... trace their heritage to the interstellar medium from which the protosolar nebula eventually emerged. The most recent cometary space mission, Rosetta , carried instruments designed to characterize, in unprecedented detail, the organic species in comet 67P/Churyumov–Gerasimenko (67P). Rosetta...

...Scott A. Sandford; Scott Messenger; Michael DiSanti; Lindsay Keller; Kathrin Altwegg Abstract Comets are thought to have accreted in the cold, outer portions of the protosolar nebula when our Solar System was forming, and they clearly contain a higher proportion of volatiles than materials formed...

... Rosetta mission to comet 67P/Churyumov–Gerasimenko ( Meech 2017 ). Molecular species that sublimate directly from a comet's nucleus are called “parent molecules” and their photo-dissociation products are called “daughter species”. Most of the species observed at optical wavelengths do not represent...

... density. Matter must have assembled with low relative speed to create the contact-binary and onion-shell morphology of comet 67P/Churyumov–Gerasimenko, observed in close proximity by the Rosetta mission (see Grady et al. 2018 this issue). Once they had formed, some comets were scattered during close...

.... Prior to the investigation of comet 67P/Churyumov–Gerasimenko by the European Space Agency's Rosetta mission (Grady et al. 2018 this issue), there had been close encounters with six other comets ( Fig. 1 ). Rosetta included both a rendezvous spacecraft for extended measurements near the comet...

... orders of magnitude (see Fig. 2 ). In the latest giant step, the Rosetta spacecraft orbited, and deposited a probe on comet 67P/Churyumov–Gerasimenko, as described by Grady et al. (2018 this issue). In many ways, we live at the perfect time to be “cometologists”. However, the mission that most...

...F igure 5 An agglomerate dust particle from comet 67P/Churyumov–Gerasimenko, as collected by COSIMA (cometary secondary ion mass analyzer). The image was obtained using grazing illumination from the right. The length of the shadows indicates that the altitude above the substrate reaches about...

... imagination in a way little else can. Who could not be enthralled by the evocatively named Stardust mission returning a few thousand grains of dust from comet Wild 2 to Earth? We collectively shared the despair when communication was lost from Rosetta 's Philae lander on comet 67P/Churyumov–Gerasimenko...

... and asteroids . Nature 342 : 255 - 257 Altwegg K 31 coauthors ( 2016 ) Prebiotic chemicals—amino acid and phosphorus—in the coma of comet 67P/Churyumov-Gerasimenko . Science Advances 2 : E1600285 , doi: 10.1126/sciadv.1600285 Bada JL ( 2013 ) New insights into prebiotic...

... and Grady 2018 this issue). Micrometeorites likely derive from comets and asteroids (see Elements 2016, v12, n3). Space missions to comets and asteroids. Recent missions (such as the European Space Agency's Rosetta mission to Comet 67P/Churyumov–Gerasimenko, the Japan Aerospace Exploration Agency's...

... of chondritic-porous IDPs are consistent with the very low strength of cometary meteors. Indeed, chondritic-porous IDPs are remarkably similar in appearance to particle aggregates from the comet 67P/Churyumov–Gerasimenko, which was recently analyzed by the COSIMA instrument on the Rosetta spacecraft...

...Figure 8 Examples of extraterrestrial case hardening. ( A ) Image of the surface of comet 67P/Churyumov–Gerasimenko (view is ~900 m across). While dust appears to generate smooth surfaces, unknown agents have created induration features, as evidenced by eroded edges of the crust (arrowed). Image...