scholarly journals The Rosetta mission orbiter science overview: the comet phase

2017 ◽  
Vol 375 (2097) ◽  
pp. 20160262 ◽  
Author(s):  
M. G. G. T. Taylor ◽  
N. Altobelli ◽  
B. J. Buratti ◽  
M. Choukroun
Keyword(s):  
Remote Sensing ◽  
Solar System ◽  
Cometary Nucleus ◽  
Rosetta Mission ◽  
Interstellar Material ◽  
The Relationship ◽  
Mission Operations ◽  
Comet 67P ◽  
Cometary Activity

The international Rosetta mission was launched in 2004 and consists of the orbiter spacecraft Rosetta and the lander Philae. The aim of the mission is to map the comet 67P/Churyumov–Gerasimenko by remote sensing, and to examine its environment in situ and its evolution in the inner Solar System. Rosetta was the first spacecraft to rendezvous with and orbit a comet, accompanying it as it passes through the inner Solar System, and to deploy a lander, Philae, and perform in situ science on the comet's surface. The primary goals of the mission were to: characterize the comet's nucleus; examine the chemical, mineralogical and isotopic composition of volatiles and refractories; examine the physical properties and interrelation of volatiles and refractories in a cometary nucleus; study the development of cometary activity and the processes in the surface layer of the nucleus and in the coma; detail the origin of comets, the relationship between cometary and interstellar material and the implications for the origin of the Solar System; and characterize asteroids 2867 Steins and 21 Lutetia. This paper presents a summary of mission operations and science, focusing on the Rosetta orbiter component of the mission during its comet phase, from early 2014 up to September 2016. This article is part of the themed issue ‘Cometary science after Rosetta’.

scholarly journals The Rosetta Mission to Primitive Bodies of the Solar System

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.

scholarly journals Elemental and molecular abundances in comet 67P/Churyumov-Gerasimenko

2019 ◽  
Vol 489 (1) ◽  
pp. 594-607 ◽  
Author(s):  
Martin Rubin ◽  
Kathrin Altwegg ◽  
Hans Balsiger ◽  
Jean-Jacques Berthelier ◽  
Michael R Combi ◽  
...  
Keyword(s):  
Solar System ◽  
Early Period ◽  
Major Elements ◽  
Rosetta Mission ◽  
Solar System Objects ◽  
Dust Composition ◽  
Solar Abundances ◽  
Molecular Abundances ◽  
Comet 67P

ABSTRACT Comets are considered to be some of the most pristine and unprocessed Solar system objects accessible to in situ exploration. Investigating their molecular and elemental composition takes us on a journey back to the early period of our Solar system and possibly even further. In this work, we deduce the bulk abundances of the major volatile species in comet 67P/Churyumov-Gerasimenko, the target of the European Space Agency’s (ESA) Rosetta mission. The basis are measurements obtained with the ROSINA instrument suite on board the Rosetta orbiter during a suitable period of high outgassing near perihelion. The results are combined with both gas and dust composition measurements published in the literature. This provides an integrated inventory of the major elements present in the nucleus of 67P/Churyumov-Gerasimenko. Similar to comet 1P/Halley, which was visited by ESA’s Giotto spacecraft in 1986, comet 67P/Churyumov-Gerasimenko also shows near-solar abundances of oxygen and carbon, whereas hydrogen and nitrogen are depleted compared to solar. Still, the degree of devolatilization is lower than that of inner Solar system objects, including meteorites and the Earth. This supports the idea that comets are amongst the most pristine objects in our Solar system.

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

2019 ◽  
Vol 489 (4) ◽  
pp. 4734-4740 ◽  
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.

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

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.

scholarly journals Estimating the Height and Basal Area at Individual Tree and Plot Levels in Canadian Subarctic Lichen Woodlands Using Stereo WorldView-3 Images

2019 ◽  
Vol 11 (3) ◽  
pp. 248 ◽  
Author(s):  
Benoît St-Onge ◽  
Simon Grandin
Keyword(s):  
Remote Sensing ◽  
Basal Area ◽  
Ground Cover ◽  
Structural Data ◽  
Tree Level ◽  
Individual Tree ◽  
Visual Contrast ◽  
The Relationship ◽  
Height Data

