16O/18O ratio in water in the coma of comet 67P/Churyumov-Gerasimenko measured with the Rosetta/ROSINA double-focusing mass spectrometer

The European Space Agency spacecraft Rosetta accompanied the Jupiter-family comet 67P/Churyumov-Gerasimenko for over 2 yr along its trajectory through the inner solar system. Between 2014 and 2016, it performed almost continuous in situ measurements of the comet’s gaseous atmosphere in close proximity to its nucleus. In this study, the 16O/18O ratio of H2O in the coma of 67P/Churyumov-Gerasimenko, as measured by the ROSINA DFMS mass spectrometer onboard Rosetta, was determined from the ratio of H216O/H218O and 16OH/18OH. The value of 445 ± 35 represents an ~11% enrichment of 18O compared with the terrestrial ratio of 498.7 ± 0.1. This cometary value is consistent with the comet containing primordial water, in accordance with leading self-shielding models. These models predict primordial water to be between 5 and 20% enriched in heavier oxygen isotopes compared to terrestrial water.

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A comparison between the two lobes of comet 67P/Churyumov–Gerasimenko based on D/H ratios in H2O measured with the Rosetta/ROSINA DFMS

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz2482 ◽

2019 ◽

Vol 489 (4) ◽

pp. 4734-4740 ◽

Cited By ~ 4

Author(s):

Isaac R H G Schroeder ◽

Kathrin Altwegg ◽

Hans Balsiger ◽

Jean-Jacques Berthelier ◽

Michael R Combi ◽

...

Keyword(s):

Mass Spectrometer ◽

European Space Agency ◽

Cometary Nucleus ◽

The Other ◽

Appreciable Difference ◽

Space Agency ◽

Close Proximity ◽

Double Focusing ◽

Comet 67P

ABSTRACT The nucleus of the Jupiter-family comet 67P/Churyumov–Gerasimenko was discovered to be bi-lobate in shape when the European Space Agency spacecraft Rosetta first approached it in 2014 July. The bi-lobate structure of the cometary nucleus has led to much discussion regarding the possible manner of its formation and on how the composition of each lobe might compare with that of the other. During its two-year-long mission from 2014 to 2016, Rosetta remained in close proximity to 67P/Churyumov–Gerasimenko, studying its coma and nucleus in situ. Based on lobe-specific measurements of HDO and H2O performed with the ROSINA Double Focusing Mass Spectrometer (DFMS) on board Rosetta, the deuterium-to-hydrogen (D/H) ratios in water from the two lobes can be compared. No appreciable difference was observed, suggesting that both lobes formed in the same region and are homogeneous in their D/H ratios.

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The Rosetta Mission to Primitive Bodies of the Solar System

Symposium - International Astronomical Union ◽

10.1017/s0074180900046660 ◽

1994 ◽

Vol 160 ◽

pp. 381-394

Author(s):

Yves Langevin

Keyword(s):

Remote Sensing ◽

Solar System ◽

European Space Agency ◽

Time Span ◽

Main Belt ◽

Space Agency ◽

Rosetta Mission ◽

One Year ◽

Definition Of

The European Space Agency (ESA) has selected Rosetta as the next cornerstone mission, to be launched in 2003. The goal is to perfom one or more fly-bys to main belt asteroids, followed by a rendez-vous with an active comet. Advanced in situ analysis, both in the coma and on the surfaces of the nucleus, will be possible, as well as monitoring by remote sensing instruments of the nucleus and of the inner coma for a time span of more than one year, until perihelion. This paper outlines the scientific and technological choices done in the definition of the mission.

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ROSINA ion zoo at Comet 67P

Astronomy and Astrophysics ◽

10.1051/0004-6361/201936775 ◽

2020 ◽

Vol 642 ◽

pp. A27

Author(s):

A. Beth ◽

K. Altwegg ◽

H. Balsiger ◽

J.-J. Berthelier ◽

M. R. Combi ◽

...

