Editing Luna 3 (section)

{{short description|Soviet lunar probe launched in 1959}}
{{Use dmy dates|date=November 2017}}
{{Infobox spaceflight
| name               = Luna 3
| image              = Луна-3 (14562265547).jpg
| image_caption      = A 1:1 scale model at the [[Memorial Museum of Cosmonautics]] in Moscow
| mission_type       = Lunar flyby{{sfn|Siddiqi|2018|p=13}}
| operator           = Soviet space program|
| website            = 
| Harvard_designation = 1959 Theta 1<ref>{{cite web|url=https://space.skyrocket.de/doc_sdat/luna_e2a.htm|title=Luna Ye-2A|website=Gunter's Space Page|access-date=12 November 2019}}</ref>
| COSPAR_ID          = 1959-008A
| SATCAT             = 21
| mission_duration   = 18 days (launch day to last contact day)
| orbits_completed   = 14
| spacecraft         = [[Ye-2A]] No.1{{sfn|Siddiqi|2018|p=13}}
| manufacturer       = [[OKB-1]]
| dry_mass           = 
| launch_mass        = {{convert|278.5|kg|lb}}{{sfn|Siddiqi|2018|p=13}}
| power              = <!-- [[watt]]s -->
| launch_date        = {{start date text|4 October 1959, 00:43:40|timezone=yes}}&nbsp;UTC{{sfn|Siddiqi|2018|p=13}}
| launch_rocket      = [[Luna (rocket)|Luna]] 8K72 (No I1-8){{sfn|Siddiqi|2018|p=13}}
| launch_site        = [[Baikonur Cosmodrome|Baikonur]] [[Baikonur Cosmodrome Site 1|1/5]]{{sfn|Siddiqi|2018|p=13}}
| launch_contractor  = 
| last_contact       = {{end date text|22 October 1959}}<ref>{{cite web|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1959-008A|title=Luna 3|website=NASA Space Science Data Coordinated Archive|access-date=5 February 2020}}</ref>
| decay_date         = 29 April 1960
| orbit_epoch        = 5 October 1959<ref name="satcat">{{cite web|url=http://planet4589.org/space/log/satcat.txt|title=Satellite Catalog|first=Jonathan|last=McDowell|work=Jonathan's Space Page|access-date=14 December 2014}}</ref>
| orbit_reference    = [[Geocentric orbit|Geocentric]]
| orbit_regime       = [[Highly elliptical orbit|Highly elliptical]]<br/>([[Circumlunar trajectory|circumlunar]])
| orbit_periapsis    = {{convert|500|km|mi}}
| orbit_apoapsis     = {{convert|499999|km|mi}}
| orbit_inclination  = 55&nbsp;degrees
| orbit_period       = 359.38&nbsp;hours
| orbit_semimajor    = {{convert|256620.50|km|mi}}
| orbit_eccentricity = 0.97322501
| apsis              = gee
| programme          = '''[[Luna programme]]'''
| previous_mission   = [[Luna 2]]
| next_mission       = ''[[Luna E-3 No.1|Luna 1960A]]''
| interplanetary     = {{Infobox spaceflight/IP
   |type                = flyby
   |object              = the [[Moon]]
   |arrival_date        = 6 October 1959, 14:16&nbsp;UTC
   |distance            = {{convert|6200|km}}
 }}
}}
'''Luna 3''', or '''E-2A No.1''' ({{langx|ru|Луна 3|}}), was a [[Soviet Union|Soviet]] [[spacecraft]] launched in 1959 as part of the [[Luna programme]]. It was the first mission to photograph the [[far side of the Moon]] and the third Soviet space probe to be sent to the neighborhood of the [[Moon]].{{sfn|Harvey|2011|p=158}} The historic, never-before-seen views of the far side of the Moon caused excitement and interest when they were published around the world, and a tentative ''Atlas of the Far Side of the Moon'' was created from the pictures.

These views showed mountainous terrain, very different from the near side, and only two dark, low-lying regions, which were named [[Mare Moscoviense]] (Sea of Moscow) and [[Mare Desiderii]] (Sea of Desire). Mare Desiderii was later found to be composed of a smaller mare, [[Mare Ingenii]] (Sea of Cleverness), and several other dark craters.  The reason for this difference between the two sides of the Moon is still not fully understood, but it seems that most of the dark lavas that flowed out to produce the [[lunar maria|maria]] formed under the Earth-facing half.<ref name="ianridpath1">{{cite web|url=http://www.ianridpath.com/moon/moon1.htm |title=Exploring the Moon – The first robot explorers |publisher=Ianridpath.com |access-date=2013-11-06}}</ref>