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Detection of argon in the coma of comet 67P/Churyumov-Gerasimenko.

Balsiger H, Altwegg K, Bar-Nun A, Berthelier JJ, Bieler A, Bochsler P, Briois C, Calmonte U, Combi M, De Keyser J, Eberhardt P, Fiethe B, Fuselier SA, Gasc S, Gombosi TI, Hansen KC, Hässig M, Jäckel A, Kopp E, Korth A, Le Roy L, Mall U, Marty B, Mousis O, Owen T, Rème H, Rubin M, Sémon T, Tzou CY, Waite JH, Wurz P - Sci Adv (2015)

Bottom Line: We report the detection of argon and its relation to the water abundance in the Jupiter family comet 67P/Churyumov-Gerasimenko by in situ measurement of the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) mass spectrometer aboard the Rosetta spacecraft.Despite the very low intensity of the signal, argon is clearly identified by the exact determination of the mass of the isotope (36)Ar and by the (36)Ar/(38)Ar ratio.Because of time variability and spatial heterogeneity of the coma, only a range of the relative abundance of argon to water can be given.

View Article: PubMed Central - PubMed

Affiliation: Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland.

ABSTRACT
Comets have been considered to be representative of icy planetesimals that may have contributed a significant fraction of the volatile inventory of the terrestrial planets. For example, comets must have brought some water to Earth. However, the magnitude of their contribution is still debated. We report the detection of argon and its relation to the water abundance in the Jupiter family comet 67P/Churyumov-Gerasimenko by in situ measurement of the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) mass spectrometer aboard the Rosetta spacecraft. Despite the very low intensity of the signal, argon is clearly identified by the exact determination of the mass of the isotope (36)Ar and by the (36)Ar/(38)Ar ratio. Because of time variability and spatial heterogeneity of the coma, only a range of the relative abundance of argon to water can be given. Nevertheless, this range confirms that comets of the type 67P/Churyumov-Gerasimenko cannot be the major source of Earth's major volatiles.

No MeSH data available.


Related in: MedlinePlus

D/H versus 36Ar/H2O mixing of 67P/CG-like and asteroidal materials.The asteroidal composition is represented by the Orgueil (CI) and Murchison (CM) carbonaceous chondrites. CI/CM chondrites are considered as the best representatives of volatile-rich primitive meteorites (19). Cometary data: this work, Altwegg et al. (10). Meteorite data: Mazor et al., Bogard et al., and Kerridge (20–22). Earth data, surface inventory: Lécuyer et al. and Ozima et al. (12, 13). Range of estimates for bulk Earth: Marty and Halliday (17, 18).
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Figure 3: D/H versus 36Ar/H2O mixing of 67P/CG-like and asteroidal materials.The asteroidal composition is represented by the Orgueil (CI) and Murchison (CM) carbonaceous chondrites. CI/CM chondrites are considered as the best representatives of volatile-rich primitive meteorites (19). Cometary data: this work, Altwegg et al. (10). Meteorite data: Mazor et al., Bogard et al., and Kerridge (20–22). Earth data, surface inventory: Lécuyer et al. and Ozima et al. (12, 13). Range of estimates for bulk Earth: Marty and Halliday (17, 18).

Mentions: Combining the D/H and 36Ar/H2O ratios measured in the coma of 67P/CG provides a means of quantification of a possible cometary contribution to Earth from a body with volatile content, such as 67P/CG (Fig. 3). Earth is represented by the surface inventory (hydrosphere plus atmosphere) and by bulk Earth (surface plus deep Earth) estimates from (17) and (18), respectively. Clearly, an asteroidal component, represented by carbonaceous chondrites CI and CM in Fig. 3, makes a better potential contributor to terrestrial water [and other major volatiles such as C and N (17)] than comets. Mixing curves between the two components allows the definition of potential cometary contributions, assuming no fractionation of the 36Ar/H2O ratio during delivery. Depending on the 36Ar/H2O values adopted for bulk Earth, a contribution of cometary argon to the atmosphere is possible, but a contribution of 67P/CG-like material to terrestrial water is negligible in all cases. If one considers bulk Earth composition as defined by Marty (17) (lower limit of the 36Ar/H2O in Fig. 3), a bulk terrestrial 36Ar/H2O ratio close to chondritic leaves no room for significant contribution of 67P/CG-like material to the major volatiles on Earth.