Keyword(s):

Solar System ◽

Mass Spectrometer ◽

Mass Resolution ◽

High Mass ◽

Exact Nature ◽

High Mass Resolution ◽

System Body ◽

First Time ◽

Comet 67P

Context. The Rosetta spacecraft escorted Comet 67P/Churyumov-Gerasimenko for 2 yr along its journey through the Solar System between 3.8 and 1.24 au. Thanks to the high resolution mass spectrometer on board Rosetta, the detailed ion composition within a coma has been accurately assessed in situ for the very first time. Aims. Previous cometary missions, such as Giotto, did not have the instrumental capabilities to identify the exact nature of the plasma in a coma because the mass resolution of the spectrometers onboard was too low to separate ion species with similar masses. In contrast, the Double Focusing Mass Spectrometer (DFMS), part of the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis on board Rosetta (ROSINA), with its high mass resolution mode, outperformed all of them, revealing the diversity of cometary ions. Methods. We calibrated and analysed the set of spectra acquired by DFMS in ion mode from October 2014 to April 2016. In particular, we focused on the range from 13–39 u q−1. The high mass resolution of DFMS allows for accurate identifications of ions with quasi-similar masses, separating 13C+ from CH+, for instance. Results. We confirm the presence in situ of predicted cations at comets, such as CHm+ (m = 1−4), HnO+ (n = 1−3), O+, Na+, and several ionised and protonated molecules. Prior to Rosetta, only a fraction of them had been confirmed from Earth-based observations. In addition, we report for the first time the unambiguous presence of a molecular dication in the gas envelope of a Solar System body, namely CO2++.

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Chemistry of the Solar System Revealed in the Interiors of the Giant Planets

Proceedings of the International Astronomical Union ◽

10.1017/s1743921311025026 ◽

2011 ◽

Vol 7 (S280) ◽

pp. 249-260 ◽

Cited By ~ 1

Author(s):

Jonathan I. Lunine

Keyword(s):

Solar System ◽

Microwave Radiometer ◽

Giant Planets ◽

Isotopic Ratios ◽

Data Sets ◽

Terrestrial Water ◽

Galileo Probe ◽

Probe Mission ◽

Juno Mission

AbstractThe giant planets of our solar system contain a record of elemental and isotopic ratios of keen interest for what they tell us about the origin of the planets and in particular the volatile compositions of the solid phases. In situ measurements of the Jovian atmosphere performed by the Galileo Probe during its descent in 1995 demonstrate the unique value of such a record, but limited currently by the unknown abundance of oxygen in the interior of Jupiter–a gap planned to be filled by the Juno mission set to arrive at Jupiter in July of 2016. Our lack of knowledge of the oxygen abundance allows for a number of models for the Jovian interior with a range of C/O ratios. The implications for the origin of terrestrial water are briefly discussed. The complementary data sets for Saturn may be obtained by a series of very close, nearly polar orbits, at the end of the Cassini-Huygens mission in 2016-2017, and the proposed Saturn Probe. This set can only obtain what we have for Jupiter if the Saturn Probe mission carries a microwave radiometer.

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Prospects for Life on Other Planets

Assembling Life ◽

10.1093/oso/9780190646387.003.0017 ◽

2019 ◽

Author(s):

David W. Deamer

Keyword(s):

Solar System ◽

Origin Of Life ◽

Hydrothermal Vents ◽

European Space Agency ◽

Extraterrestrial Life ◽

Major Question ◽

Space Agency ◽

Planetary Bodies ◽

The Origin Of Life ◽

Alternative Scenarios

This book describes a hypothetical process in which populations of protocells can spontaneously assemble and begin to grow and proliferate by energy- dependent polymerization. This might seem to be just an academic question pursued by a few dozen researchers as a matter of curiosity, but in the past three decades advances in engineering have reached a point where both NASA and the European Space Agency (ESA) routinely send spacecraft to other planetary objects in our solar system. A major question being pursued is whether life has emerged elsewhere than on Earth. The limited funds available to support such missions require decisions to be made about target priorities that are guided by judgment calls. These in turn depend on plausible scenarios related to the origin of life on habitable planetary surfaces. We know that other planetary bodies in our solar system have had or do have conditions that would permit microbial life to exist and perhaps even to begin. By a remarkable coincidence, the two most promising objects for extraterrestrial life happen to represent the two alternative scenarios described in this book: An origin of life in conditions of hydrothermal vents or an origin in hydrothermal fields. This final chapter will explore how these alternative views can guide our judgment about where to send future space missions designed as life-detection missions. Questions to be addressed: What is meant by habitability? Which planetary bodies are plausible sites for the origin of life? How do the hypotheses described in this book relate to those sites? There is healthy public interest in how life begins and whether it exists elsewhere in our solar system or on the myriad exoplanets now known to orbit other stars. This has fueled a series of films, television programs, and science fiction novels. Most of these feature extrapolations to intelligent life but a few, such as The Andromeda Strain, explore what might happen if a pathogenic organism from space began to spread to the human population. There is a serious and sustained scientific effort—SETI, or Search for Extraterrestrial Intelligence—devoted to finding an answer to this question.

