What is Heliosphere?
The '''heliosphere''' is the [[magnetosphere]], [[stellar wind]] bubble and outermost atmospheric layer of the [[Sun]]. [[Image:72408main ACD97-0036-1.jpg|thumb|right|400px|Diagram of features of the heliosphere. Based on preliminary results from the [[Interstellar Boundary Explorer]].]] The '''heliosphere''' is the cavity made by the Sun in the [[interstellar medium]]. Almost all of the material in the heliosphere comes from the [[Sun]] itself. For the first ten billion kilometres of its radius, the solar wind travels at over a million kilometres per hour.<ref name=speed>{{cite web|author=Dr. David H. Hathaway|date=January 18, 2007|title=The Solar Wind|publisher=NASA|url=http://solarscience.msfc.nasa.gov/SolarWind.shtml|accessdate=2007-12-11|archive-date=2015-08-13|archive-url=https://web.archive.org/web/20150813081520/http://solarscience.msfc.nasa.gov/SolarWind.shtml|url-status=dead}}</ref><ref>{{cite news | first=Robert Roy | last=Britt | title=A Glowing Discovery at the Forefront of Our Plunge Through Space | publisher=SPACE.com | date=March 15, 2000 | url=http://www.space.com/scienceastronomy/solarsystem/heliosphere_shock_000315.html | accessdate=2006-05-24 | archive-date=2001-01-11 | archive-url=https://web.archive.org/web/20010111053400/http://www.space.com/scienceastronomy/solarsystem/heliosphere_shock_000315.html | url-status=dead }}</ref> It slows down before finally stopping altogether. The point where the solar wind slows down is the '''termination shock'''; the point where the interstellar medium and solar wind pressures balance is called the '''heliopause'''; the point where the interstellar medium, travelling in the opposite direction, slows down as it collides with the heliosphere is the '''bow shock'''. ==Solar wind== {{main|Solar wind}} The solar wind is made of particles. They are charged ([[ion]]ized) atoms from the solar [[corona]], and fields, in particular [[magnetic field]]s. As the Sun [[rotation|rotate]]s once in about 27 days, the magnetic field transported by the [[solar wind]