Detection of argon in the coma of comet 67P/Churyumov-Gerasimenko.

Balsiger H, Altwegg K, Bar-Nun A, Berthelier JJ, Bieler A, Bochsler P, Briois C, Calmonte U, Combi M, De Keyser J, Eberhardt P, Fiethe B, Fuselier SA, Gasc S, Gombosi TI, Hansen KC, Hässig M, Jäckel A, Kopp E, Korth A, Le Roy L, Mall U, Marty B, Mousis O, Owen T, Rème H, Rubin M, Sémon T, Tzou CY, Waite JH, Wurz P - Sci Adv (2015)

D/H versus 36Ar/H2O mixing of 67P/CG-like and asteroidal materials.The asteroidal composition is represented by the Orgueil (CI) and Murchison (CM) carbonaceous chondrites. CI/CM chondrites are considered as the best representatives of volatile-rich primitive meteorites (19). Cometary data: this work, Altwegg et al. (10). Meteorite data: Mazor et al., Bogard et al., and Kerridge (20–22). Earth data, surface inventory: Lécuyer et al. and Ozima et al. (12, 13). Range of estimates for bulk Earth: Marty and Halliday (17, 18).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4643765&req=5

Figure 3: D/H versus 36Ar/H2O mixing of 67P/CG-like and asteroidal materials.The asteroidal composition is represented by the Orgueil (CI) and Murchison (CM) carbonaceous chondrites. CI/CM chondrites are considered as the best representatives of volatile-rich primitive meteorites (19). Cometary data: this work, Altwegg et al. (10). Meteorite data: Mazor et al., Bogard et al., and Kerridge (20–22). Earth data, surface inventory: Lécuyer et al. and Ozima et al. (12, 13). Range of estimates for bulk Earth: Marty and Halliday (17, 18).
Mentions: Combining the D/H and 36Ar/H2O ratios measured in the coma of 67P/CG provides a means of quantification of a possible cometary contribution to Earth from a body with volatile content, such as 67P/CG (Fig. 3). Earth is represented by the surface inventory (hydrosphere plus atmosphere) and by bulk Earth (surface plus deep Earth) estimates from (17) and (18), respectively. Clearly, an asteroidal component, represented by carbonaceous chondrites CI and CM in Fig. 3, makes a better potential contributor to terrestrial water [and other major volatiles such as C and N (17)] than comets. Mixing curves between the two components allows the definition of potential cometary contributions, assuming no fractionation of the 36Ar/H2O ratio during delivery. Depending on the 36Ar/H2O values adopted for bulk Earth, a contribution of cometary argon to the atmosphere is possible, but a contribution of 67P/CG-like material to terrestrial water is negligible in all cases. If one considers bulk Earth composition as defined by Marty (17) (lower limit of the 36Ar/H2O in Fig. 3), a bulk terrestrial 36Ar/H2O ratio close to chondritic leaves no room for significant contribution of 67P/CG-like material to the major volatiles on Earth.

Bottom Line: We report the detection of argon and its relation to the water abundance in the Jupiter family comet 67P/Churyumov-Gerasimenko by in situ measurement of the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) mass spectrometer aboard the Rosetta spacecraft.Despite the very low intensity of the signal, argon is clearly identified by the exact determination of the mass of the isotope (36)Ar and by the (36)Ar/(38)Ar ratio.Because of time variability and spatial heterogeneity of the coma, only a range of the relative abundance of argon to water can be given.

View Article: PubMed Central - PubMed

Affiliation: Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland.

ABSTRACT
Comets have been considered to be representative of icy planetesimals that may have contributed a significant fraction of the volatile inventory of the terrestrial planets. For example, comets must have brought some water to Earth. However, the magnitude of their contribution is still debated. We report the detection of argon and its relation to the water abundance in the Jupiter family comet 67P/Churyumov-Gerasimenko by in situ measurement of the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) mass spectrometer aboard the Rosetta spacecraft. Despite the very low intensity of the signal, argon is clearly identified by the exact determination of the mass of the isotope (36)Ar and by the (36)Ar/(38)Ar ratio. Because of time variability and spatial heterogeneity of the coma, only a range of the relative abundance of argon to water can be given. Nevertheless, this range confirms that comets of the type 67P/Churyumov-Gerasimenko cannot be the major source of Earth's major volatiles.

No MeSH data available.


Related in: MedlinePlus