Editing Zodiacal light (section)

== Origin ==

[[File:Moonlight and Zodiacal Light Over La Silla Observatory.jpg|thumb|Moonlight and zodiacal light over [[La Silla Observatory]]<ref>{{cite news|title=Moonlight and Zodiacal Light Over La Silla|url=http://www.eso.org/public/images/potw1325a/|access-date=21 July 2013|newspaper=ESO Picture of the Week}}</ref> ]]

The source of the dust has been long debated. Until recently, it was thought that the dust originated from the tails of active [[comet]]s and from collisions between [[asteroid]]s in the [[asteroid belt]].<ref>{{Cite journal|bibcode=2006DPS....38.4101E 
|title= Towards a Global Model of the Zodiacal Cloud 
|journal =Bulletin of the American Astronomical Society |volume=38 |page=557 
|author=Espy, Ashley J. |author2=Dermott, S. |author3=Kehoe, T. J. 
|date=September 2006}}</ref> Many of our meteor showers have no known active comet parent bodies.  Over 85 percent of the dust is attributed to occasional fragmentations of Jupiter-family comets that are nearly [[Extinct comet|dormant]].<ref>{{cite journal|title= Cometary Origin of the Zodiacal Cloud and Carbonaceous Micrometeorites. Implications for hot debris disks |journal=Astrophysical Journal |date=April 20, 2010 |volume=713 |issue= 2 |doi=10.1088/0004-637x/713/2/816 |bibcode=2010ApJ...713..816N |pages=816–836
|arxiv = 0909.4322 |last1= Nesvorný |first1= David |last2= Jenniskens |first2= Peter |last3= Levison |first3= Harold F. |last4= Bottke |first4= William F. |last5= Vokrouhlický |first5= David |last6= Gounelle |first6= Matthieu |s2cid=18865066 }}</ref> Jupiter-family comets have orbital periods of less than 20 years<ref>{{cite book|last=Jenniskens|first=Petrus Matheus Marie|title=Meteor showers and their parent comets|date=2006|publisher=[[Cambridge University Press]]|isbn=978-0-521-85349-1|pages=108}}</ref> and are considered dormant when not actively outgassing, but may do so in the future.<ref>{{cite web|title=Comet or Asteroid? Big Space Rock Has Identity Crisis|url=http://www.space.com/9700-comet-asteroid-big-space-rock-identity-crisis.html|publisher=SPACE.com|access-date=23 May 2011|author=SPACE.com Staff|date=6 January 2011|quote=Dormant comets retain some subsurface volatiles and may start outgassing once again as they near the sun.}}</ref> The first fully dynamical model of the zodiacal cloud demonstrated that only if the dust was released in orbits that approach Jupiter, is it stirred up enough to explain the thickness of the zodiacal dust cloud. The dust in meteoroid streams is much larger, 300 to 10,000 [[micrometre]]s in diameter, and falls apart into smaller zodiacal dust grains over time.
[[File:Romantic Sunset over the VLT.jpg|thumb|upright|Colorful center of the [[Milky Way]] and the zodiacal light above the [[Very Large Telescope]]<ref>{{cite web|title=Romantic Sunset over the VLT|url=http://www.eso.org/public/images/potw1516a/|website=www.eso.org|publisher=[[European Southern Observatory]]|access-date=21 April 2015}}</ref>]]
The [[Poynting–Robertson effect]] forces the dust into more circular (but still elongated) orbits, while spiralling slowly into the Sun. Hence a continuous source of new particles is needed to maintain the zodiacal cloud. [[Comet]]ary dust and dust generated by collisions among the [[asteroid]]s are believed to be mostly responsible for the maintenance of the dust cloud producing the zodiacal light and the [[gegenschein]].

Particles can be reduced in size by collisions or by space weathering. When ground down to sizes less than 10 micrometres, the grains are removed from the inner Solar System by solar radiation pressure. The dust is then replenished by the infall from comets. Zodiacal dust around nearby stars is called [[exozodiacal dust]]; it is a potentially important source of noise in attempts to directly image [[extrasolar planets]]. It has been pointed out that this exozodiacal dust, or hot debris disks, can be an indicator of planets, as planets tend to scatter the comets to the inner Solar System.

In 2015, new results from the secondary ion dust spectrometer COSIMA on board the [[Rosetta (spacecraft)|''ESA/Rosetta'']] orbiter confirmed that the parent bodies of interplanetary dust are most probably Jupiter-family comets such as comet [[67P/Churyumov–Gerasimenko]].<ref>{{cite journal|author=Rita Schulz |title=Comet 67P/Churyumov-Gerasimenko sheds dust coat accumulated over the past four years |journal= Nature|date=12 February 2015|issue=7538 |pages=216–218 |doi=10.1038/nature14159 |volume=518|bibcode = 2015Natur.518..216S |display-authors=etal |pmid=25624103|s2cid=205242328 }}</ref> Data from the [[Juno (spacecraft)|Juno]] mission indicate that the dust close to Earth has a local origin in the inner Solar System, best fitting the planet Mars as a source.<ref>[https://www.spacedaily.com/reports/Juno_data_shatter_ideas_about_origin_of_Zodiacal_Light_999.html Space Daily: Juno data shatter ideas about origin of Zodiacal Light]</ref>