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The gas production of 14 species from comet 67P/Churyumov–Gerasimenko based on DFMS/COPS data from 2014 to 2016

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa2643 ◽

2020 ◽

Vol 498 (3) ◽

pp. 3995-4004 ◽

Cited By ~ 2

Author(s):

Matthias Läuter ◽

Tobias Kramer ◽

Martin Rubin ◽

Kathrin Altwegg

Keyword(s):

Error Bounds ◽

Temporal Evolution ◽

Gas Production ◽

Total Production ◽

Time Intervals ◽

Triangular Elements ◽

Double Focusing ◽

Comet 67P ◽

Northern And Southern Hemispheres

ABSTRACT The coma of comet 67P/Churyumov–Gerasimenko has been probed by the Rosetta spacecraft and shows a variety of different molecules. The ROSINA COmet Pressure Sensor and the Double Focusing Mass Spectrometer provide in situ densities for many volatile compounds including the 14 gas species H2O, CO2, CO, H2S, O2, C2H6, CH3OH, H2CO, CH4, NH3, HCN, C2H5OH, OCS, and CS2. We fit the observed densities during the entire comet mission between 2014 August and 2016 September to an inverse coma model. We retrieve surface emissions on a cometary shape with 3996 triangular elements for 50 separated time intervals. For each gas, we derive systematic error bounds and report the temporal evolution of the production, peak production, and the time-integrated total production. We discuss the production for the two lobes of the nucleus and for the Northern and Southern hemispheres. Moreover, we provide a comparison of the gas production with the seasonal illumination.

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Joint Discussion 6: Sun and Heliosphere - Challenges for Solar-Terrestrial Physics, Magneto-and Hydrodynamics

Highlights of Astronomy ◽

10.1017/s1539299600011230 ◽

1995 ◽

Vol 10 ◽

pp. 291-293

Author(s):

Martin C.E. Huber ◽

Arne Pedersen ◽

Claus Fröhlich

Keyword(s):

Spatial Scales ◽

Plasma Heating ◽

European Space Agency ◽

Three Dimensional ◽

Plasma Boundary ◽

Small Scale ◽

Space Agency ◽

Terrestrial Magnetosphere ◽

Surrounding Space

There is one astrophysical system, where the sites of a star’s mass loss can be localised and observed in detail, and where the behaviour of the resulting stellar wind in the star’s environment and around orbiting obstacles can be investigated in situ: it is the Sun, the heliosphere and the surroundings of planets — among the latter most prominently the terrestrial magnetosphere. Indeed, within a year or so a fleet of satellites equipped with sophisticated remote-sensing and in-situ instruments will make this astronomical paradigm, or more precisely, the solar-terrestrial system accessible to intensive, multi-disciplinary study.Four identical CLUSTER spacecraft, orbiting the Earth within the magnetosphere, the surrounding space and the particularly interesting plasma boundary layers will perform a three-dimensional in-situ study of plasma-heating, particle-acceleration and other small-scale plasma processes (Schmidt and Goldstein,1988). A number of other missions — some of them already in orbit, like GEOTAIL and WIND, some to be launched within one or two years, like INTERBALL and POLAR — will provide information about the Earth’s magnetosphere and the solar wind on larger spatial scales. These missions are described in a Brochure issued jointly by the European Space Agency, NASA, the Japanese Institute of Space and Astronomical Science and the Rssian Space Agency, which can be obtained from A. Pedersen at the above address.