Lichen woodlands (LW) are sparse forests that cover extensive areas in remote subarctic regions where warming due to climate change is fastest. They are difficult to study in situ or with airborne remote sensing due to their remoteness. We have tested a method for measuring individual tree heights and predicting basal area at tree and plot levels using WorldView-3 stereo images. Manual stereo measurements of tree heights were performed on short trees (2–12 m) of a LW region of Canada with a residual standard error of ≈0.9 m compared to accurate field or UAV height data. The number of detected trees significantly underestimated field counts, especially in peatlands in which the visual contrast between trees and ground cover was low. The heights measured from the WorldView-3 images were used to predict the basal area at individual tree level and summed up at plot level. In the best conditions (high contrast between trees and ground cover), the relationship to field basal area had a R2 of 0.79. Accurate estimates of above ground biomass should therefore also be possible. This method could be used to calibrate an extensive remote sensing approach without in-situ measurements, e.g., by linking precise structural data to ICESAT-2 footprints.

scholarly journals Cometary Chemistry and the Origin of Icy Solar System Bodies: The View After Rosetta

2019 ◽  
Vol 57 (1) ◽  
pp. 113-155 ◽  
Author(s):  
Kathrin Altwegg ◽  
Hans Balsiger ◽  
Stephen A. Fuselier
Keyword(s):  
Solar System ◽  
Protoplanetary Disk ◽  
Isotopic Ratios ◽  
Parent Species ◽  
Rosetta Mission ◽  
Solar System Bodies ◽  
Diverse Origin ◽  
Life On Earth ◽  
Collapsing Cloud

In situ research of cometary chemistry began when measurements from the Giotto mission at Comet 1P/Halley revealed the presence of complex organics in the coma. New telescopes and space missions have provided detailed remote and in situ measurements of the composition of cometary volatiles. Recently, the Rosetta mission to Comet 67P/Churyumov–Gerasimenko (67P) more than doubled the number of parent species and the number of isotopic ratios known for comets. Forty of the 71 parent species have also been detected in pre- and protostellar clouds. Most isotopic ratios are nonsolar. This diverse origin is in contrast to that of the Sun, which received its material from the bulk of the collapsing cloud. The xenon isotopic ratios measured in 67P can explain the long-standing question about the origin of terrestrial atmospheric xenon. These findings strengthen the notion that comets are indeed an important link between the ISM and today's solar system including life on Earth. ▪ Nonsolar isotopic ratios for species such as Xe, N, S, and Si point to a nonhomogenized protoplanetary disk from which comets received their material. ▪ The similarity of the organic inventories of comets and presolar and protostellar material makes it plausible that this material was accreted almost unaltered by comets from the presolar stage. ▪ Large variations in the deuterium-to-hydrogen ratio in water for comets indicate a large range in the protoplanetary disk from which comets formed. ▪ The amount of organics delivered by comets to Earth may be highly significant.

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

2019 ◽  
Vol 630 ◽  
pp. A29 ◽  
Author(s):  
Isaac R. H. G. Schroeder I ◽  
Kathrin Altwegg ◽  
Hans Balsiger ◽  
Jean-Jacques Berthelier ◽  
Johan De Keyser ◽  
...  
Keyword(s):  
Solar System ◽  
Mass Spectrometer ◽  
European Space Agency ◽  
Space Agency ◽  
Close Proximity ◽  
Terrestrial Water ◽  
Double Focusing ◽  
Comet 67P ◽  
Almost Continuous

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.

Atmospheric Entry Probes for in situ Exploration of the Ice Giant Planets

2021 ◽  
Author(s):  
David H. Atkinson ◽  
Olivier J. Mousis ◽  
Mark Hofstadter ◽  
Sushil K. Atreya
Keyword(s):  
Remote Sensing ◽  
Solar System ◽  
Noble Gas ◽  
Thermal Structure ◽  
Giant Planets ◽  
Atmospheric Entry ◽  
Cloud Properties ◽  
Entry Probe ◽  
Galileo Probe

