Editing Rosetta (spacecraft) (section)

=== Preliminary results ===
{{main|67P/Churyumov–Gerasimenko}}
The mission has yielded a significant science return, collecting a wealth of data from the nucleus and its environment at various levels of cometary activity.<ref>{{cite conference |url=http://meetingorganizer.copernicus.org/EGU2016/EGU2016-17068.pdf |title=Rosetta Mission Status: Toward the End of Comet Phase Operations |conference=EGU General Assembly 2016. 17–22 April 2016. Vienna Austria. |first=Patrick |last=Martin |date=April 2016 |bibcode=2016EGUGA..1817068M |id=EGU2016-17068}}</ref> The VIRTIS [[spectrometer]] on board the ''Rosetta'' spacecraft has provided evidence of nonvolatile organic macromolecular compounds everywhere on the surface of comet 67P with little to no water ice visible.<ref name="Capaccioni2015">{{cite journal |title=The organic-rich surface of comet 67P/Churyumov-Gerasimenko as seen by VIRTIS/Rosetta |journal=[[Science (journal)|Science]] |first1=F. |last1=Capaccioni |first2=A. |last2=Coradini |first3=G. |last3=Filacchione |first4=S. |last4=Erard |first5=G. |last5=Arnold |first6=P. |last6=Drossart |first7=M. C. |last7=de Sanctis |first8=D. |last8=Bockelée-Morvan |first9=M. T. |last9=Capria |first10=F. |last10=Tosi |first11=C. |last11=Leyrat |first12=B. |last12=Schmitt |first13=E. |last13=Quirico |first14=P. |last14=Cerroni |first15=V. |last15=Mennella |first16=A. |last16=Raponi |first17=M. |last17=Ciarniello |first18=T. |last18=McCord |first19=L. |last19=Moroz |first20=E. |last20=Ammannito |display-authors=5 |volume=347 |issue=6220 |pages=aaa0628 |date=23 January 2015 |doi=10.1126/science.aaa0628 |bibcode=2015Sci...347a0628C |pmid=25613895 |s2cid=206632659 |doi-access=free }}</ref> Preliminary analyses strongly suggest the carbon is present as [[Aromatic hydrocarbon|polyaromatic]] organic solids mixed with [[sulfide]]s and iron-nickel alloys.<ref name="Quirico2015">{{cite conference |url=http://www.hou.usra.edu/meetings/lpsc2015/pdf/2092.pdf |title=Composition of Comet 67P/Churymov-Gerasimenko Refractory Crust as Inferred from VIRTIS-M/Rosetta Spectro-Imager |conference=46th Lunar and Planetary Science Conference. 16–20 March 2015. The Woodlands, Texas. |first1=E. |last1=Quirico |first2=L. V. |last2=Moroz |first3=P. |last3=Beck |first4=B. |last4=Schmitt |first5=G. |last5=Arnold |first6=L. |last6=Bona |first7=G. |last7=Filacchione |first8=F. |last8=Capaccioni |first9=C. |last9=Leyrat |first10=D. |last10=Bockelée-Morvan |first11=S. |last11=Erard |first12=F. |last12=Tosi |first13=M. |last13=Ciarniello |first14=A. |last14=Raponi |first15=M. T. |last15=Capria |first16=M. C. |last16=de Sanctis |first17=G. |last17=Piccioni |first18=A. |last18=Barucci |first19=P. |last19=Drossart |first20=K. |last20=Marcus |display-authors=5 |date=March 2015 |id=LPI Contribution No. 1832, p. 2092 |bibcode=2015LPI....46.2092Q}}</ref><ref name="quirco-2016">{{cite journal |title=Refractory and semi-volatile organics at the surface of comet 67P/Churyumov-Gerasimenko: Insights from the VIRTIS/Rosetta imaging spectrometer |journal=Icarus |last1=Quirico |first1=E. |last2=Moroz |first2=L. V. |last3=Schmitt |first3=B. |last4=Arnold |first4=G. |last5=Faure |first5=M. |display-authors=etal |volume=272 |pages=32–47 |date=July 2016 |doi=10.1016/j.icarus.2016.02.028 |bibcode=2016Icar..272...32Q |url=https://elib.dlr.de/124877/1/rousseau_submicron_icarus_preprint_2018.pdf}}</ref>

Solid organic compounds were also found in the dust particles emitted by the comet; the carbon in this organic material is bound in "very large macromolecular compounds", analogous to those found in [[carbonaceous chondrite]] meteorites.<ref name="Fray 2016">{{cite journal |title=High-molecular-weight organic matter in the particles of comet 67P/Churyumov–Gerasimenko |journal=Nature |last1=Fray |first1=Nicolas |last2=Bardyn |first2=Anaïs |last3=Cottin |first3=Hervé |display-authors=etal |volume=538 |issue=7623 |pages=72–74 |date=6 October 2016 |doi=10.1038/nature19320 |pmid=27602514 |bibcode=2016Natur.538...72F|s2cid=205250295 }}</ref> However, no hydrated minerals were detected, suggesting no link with carbonaceous chondrites.<ref name="quirco-2016" />

