Editing Solar System (section)

=== Edge of the heliosphere ===
[[File:Magnetosphere Levels.jpg|thumb|Diagram of the Sun's magnetosphere and helioshealth]]

{{Anchor|Heliopause}}The Sun's [[stellar-wind bubble]], the [[heliosphere]], a region of space dominated by the Sun, has its boundary at the ''termination shock''. Based on the Sun's [[peculiar motion]] relative to the [[local standard of rest]], this boundary is roughly 80–100&nbsp;AU from the Sun upwind of the interstellar medium and roughly 200&nbsp;AU from the Sun downwind.<ref name="fahr">{{Cite journal |last1=Fahr |first1=H. J. |last2=Kausch |first2=T. |last3=Scherer |first3=H. |date=2000 |title=A 5-fluid hydrodynamic approach to model the Solar System-interstellar medium interaction |url=http://aa.springer.de/papers/0357001/2300268.pdf |url-status=dead |journal=[[Astronomy & Astrophysics]] |volume=357 |page=268 |bibcode=2000A&A...357..268F |archive-url=https://web.archive.org/web/20170808135422/http://aa.springer.de/papers/0357001/2300268.pdf |archive-date=8 August 2017 |access-date=24 August 2008}} See Figures 1 and 2.</ref> Here the solar wind collides with the interstellar medium<ref>{{Cite web |last=Hatfield |first=Miles |date=3 June 2021 |title=The Heliopedia |url=http://www.nasa.gov/mission_pages/sunearth/the-heliopedia |url-status=live |archive-url=https://web.archive.org/web/20220325142928/https://www.nasa.gov/mission_pages/sunearth/the-heliopedia |archive-date=25 March 2022 |access-date=29 March 2022 |website=NASA}}</ref> and dramatically slows, condenses and becomes more turbulent, forming a great oval structure known as the [[heliosheath]].<ref name="fahr" />

