View source for Solar conjunction

{{Short description|Solar system object is on the opposite side of the Sun from the Earth}}
[[File:Solar Conjunction.jpg|250px|thumb|right|Solar conjunction between Earth and Mars]]
'''Solar conjunction''' generally occurs when a [[planet]] or other [[Solar System]] object is on the opposite side of the [[Sun]] from the [[Earth]].  From an Earth reference, the Sun will pass between the Earth and the object. Communication with any [[spacecraft]] in solar conjunction will be severely limited due to the Sun's interference on radio transmissions from the spacecraft.<ref name=lat20130405>
{{cite news |last=Khan|first=Amina |title=NASA Mars Curiosity rover gets to work on 'spring break' chores|url=https://www.latimes.com/news/science/sciencenow/la-sci-sn-mars-curiosity-working-conjunction-spring-break-20130405,0,2992673.story |accessdate=2013-04-07 |newspaper=Los Angeles Times |date=2013-04-05}}</ref>

The term can also refer to the passage of the line of sight to an interior planet ([[Mercury (planet)|Mercury]] or [[Venus]]) or comet being very close to the solar disk. If the planet passes directly in front of the Sun, a [[Astronomical transit|solar transit]] occurs.

==Spacecraft-related issues==
There is also a risk that an antenna equipped with auto-tracking will begin following the Sun's movements instead of the satellite once they are no longer inline with each other. This is because the Sun acts as a large electromagnetic noise generator which creates a signal much stronger than the satellite's tracking signal.{{Citation needed|reason=UNdue weight - this would only make sense if using a dumb max-signal tracker. May not be valid with modern systems|date=April 2013}}
One example of limitations caused by the solar conjunction occurred when the [[NASA]]-[[JPL]] team put the [[Curiosity rover]] on [[Mars|Mars']] surface in [[autonomous]] operation mode for 25 days during the conjunction. In autonomous mode [[Curiosity (rover)|Curiosity]] suspends all movements and active science operations but retains communication-independent experiments (e.g. record atmospheric and radiation data).{{cn|date=November 2021}} A more recent example occurred with the Mars rover [[Perseverance (rover)|Perseverance]] in October 2021.<ref>{{cite web|url=https://www.space.com/mars-rover-perseverance-back-to-work-photos|title=Perseverance rover snaps first Mars photos after communications blackout. They're stunning|author=Mike Wall|work=Space.com|date=27 October 2021}}</ref>

==See also==
* [[Conjunction (astronomy and astrology)]]
* [[List of conjunctions (astronomy)]]
* [[Opposition (astronomy)]]

==References==
{{reflist}}

{{DEFAULTSORT:Solar Conjunction}}
[[Category:Astrological aspects]]
[[Category:Conjunctions (astronomy and astrology)]]
[[Category:Satellite broadcasting]]
[[Category:Spaceflight concepts]]


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