In turn, the ''Philae'' lander's COSAC instrument detected organic molecules in the comet's atmosphere as it descended to its surface.<ref name="bbcnews20141118">{{cite news |url=https://www.bbc.com/news/science-environment-30097648 |title=Comet landing: Organic molecules detected by Philae |work=BBC News |first=Paul |last=Rincon |date=18 November 2014 |access-date=6 April 2015}}</ref><ref name="guardian20141119">{{cite news |url=https://www.theguardian.com/science/2014/nov/18/philae-lander-comet-surface-detects-organic-molecules |title=Rosetta mission lander detects organic molecules on surface of comet |work=The Guardian |first=Richard |last=Grey |date=19 November 2014 |access-date=6 April 2015}}</ref> Measurements by the COSAC and Ptolemy instruments on the ''Philae''{{'s}} lander revealed sixteen [[organic compound]]s, four of which were seen for the first time on a comet, including [[acetamide]], [[acetone]], [[methyl isocyanate]] and [[propionaldehyde]].<ref name="wapo20150730">{{cite news |url=https://www.usnews.com/news/world/articles/2015/07/30/philae-probe-finds-evidence-that-comets-can-be-cosmic-labs |title=Philae probe gets a 'sniff' of acetone, indicating comets can concoct complex compounds |work=[[U.S. News & World Report]] |agency=Associated Press |first=Frank |last=Jordans |date=30 July 2015 |access-date=5 October 2016}}</ref><ref name="esa20150730">{{cite web |url=http://www.esa.int/Our_Activities/Space_Science/Rosetta/Science_on_the_surface_of_a_comet |title=Science on the Surface of a Comet |publisher=European Space Agency |date=30 July 2015 |access-date=30 July 2015}}</ref><ref name="SCI-20150731">{{cite journal |last1=Bibring |first1=J.-P. |last2=Taylor |first2=M.G.G.T. |last3=Alexander |first3=C. |last4=Auster |first4=U. |last5=Biele |first5=J. |last6=Finzi |first6=A. Ercoli |last7=Goesmann |first7=F. |last8=Klingehoefer |first8=G. |last9=Kofman |first9=W. |last10=Mottola |first10=S. |last11=Seidenstiker |first11=K.J. |last12=Spohn |first12=T. |last13=Wright |first13=I. |title=Philae's First Days on the Comet – Introduction to Special Issue |date=31 July 2015 |journal=[[Science (journal)|Science]] |volume=349 |issue=6247 |page=493 |doi=10.1126/science.aac5116 |bibcode=2015Sci...349..493B |pmid=26228139 |s2cid=206639354 |url=http://elib.dlr.de/97953/1/Science-2015-Bibring-493.pdf|doi-access=free }}</ref> The only amino acid detected thus far on the comet is [[glycine]], along with the precursor molecules [[methylamine]] and [[ethylamine]].<ref name="Altwegg 2016">{{cite journal |title=Prebiotic chemicals—amino acid and phosphorus—in the coma of comet 67P/Churyumov–Gerasimenko |journal=Science Advances |last1=Altwegg |first1=Kathrin|author1-link=Kathrin Altwegg |display-authors=etal |volume=2 |issue=5 |pages=e1600285 |date=27 May 2016 |doi=10.1126/sciadv.1600285 |pmid=27386550 |pmc=4928965 |bibcode=2016SciA....2E0285A}}</ref>

One of the most outstanding discoveries of the mission was the detection of large amounts of free molecular [[oxygen]] ({{chem2|O2}}) gas surrounding the comet.<ref name="Bieler 2015">{{cite journal |title=Abundant molecular oxygen in the coma of comet 67P/Churyumov–Gerasimenko |journal=Nature |date=29 October 2015 |last=Bieler |first=A. |display-authors=etal |volume=526 |issue=7575 |pages=678–681 |doi=10.1038/nature15707 |pmid=26511578 |bibcode=2015Natur.526..678B |s2cid=205246191 |url=https://hal.archives-ouvertes.fr/hal-01346075/file/O2_letter_v4.pdf}}</ref><ref name="Howel 2015">{{cite news |last=Howell |first=Elizabeth |url=http://www.space.com/30961-modern-mystery-ancient-comet-spewing-oxygen.html?adbid=10153138402681466&adbpl=fb&adbpr=17610706465 |title=Modern Mystery: Ancient Comet Is Spewing Oxygen |work=Space.com |date=28 October 2015 |access-date=6 November 2015}}</ref> A local abundance of [[oxygen]] was reported to be in range from 1% to 10% relative to H<sub>2</sub>O.<ref name="Bieler 2015" />