Editing MESSENGER (section)

== Mission overview ==
''MESSENGER''{{'}}s formal data collection mission began on April 4, 2011.<ref>{{Cite web|url=https://www.youtube.com/watch?v=xQ-dm2zHljk |archive-url=https://ghostarchive.org/varchive/youtube/20211212/xQ-dm2zHljk| archive-date=2021-12-12 |url-status=live|title=Exploring Mercury by Spacecraft: The MESSENGER Mission|date=May 24, 2011 |via=www.youtube.com}}{{cbignore}}</ref> The primary mission was completed on March 17, 2012, having collected close to 100,000 images.<ref name="jhuap14">{{cite press release|url=http://messenger.jhuapl.edu/news_room/details.php?id=198 |title=MESSENGER Provides New Look at Mercury's Landscape, Metallic Core, and Polar Shadows |date=March 21, 2012 |publisher=Johns Hopkins University |access-date=March 22, 2012 |url-status=dead |archive-url=https://web.archive.org/web/20130513081020/http://messenger.jhuapl.edu/news_room/details.php?id=198 |archive-date=May 13, 2013 }}</ref> ''MESSENGER'' achieved 100% mapping of Mercury on March 6, 2013, and completed its first year-long extended mission on March 17, 2013.<ref name=ExMissionCompleted2013>{{cite web|url=http://messenger.jhuapl.edu/news_room/details.php?id=237 |title=MESSENGER Completes Its First Extended Mission at Mercury |publisher=JHU – APL |date=March 18, 2013 |access-date=July 8, 2013 |url-status=dead |archive-url=https://web.archive.org/web/20130729044412/http://messenger.jhuapl.edu/news_room/details.php?id=237 |archive-date=July 29, 2013 }}</ref> The probe's second extended mission lasted for over two years, but as its low orbit degraded, it required reboosts to avoid impact. It conducted its final reboost burns on October 24, 2014, and January 21, 2015, before crashing into Mercury on April 30, 2015.<ref name=EclipseReboost>{{cite web|url=http://www.planetary.org/blogs/emily-lakdawalla/2014/10100759-from-mercury-orbit-messenger.html |title=From Mercury orbit, MESSENGER watches a lunar eclipse|publisher= Planetary Society|date=October 10, 2014|access-date=January 23, 2015}}</ref><ref name='Bang'>{{cite news|url=https://www.bbc.com/news/science-environment-32542646|title=Messenger's Mercury trip ends with a bang, and silence|work=BBC News|date=April 30, 2015|access-date=May 2, 2015}}</ref><ref name=200,000ImagesSurpassed>{{cite web|url=http://messenger.jhuapl.edu/news_room/details.php?id=251|title=MESSENGER Surpasses 200,000 Orbital Images of Mercury|publisher=JHU – APL|date=February 6, 2014|access-date=April 14, 2014|url-status=dead|archive-url=https://web.archive.org/web/20140415084042/http://messenger.jhuapl.edu/news_room/details.php?id=251|archive-date=April 15, 2014}}</ref>

During its stay in Mercury orbit, the probe's instruments yielded significant data, including a characterization of Mercury's magnetic field<ref name = Nantes5/> and the discovery of water [[ice]] at the planet's north pole,<ref name=IceonMercury/><ref>{{cite news |last=Rincon |first=Paul |url=https://www.bbc.com/news/science-environment-29644406 |title=Mercury's hidden water-ice revealed |work=BBC News |date=October 16, 2014 |access-date=October 17, 2014 }}</ref> which had long been suspected on the basis of Earth-based radar data.<ref name="HarmonSlade1994">{{cite journal|last1=Harmon|first1=J. K.|last2=Slade|first2=M. A.|last3=Vélez|first3=R. A.|last4=Crespo|first4=A.|last5=Dryer|first5=M. J.|last6=Johnson|first6=J. M.|title=Radar mapping of Mercury's polar anomalies|journal=Nature|volume=369|issue=6477|date=1994|pages=213–215|issn=0028-0836|doi=10.1038/369213a0|bibcode = 1994Natur.369..213H |s2cid=4320356}}</ref>