Related papers: Terrestrial deuterium-to-hydrogen ratio in water i…
The D/H ratio of water in protostellar systems is a result of both inheritance from the parent molecular cloud and isotopic exchange in the disc. A possibly widespread feature of disc evolution, ignored in previous studies, is accretion…
The high spectral resolution and sensitivity of Herschel/HIFI allows for the detection of multiple rotational water lines and accurate determinations of water production rates in comets. In this letter we present HIFI observations of the…
We present IRTF/SpeX and NEOWISE observations of the dynamically new comet C/2013 US$_{10}$ (Catalina), hereafter US10, from 5.8 au inbound, to near perihelion at 1.3 au, and back to 5.0 au outbound. We detect water ice in the coma of US10,…
We observed the interstellar comet 2I/Borisov using the Neil Gehrels-Swift Observatory's Ultraviolet/Optical Telescope. We obtained images of the OH gas and dust surrounding the nucleus at six epochs spaced before and after perihelion…
We present 5.5 to 7.6 micron spectra of comets 71P/Clark (2006 May 27.56 UT, r_h = 1.57 AU pre-perihelion) and C/2004 B1 (LINEAR) (2005 October 15.22 UT, r_h = 2.21 AU pre-perihelion and 2006 May 16.22 UT, r_h = 2.06 AU post-perihelion)…
Activity of most comets near the Sun is dominated by sublimation of frozen water, the most abundant ice in comets. Some comets, however, are active well beyond the water-ice sublimation limit of ~3 AU. Three bodies dominate the…
The hydrogen isotopic (D/H) ratio reflects the global cycling and evolution of water on Earth as it fractionates through planetary processes. We model the water cycle taking seafloor hydrothermal alteration, chemical alteration of…
In comets the atomic oxygen green to red-doublet emission intensity ratio (G/R ratio) of 0.1 has been used to confirm H$_2$O as the parent species producing oxygen emission lines. The larger ($>$0.1) value of G/R ratio observed in a few…
The 16OH/18OH and OD/OH isotope ratios are measured in the Oort-Cloud comet C/2002 T7 (LINEAR) through ground-based observations of the OH ultraviolet bands at 3063 A (0,0) and 3121 A (1,1) secured with the Very Large Telescope (VLT)…
Aims. Understanding the activity is vital for deciphering the structure, formation, and evolution of comets. We investigate models of cometary activity by comparing them to the dynamics of 67P/Churyumov-Gerasimenko. Methods. We matched…
The composition of cometary ices provides key information on the thermal and chemical properties of the outer parts of the protoplanetary disk where they formed 4.6 Gy ago. This chapter reviews our knowledge of composition of cometary comae…
Cometary activity is a manifestation of sublimation-driven processes at the surface of nuclei. However, cometary outbursts may arise from other processes that are not necessarily driven by volatiles. In order to fully understand nuclear…
The abundance of deuterium in giant planet atmospheres provides constraints on the reservoirs of ices incorporated into these worlds during their formation and evolution. Motivated by discrepancies in the measured deuterium-hydrogen ratio…
A fundamental question in cometary science is whether the different dynamical classes of comets have different chemical compositions, which would reflect different initial conditions. From the ground or Earth orbit, radio and infrared…
We investigate the evolution of the deuterium-to-hydrogen (D/H) mass ratio driven by EUV photoevaporation of hydrogen-rich atmospheres of close-in sub-Neptunes around solar-type stars. For the first time, the diffusion-limited approach in…
High-resolution far-infrared and sub-millimetre spectroscopy of water lines is an important tool to understand the physical and chemical properties of cometary atmospheres. We present observations of several rotational ortho- and para-water…
The ratios of the three stable oxygen isotopes 16O, 17O and 18O on Earth and, as far as we know in the solar system, show variations on the order of a few percent at most, with a few outliers in meteorites. However, in the interstellar…
The chemical composition of comets is frequently assumed to be directly provided by the observations of the abundances of volatile molecules in the coma. The present work aims to determine the relationship between the chemical composition…
Organic matter and hydrous silicates are intimately mixed in the matrix of chondrites and in-situ determination of their individual D/H ratios is therefore challenging. Nevertheless, the D/H ratio of each pure component in this mixture…
Remote sensing data from orbiter missions have proposed that ground ice may currently exist on Mars, although the volume is still uncertain. Recent analyses of Martian meteorites have suggested that the water reservoirs have at least three…