Editing Proxima Centauri (section)

===Habitability===
{{See also|Habitability of red dwarf systems}}
{{stack|[[File:Proxima Centauri and its planet compared to the Solar System.jpg|thumb|upright=1.2|Overview and comparison of the orbital distance of the [[habitable zone]]]]}}
Before the discovery of Proxima Centauri&nbsp;b, the TV documentary ''[[Extraterrestrial (TV documentary)#Episode 1: Aurelia|Alien Worlds]]'' hypothesized that a life-sustaining planet could exist in orbit around Proxima Centauri or other red dwarfs. Such a planet would lie within the habitable zone of Proxima Centauri, about {{convert|0.023|–|0.054|AU|e6km|abbr=unit}} from the star, and would have an orbital period of 3.6–14&nbsp;days.<ref>
{{cite conference
 |last1=Endl     |first1=M.      |last2=Kuerster |first2=M.
 |last3=Rouesnel |first3=F.      |last4=Els      |first4=S.
 |last5=Hatzes   |first5=A.P.    |last6=Cochran  |first6=W.D.
 |date=18–21 June 2002
 |title=Extrasolar terrestrial planets: Can we detect them already?
 |editor-first=Drake  |editor-last=Deming
 |conference=Scientific Frontiers in Research on Extrasolar Planets
 |pages=75–79
 |location=Washington, DC
 |arxiv=astro-ph/0208462 |bibcode=2003ASPC..294...75E
}}
</ref>
A planet orbiting within this zone may experience [[tidal locking]] to the star. If the orbital eccentricity of this hypothetical planet were low, Proxima Centauri would move little in the planet's sky, and most of the surface would experience either day or night perpetually. The presence of an atmosphere could serve to redistribute heat from the star-lit side to the far side of the planet.<ref name="tarter">{{cite journal |title=A reappraisal of the habitability of planets around M dwarf stars |journal=[[Astrobiology (journal)|Astrobiology]] |date=2007 |volume=7 |issue=1 |pages=30–65 |doi=10.1089/ast.2006.0124 |pmid=17407403 |bibcode=2007AsBio...7...30T |arxiv=astro-ph/0609799 | last1=Tarter | first1=Jill C. | last2=Mancinelli | first2=Rocco L. | last3=Aurnou | first3=Jonathan M. | last4=Backman | first4=Dana E. | last5=Basri | first5=Gibor S. | last6=Boss | first6=Alan P. | last7=Clarke | first7=Andrew | last8=Deming | first8=Drake|s2cid=10932355 }}</ref>

Proxima Centauri's [[Solar flare|flare]] outbursts could erode the atmosphere of any planet in its habitable zone, but the documentary's scientists thought that this obstacle could be overcome. [[Gibor Basri]] of the [[University of California, Berkeley]] argued: "No one [has] found any showstoppers to habitability." For example, one concern was that the torrents of charged particles from the star's flares could strip the atmosphere off any nearby planet. If the planet had a strong magnetic field, the field would deflect the particles from the atmosphere; even the slow rotation of a tidally locked planet that spins once for every time it orbits its star would be enough to generate a magnetic field, as long as part of the planet's interior remained molten.<ref>{{cite journal |last=Alpert |first=Mark |date=November 2005 |title=Red star rising |journal=Scientific American |volume=293 |issue=5 |pages=28 |doi=10.1038/scientificamerican1105-28 |pmid=16318021 |bibcode=2005SciAm.293e..28A}}</ref>

Other scientists, especially proponents of the [[Rare Earth hypothesis]],<ref>{{cite book |first1=Peter D. |last1=Ward |author-link=Peter Ward (paleontologist) |last2=Brownlee |first2=Donald |author-link2=Donald E. Brownlee |date=2000 |title=Rare Earth: why complex life is uncommon in the universe |publisher=[[Springer Publishing]] |isbn=978-0-387-98701-9}}</ref> disagree that red dwarfs can sustain life. Any exoplanet in this star's habitable zone would likely be tidally locked, resulting in a relatively weak planetary [[magnetic moment]], leading to strong atmospheric erosion by [[coronal mass ejection]]s from Proxima Centauri.<ref name="Khodachenko">{{cite journal |title=Coronal Mass Ejection (CME) activity of low mass M stars as an important factor for the habitability of terrestrial exoplanets. I. CME impact on expected magnetospheres of earth-like exoplanets in close-in habitable zones |journal=Astrobiology |date=2007 |volume=7 |issue=1 |pages=167–184 |doi=10.1089/ast.2006.0127 |pmid=17407406 |bibcode=2007AsBio...7..167K | last1=Khodachenko | first1=Maxim L. | last2=Lammer | first2=Helmut | last3=Grießmeier | first3=Jean-Mathias | last4=Leitner | first4=Martin | last5=Selsis | first5=Franck | last6=Eiroa | first6=Carlos | last7=Hanslmeier | first7=Arnold | last8=Biernat | first8=Helfried K. }}</ref> In December 2020, a candidate [[SETI]] radio signal [[BLC-1]] was announced as potentially coming from the star.<ref name="OCallaghan2000">{{Cite web
 | last=O'Callaghan | first=Jonathan | date=2020-12-18
 | title=Alien Hunters Discover Mysterious Radio Signal from Proxima Centauri
 | url=https://www.scientificamerican.com/article/alien-hunters-discover-mysterious-signal-from-proxima-centauri/
 | access-date=2020-12-19
 | website=Scientific American | language=en }}</ref> The signal was later determined to be human-made radio interference.<ref>{{cite journal
 | title=Mysterious 'alien beacon' was false alarm
 | first=Alexandra | last=Witze
 | journal=Nature | date=25 October 2021
 | volume=599 | issue=7883 | pages=20–21 | doi=10.1038/d41586-021-02931-7 | pmid=34697482
| bibcode=2021Natur.599...20W | s2cid=239887089 | doi-access=free }}</ref>