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The chemical connection between 67P/C-G and IRAS 16293-2422

Proceedings of the International Astronomical Union ◽

10.1017/s1743921317009917 ◽

2017 ◽

Vol 13 (S332) ◽

pp. 196-201

Author(s):

Maria Nikolayevna Drozdovskaya ◽

Ewine F. van Dishoeck ◽

Martin Rubin ◽

Jes Kristian Jørgensen ◽

Kathrin Altwegg

Keyword(s):

Chemical Composition ◽

Solar System ◽

Chemical Evolution ◽

Protoplanetary Disks ◽

In Situ Measurements ◽

Isotopic Ratios ◽

Data Sets ◽

Low Mass ◽

Comet 67P

AbstractThe chemical evolution of a star- and planet-forming system begins in the prestellar phase and proceeds across the subsequent evolutionary phases. The chemical trail from cores to protoplanetary disks to planetary embryos can be studied by comparing distant young protostars and comets in our Solar System. One particularly chemically rich system that is thought to be analogous to our own is the low-mass IRAS 16293-2422. ALMA-PILS observations have made the study of chemistry on the disk scales (<100 AU) of this system possible. Under the assumption that comets are pristine tracers of the outer parts of the innate protosolar disk, it is possible to compare the composition of our infant Solar System to that of IRAS 16293-2422. The Rosetta mission has yielded a wealth of unique in situ measurements on comet 67P/C-G, making it the best probe to date. Herein, the initial comparisons in terms of the chemical composition and isotopic ratios are summarized. Much work is still to be carried out in the future as the analysis of both of these data sets is still ongoing.

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Evaluation of the Performance of SM2RAIN-Derived Rainfall Products over Brazil

Remote Sensing ◽

10.3390/rs11091113 ◽

2019 ◽

Vol 11 (9) ◽

pp. 1113 ◽

Cited By ~ 9

Author(s):

Franklin Paredes-Trejo ◽

Humberto Barbosa ◽

Carlos A. C. dos Santos

Keyword(s):

Soil Moisture ◽

Pearson Correlation ◽

European Space Agency ◽

Rainfall Events ◽

Error Components ◽

Space Agency ◽

Daily Scale ◽

Bioclimatic Conditions ◽

Heavy Rainfall Events

Microwave-based satellite soil moisture products enable an innovative way of estimating rainfall using soil moisture observations with a bottom-up approach based on the inversion of the soil water balance Equation (SM2RAIN). In this work, the SM2RAIN-CCI (SM2RAIN-ASCAT) rainfall data obtained from the inversion of the microwave-based satellite soil moisture (SM) observations derived from the European Space Agency (ESA) Climate Change Initiative (CCI) (from the Advanced SCATterometer (ASCAT) soil moisture data) were evaluated against in situ rainfall observations under different bioclimatic conditions in Brazil. The research V7 version of the Tropical Rainfall Measurement Mission Multi-satellite Precipitation Analysis (TRMM TMPA) was also used as a state-of-the-art rainfall product with an up-bottom approach. Comparisons were made at daily and 0.25° scales, during the time-span of 2007–2015. The SM2RAIN-CCI, SM2RAIN-ASCAT, and TRMM TMPA products showed relatively good Pearson correlation values (R) with the gauge-based observations, mainly in the Caatinga (CAAT) and Cerrado (CER) biomes (R median > 0.55). SM2RAIN-ASCAT largely underestimated rainfall across the country, particularly over the CAAT and CER biomes (bias median < −16.05%), while SM2RAIN-CCI is characterized by providing rainfall estimates with only a slight bias (bias median: −0.20%), and TRMM TMPA tended to overestimate the amount of rainfall (bias median: 7.82%). All products exhibited the highest values of unbiased root mean square error (ubRMSE) in winter (DJF) when heavy rainfall events tend to occur more frequently, whereas the lowest values are observed in summer (JJA) with light rainfall events. The SM2RAIN-based products showed larger contribution of systematic error components than random error components, while the opposite was observed for TRMM TMPA. In general, both SM2RAIN-based rainfall products can be effectively used for some operational purposes on a daily scale, such as water resources management and agriculture, whether the bias is previously adjusted.

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