The heliosheath has been theorized to look and behave very much like a comet's tail, extending outward for a further 40&nbsp;AU on the upwind side but tailing many times that distance downwind to possibly several thousands of AU.<ref name="n092">{{cite journal | last1=Brandt | first1=P. C. | last2=Provornikova | first2=E. | last3=Bale | first3=S. D. | last4=Cocoros | first4=A. | last5=DeMajistre | first5=R. | last6=Dialynas | first6=K. | last7=Elliott | first7=H. A. | last8=Eriksson | first8=S. | last9=Fields | first9=B. | last10=Galli | first10=A. | last11=Hill | first11=M. E. | last12=Horanyi | first12=M. | last13=Horbury | first13=T. | last14=Hunziker | first14=S. | last15=Kollmann | first15=P. | last16=Kinnison | first16=J. | last17=Fountain | first17=G. | last18=Krimigis | first18=S. M. | last19=Kurth | first19=W. S. | last20=Linsky | first20=J. | last21=Lisse | first21=C. M. | last22=Mandt | first22=K. E. | last23=Magnes | first23=W. | last24=McNutt | first24=R. L. | last25=Miller | first25=J. | last26=Moebius | first26=E. | last27=Mostafavi | first27=P. | last28=Opher | first28=M. | last29=Paxton | first29=L. | last30=Plaschke | first30=F. | last31=Poppe | first31=A. R. | last32=Roelof | first32=E. C. | last33=Runyon | first33=K. | last34=Redfield | first34=S. | last35=Schwadron | first35=N. | last36=Sterken | first36=V. | last37=Swaczyna | first37=P. | last38=Szalay | first38=J. | last39=Turner | first39=D. | last40=Vannier | first40=H. | last41=Wimmer-Schweingruber | first41=R. | last42=Wurz | first42=P. | last43=Zirnstein | first43=E. J. | title=Future Exploration of the Outer Heliosphere and Very Local Interstellar Medium by Interstellar Probe | journal=Space Science Reviews | volume=219 | issue=2 | date=2023 | issn=0038-6308 | pmid=36874191 | pmc=9974711 | doi=10.1007/s11214-022-00943-x | page=18| bibcode=2023SSRv..219...18B }}</ref><ref>{{Cite journal |last1=Baranov |first1=V. B. |last2=Malama |first2=Yu. G. |date=1993 |title=Model of the solar wind interaction with the local interstellar medium: Numerical solution of self-consistent problem |url=http://doi.wiley.com/10.1029/93JA01171 |journal=Journal of Geophysical Research |language=en |volume=98 |issue=A9 |page=15157 |bibcode=1993JGR....9815157B |doi=10.1029/93JA01171 |issn=0148-0227 |access-date=9 April 2022 |archive-date=20 April 2022 |archive-url=https://web.archive.org/web/20220420161220/https://onlinelibrary.wiley.com/resolve/doi?DOI=10.1029%2F93JA01171 |url-status=live }}</ref> Evidence from the ''[[Cassini (spacecraft)|Cassini]]'' and [[Interstellar Boundary Explorer]] spacecraft has suggested that it is forced into a bubble shape by the constraining action of the interstellar magnetic field,<ref>{{Cite web |date=19 November 2009 |title=Cassini's Big Sky: The View from the Center of Our Solar System |url=https://www.jpl.nasa.gov/news/cassinis-big-sky-the-view-from-the-center-of-our-solar-system |url-status=live |archive-url=https://web.archive.org/web/20220409213721/https://www.jpl.nasa.gov/news/cassinis-big-sky-the-view-from-the-center-of-our-solar-system |archive-date=9 April 2022 |access-date=9 April 2022 |website=Jet Propulsion Laboratory}}</ref><ref>{{Cite journal |last1=Kornbleuth |first1=M. |last2=Opher |first2=M. |last3=Baliukin |first3=I. |last4=Gkioulidou |first4=M. |last5=Richardson |first5=J. D. |last6=Zank |first6=G. P. |last7=Michael |first7=A. T. |last8=Tóth |first8=G. |last9=Tenishev |first9=V. |last10=Izmodenov |first10=V. |last11=Alexashov |first11=D. |date=1 December 2021 |title=The Development of a Split-tail Heliosphere and the Role of Non-ideal Processes: A Comparison of the BU and Moscow Models |journal=[[The Astrophysical Journal]] |volume=923 |issue=2 |page=179 |arxiv=2110.13962 |bibcode=2021ApJ...923..179K |doi=10.3847/1538-4357/ac2fa6 |issn=0004-637X |s2cid=239998560 |doi-access=free}}</ref> but the actual shape remains unknown.<ref>{{Cite journal |last1=Reisenfeld |first1=Daniel B. |last2=Bzowski |first2=Maciej |last3=Funsten |first3=Herbert O. |last4=Heerikhuisen |first4=Jacob |last5=Janzen |first5=Paul H. |last6=Kubiak |first6=Marzena A. |last7=McComas |first7=David J. |last8=Schwadron |first8=Nathan A. |last9=Sokół |first9=Justyna M. |last10=Zimorino |first10=Alex |last11=Zirnstein |first11=Eric J. |date=1 June 2021 |title=A Three-dimensional Map of the Heliosphere from IBEX |journal=[[The Astrophysical Journal Supplement Series]] |volume=254 |issue=2 |page=40 |bibcode=2021ApJS..254...40R |doi=10.3847/1538-4365/abf658 |issn=0067-0049 |osti=1890983 |s2cid=235400678 |doi-access=free}}</ref>

The shape and form of the outer edge of the heliosphere is likely affected by the [[fluid dynamics]] of interactions with the interstellar medium as well as [[solar magnetic field]]s prevailing to the south, e.g. it is bluntly shaped with the northern hemisphere extending 9&nbsp;AU farther than the southern hemisphere.<ref name="fahr" /> The heliopause is considered the beginning of the interstellar medium.<ref name="Voyager" /> Beyond the heliopause, at around 230&nbsp;AU, lies the [[bow shock]]: a plasma "wake" left by the Sun as it travels through the Milky Way.<ref>{{Cite APOD|date=24 June 2002|title=The Sun's Heliosphere & Heliopause|access-date=23 June 2006}}</ref> Large objects outside the heliopause remain gravitationally bound to the Sun, but the flow of matter in the interstellar medium homogenizes the distribution of micro-scale objects.<ref name="Voyager" />