Editing Solar wind (section)

===Observations from Earth===
The existence of particles flowing outward from the [[Sun]] to the [[Earth]] was first suggested by British astronomer [[Richard Christopher Carrington|Richard C. Carrington]]. In 1859, Carrington and [[Richard Hodgson (publisher)|Richard Hodgson]] independently made the first observations of what would later be called a [[solar flare]]. This is a sudden, localised increase in brightness on the solar disc, which is now known<ref>{{Cite journal|last1=Cliver|first1=Edward W.|last2=Dietrich|first2=William F.|date=2013-01-01|title=The 1859 space weather event revisited: limits of extreme activity|journal=Journal of Space Weather and Space Climate|language=en|volume=3|pages=A31|doi=10.1051/swsc/2013053|issn=2115-7251|bibcode = 2013JSWSC...3A..31C |doi-access=free}}</ref> to often occur in conjunction with an episodic ejection of material and magnetic flux from the Sun's atmosphere, known as a [[coronal mass ejection]]. The following day, a [[September 1859 geomagnetic storm|powerful geomagnetic storm]] was observed, and Carrington suspected that there might be a connection; the [[geomagnetic storm]] is now attributed to the arrival of the coronal mass ejection in near-Earth space and its subsequent interaction with the Earth's [[magnetosphere]]. Irish academic [[George Francis FitzGerald|George FitzGerald]] later suggested that matter was being regularly accelerated away from the Sun, reaching the Earth after several days.<ref name=meyer-vernet>{{cite book
 | first=Nicole | last=Meyer-Vernet | date=2007
 | title=Basics of the Solar Wind
 | publisher=Cambridge University Press
 | isbn=978-0-521-81420-1 }}</ref>

[[Image:Birkeland-anode-globe-fig259.jpg|thumb|upright=1.15|Laboratory simulation of the magnetosphere's influence on the solar wind; these aurora-like [[Birkeland current]]s were created in a [[terrella]], a magnetised anode globe in an evacuated chamber.]]

In 1910, British astrophysicist [[Arthur Eddington]] essentially suggested the existence of the solar wind, without naming it, in a footnote to an article on [[Comet Morehouse]].<ref name=durham>{{cite news
| first=Ian T. | last=Durham | date=2006
| title=Rethinking the History of Solar Wind Studies: Eddington's Analysis of Comet Morehouse
| url=http://rsnr.royalsocietypublishing.org/content/60/3/261.abstract
| journal=Notes and Records of the Royal Society | volume=60 | pages=261–270}}</ref> Eddington's proposition was never fully embraced, even though he had also made a similar suggestion at a [[Royal Institution]] address the previous year, in which he had postulated that the ejected material consisted of electrons, whereas in his study of Comet Morehouse he had supposed them to be [[ion]]s.<ref name=durham/>

The idea that the ejected material consisted of both ions and electrons was first suggested by Norwegian scientist [[Kristian Birkeland]].<ref>{{cite book |title=Kristian Birkeland: The First Space Scientist |first1=Alv |last1=Egeland |first2=William J. |last2=Burke |publisher=Springer, Dordrecht, The Netherlands |page=[https://archive.org/details/kristianbirkelan0000egel/page/80 80] |year=2005 |url=https://archive.org/details/kristianbirkelan0000egel|url-access=registration |isbn=978-1-4020-3294-3}}</ref> His geomagnetic surveys showed that auroral activity was almost uninterrupted. As these displays and other geomagnetic activity were being produced by particles from the Sun, he concluded that the Earth was being continually bombarded by "rays of electric corpuscles emitted by the Sun".<ref name="meyer-vernet" /> He proposed in 1916 that, "From a physical point of view it is most probable that solar rays are neither exclusively negative nor positive rays, but of both kinds"; in other words, the solar wind consists of both negative electrons and positive ions.<ref>Kristian Birkeland, "Are the Solar Corpuscular Rays that penetrate the Earth's Atmosphere Negative or Positive Rays?" in ''Videnskapsselskapets Skrifter'', I Mat – Naturv. Klasse No.1, Christiania, 1916.</ref> Three years later, in 1919, British physicist [[Frederick Lindemann, 1st Viscount Cherwell|Frederick Lindemann]] also suggested that the Sun ejects particles of both polarities: protons as well as electrons.<ref>''Philosophical Magazine'', Series 6, Vol. 38, No. 228, December 1919, 674 (on the Solar Wind)</ref>

