/kepler-planets-earth-like-census.html |archive-url=https://ghostarchive.org/archive/20220101/https://www.nytimes.com/2017/06/19/science/kepler-planets-earth-like-census.html |archive-date=2022-01-01 |url-access=limited |date=19 June 2017 |work=The New York Times}}{{cbignore}}</ref>
| align             = center
| caption_align     = center
| direction         = horizontal
| width             = 333
| image1            = ExoplanetPopulations-20170616.png
| alt1              = 
| caption1          = Exoplanet populations; colors indicate detection method
| image2            = SmallPlanetsComeInTwoSizes-20170619.png
| alt2              = 
| caption2          = Small planets come in two sizes
| image3            = KeplerHabitableZonePlanets-20170616.png
| alt3              = 
| caption3          = Kepler habitable zone planets
}}

In September 2020, astronomers reported evidence, for the first time, of an [[extragalactic planet]], [[M51-ULS-1b]], detected by eclipsing a bright [[Astrophysical X-ray source|X-ray source]] (XRS), in the [[Whirlpool Galaxy]] (M51a).<ref name="NS-20200923">{{cite news |last=Crane |first=Leah |title=Astronomers may have found the first planet in another galaxy |url=https://www.newscientist.com/article/2255431-astronomers-may-have-found-the-first-planet-in-another-galaxy/ |date=23 September 2020 |work=[[New Scientist]] |access-date=25 September 2020 }}</ref><ref name="ARX-20200918">{{cite arXiv |author=Di Stafano, R. |display-authors=et al. |title=M51-ULS-1b: The First Candidate for a Planet in an External Galaxy |date=18 September 2020 |class=astro-ph.HE |eprint=2009.08987 }}</ref>