&lt;p&gt;Understanding the formation and evolution of the solar system and the formation of the giant planets is constrained by inherent limitations in the capabilities of remote sensing. In situ exploration of planetary atmospheres provides key measurements not possible from remote observations, remarkably demonstrated at Jupiter by the Galileo probe, where key measurements included the determination of noble gas abundances and the precise measurement of the Jupiter helium mixing ratio. In this paper, we describe the primary scientific goals to be addressed by future in situ exploration of the ice giants Uranus and Neptune, placing in situ explorations of the gas giants, including the Galileo probe and a future Saturn probe, into a broader solar system context. An ice giant atmospheric entry probe reaching 10 bars would provide insight into both the formation history of the solar system and the giant planets, and the structure and composition of, and physical processes at play within ice giant atmospheres. An entry probe as an element of a future ice giant flagship mission would descend under parachute to measure the abundances and isotopic ratios of the noble gases, D/H in H&lt;sub&gt;2&lt;/sub&gt; and &lt;sup&gt;13&lt;/sup&gt;C/&lt;sup&gt;12&lt;/sup&gt;C, and the thermal structure and dynamics from the upper atmosphere down to the deepest region from which the probe is able to return data, perhaps 10-20 bars or more. Probe data would be returned to Earth using a Carrier Relay Spacecraft as a relay station. The relay spacecraft, particularly if it is an orbiter with a suite of remote sensing instruments, can significantly enhance the science return from the probe; remote sensing provides the global context from which to understand the probe's local measurements of weather and cloud properties. One or more small atmospheric probes could represent a significant ESA contribution to a future NASA New Frontiers or Flagship Ice Giant mission.&lt;/p&gt; &lt;p&gt;&amp;#160;&lt;/p&gt;

scholarly journals The 67P/Churyumov–Gerasimenko observation campaign in support of the Rosetta mission

2017 ◽  
Vol 375 (2097) ◽  
pp. 20160249 ◽  
Author(s):  
C. Snodgrass ◽  
M. F. A'Hearn ◽  
F. Aceituno ◽  
V. Afanasiev ◽  
S. Bagnulo ◽  
...  
Keyword(s):  
Large Scale ◽  
Activity Patterns ◽  
Mission Planning ◽  
Context Information ◽  
Large Collection ◽  
Future Studies ◽  
Early Results ◽  
Rosetta Mission ◽  
Comet 67P

We present a summary of the campaign of remote observations that supported the European Space Agency's Rosetta mission. Telescopes across the globe (and in space) followed comet 67P/Churyumov–Gerasimenko from before Rosetta's arrival until nearly the end of the mission in September 2016. These provided essential data for mission planning, large-scale context information for the coma and tails beyond the spacecraft and a way to directly compare 67P with other comets. The observations revealed 67P to be a relatively ‘well-behaved’ comet, typical of Jupiter family comets and with activity patterns that repeat from orbit to orbit. Comparison between this large collection of telescopic observations and the in situ results from Rosetta will allow us to better understand comet coma chemistry and structure. This work is just beginning as the mission ends—in this paper, we present a summary of the ground-based observations and early results, and point to many questions that will be addressed in future studies. This article is part of the themed issue ‘Cometary science after Rosetta’.

scholarly journals Outgassing-induced acceleration of comet 67P/Churyumov-Gerasimenko

2019 ◽  
Vol 630 ◽  
pp. A4 ◽  
Author(s):  
T. Kramer ◽  
M. Läuter
Keyword(s):  
Rotation Axis ◽  
Gravitational Acceleration ◽  
Axis Orientation ◽  
Fourier Decomposition ◽  
Sublimation Process ◽  
Rosetta Mission ◽  
Position Data ◽  
Comet 67P ◽  
Local Noon

Context. Cometary activity affects the orbital motion and rotation state through sublimation-induced forces. The availability of precise rotation-axis orientation and position data from the Rosetta mission allows us to accurately determine the outgassing of comet Churyumov-Gerasimenko/67P (67P). Aims. We derived the observed non-gravitational acceleration of 67P directly from the trajectory of the Rosetta spacecraft. From the non-gravitational acceleration, we recovered the diurnal outgassing variations and study a possible delay of the sublimation response with respect to the peak of the solar illumination. This allowed us to compare the non-gravitational acceleration of 67P with expectations based on empirical models and common assumptions about the sublimation process. Methods. We used an iterative orbit refinement and Fourier decomposition of the diurnal activity to derive the outgassing-induced non-gravitational acceleration. The uncertainties of the data reduction were established by a sensitivity analysis of an ensemble of best-fit orbits for comet 67P. Results. We find that the Marsden non-gravitational acceleration parameters reproduce part of the non-gravitational acceleration, but need to be augmented by an analysis of the nucleus geometry and surface illumination to draw conclusions about the sublimation process on the surface. The non-gravitational acceleration closely follows the subsolar latitude (seasonal illumination), with a small lag angle with respect to local noon around perihelion. The observed minor changes of the rotation axis do not favor forced precession models for the non-gravitational acceleration. Conclusions. In contrast to the sublimation-induced torques, the non-gravitational acceleration does not place strong constraints on localized active areas on the nucleus. We find a close agreement of the orbit-deduced non-gravitational acceleration and the water production that is independently derived from Rosetta in situ measurements.

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