Around the 1930s, scientists had concluded that the temperature of the [[solar corona]] must be a million degrees [[Anders Celsius|Celsius]] because of the way it extended into space (as seen during a total [[solar eclipse]]). Later [[Spectroscopy|spectroscopic]] work confirmed this extraordinary temperature to be the case. In the mid-1950s, British mathematician [[Sydney Chapman (mathematician)|Sydney Chapman]] calculated the properties of a gas at such a temperature and determined that the corona being such a superb conductor of heat, it must extend way out into space, beyond the orbit of Earth. Also in the 1950s, German astronomer [[Ludwig Biermann]] became interested in the fact that the tail of a [[comet]] always points away from the Sun, regardless of the direction in which the comet is travelling. Biermann postulated that this happens because the Sun emits a steady stream of particles that pushes the comet's tail away.<ref>{{cite journal |author=Ludwig Biermann |title=Kometenschweife und solare Korpuskularstrahlung |journal=Zeitschrift für Astrophysik |volume=29 |pages=274 |date=1951|bibcode = 1951ZA.....29..274B }}</ref> German astronomer [[Paul Oswald Ahnert|Paul Ahnert]] is credited (by Wilfried Schröder) as being the first to relate solar wind to the direction of a comet's tail based on observations of the comet Whipple–Fedke (1942g).<ref>{{cite journal|last=Schröder |first=Wilfried |title=Who first discovered the solar wind? |date=1 December 2008 |journal=Acta Geodaetica et Geophysica Hungarica |volume=43 |issue=4 |pages=471–472 |doi=10.1556/AGeod.43.2008.4.8|bibcode=2008AGGH...43..471S |s2cid=130425794 }}</ref>

American astrophysicist [[Eugene Parker]] realised that heat flowing from the Sun in Chapman's model, and the comet tail blowing away from the Sun in Biermann's hypothesis, had to be the result of the same phenomenon which he termed the "solar wind".<ref>{{cite web|title=THE SOLAR WIND AND MAGNETOSPHERIC DYNAMICS|author=Christopher T. Russell|work=Institute of Geophysics and Planetary Physics University of California, Los Angeles|url=http://www-ssc.igpp.ucla.edu/personnel/russell/papers/solwind_magsphere/|access-date=2007-02-07|archive-date=August 13, 2018|archive-url=https://web.archive.org/web/20180813043542/http://www-ssc.igpp.ucla.edu/personnel/russell/papers/solwind_magsphere/|url-status=dead}}</ref><ref>{{cite news | last=Roach | first=John | title=Astrophysicist Recognized for Discovery of Solar Wind | work=National Geographic Society | date=August 27, 2003 | url=http://news.nationalgeographic.com/news/2003/08/0827_030827_kyotoprizeparker.html | access-date=2006-06-13 |archive-url=https://web.archive.org/web/20030830010454/http://news.nationalgeographic.com/news/2003/08/0827_030827_kyotoprizeparker.html |archive-date=August 30, 2003 |url-status=dead}}</ref> In 1957, Parker showed that although the Sun's corona is strongly attracted by solar gravity, it is such a good conductor of heat that it is still very hot at large distances from the Sun. As solar gravity weakens with increasing distance from the Sun, the outer coronal atmosphere is able to escape [[Supersonic speed|supersonically]] into interstellar space. Parker was also the first person to notice that the weakening influence of the Sun's gravity has the same effect on [[hydrodynamic]] flow as a [[de Laval nozzle]], inciting a transition from [[Speed of sound|subsonic]] to supersonic flow.<ref name="Parker 1958">{{cite journal |last=Parker |first=Eugene N. |bibcode=1958ApJ...128..664P |title=Dynamics of the Interplanetary Gas and Magnetic Fields |journal=The Astrophysical Journal |volume=128 |pages=664–676 |date=November 1958 |doi=10.1086/146579}}</ref> There was strong opposition to Parker's hypothesis on the solar wind; the paper he submitted to ''[[The Astrophysical Journal]]'' in 1958<ref name="Parker 1958" /> was rejected by two reviewers, before being accepted by the editor [[Subrahmanyan Chandrasekhar]].<ref>{{Citation | title = The martial art of scientific publication | year = 1997 | last1 = Parker | first1 = E. N. | journal = [[Eos (magazine)|EOS Transactions]] | volume = 78 | issue = 37 | pages = 391–395 | doi = 10.1029/97EO00251 | bibcode = 1997EOSTr..78..391P}}</ref><ref>{{Cite web |date=2018-07-31 |title=NASA mission honors pioneering UChicago physicist {{!}} University of Chicago News |url=https://news.uchicago.edu/story/nasa-mission-honors-pioneering-uchicago-physicist |access-date=2024-04-30 |website=news.uchicago.edu |language=en}}</ref>