Related papers: CO2-driven surface changes in the Hapi region on C…
The nucleus of comet 67P/Churyumov-Gerasimenko exhibits a broad spectral reflectance feature around 3.2 $\mu$m, which is omnipresent in all spectra of the surface, and whose attribution has remained elusive since its discovery. Based on…
Based on the occurrence rates implied by the discoveries of 1I/`Oumuamua and 2I/Borisov, the forthcoming Rubin Observatory Legacy Survey of Space and Time (LSST) should detect $\ge1$ interstellar objects every year (Hoover et al. 2021). We…
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…
Dust is an important constituent in cometary comae; its analysis is one of the major objectives of ESA's Rosetta mission to comet 67P/Churyumov-Gerasimenko (C-G). Several instruments aboard Rosetta are dedicated to studying various aspects…
We report on the initial analysis of Herschel/HIFI carbon monoxide (CO) observations of the Martian atmosphere performed between 11 and 16 April 2010. We selected the (7-6) rotational transitions of the isotopes ^{13}CO at 771 GHz and…
We use the Mopra radio telescope to test for expansion of the molecular gas associated with the bubble HII region RCW120. A ring, or bubble, morphology is common for Galactic HII regions, but the three-dimensional geometry of such objects…
Context. Breathtaking imagery recorded during the European Space Agency's Rosetta mission confirmed the bilobate nature of comet 67P/Churyumov-Gerasimenko's nucleus. Its peculiar appearance is not unique among comets. The majority of…
The analysis of photometrical observations of comet 29P/Schwassmann-Wachmann 1 is presented. The broadband observations were carried out for 15 nights from 2012 to 2019 at the Lisnyky observational station of Taras Shevchenko National…
There was an unprecedented opportunity to study the inner dust coma environment, where the dust and gas are not entirely decoupled, of comets 45P/Honda-Mrkos-Pajdu\u{s}\'akov\'a (45P/HMP) from Dec. 26, 2016 - Mar. 15, 2017, and 46P/Wirtanen…
Kuiper belt objects, such as Arrokoth, the probable progenitors of short-period comets, formed and evolved at large heliocentric distances, where the ambient temperatures appear to be sufficiently low for preserving volatile ices. By…
The first 1000 km of the ion tail of comet 67P/Churyumov-Gerasimenko were explored by the European Rosetta spacecraft, 2.7 au away from the Sun. We characterised the dynamics of both the solar wind and the cometary ions on the night-side of…
The physical properties of cometary nuclei observed today relate to their complex history and help to constrain their formation and evolution. In this article, we review some of the main physical properties of cometary nuclei and focus in…
We surveyed 23 comets using the Infrared Array Camera on the Spitzer Space Telescope in wide filters centered at 3.6 and 4.5 microns. Emission in the 3.6 micron filter arises from sunlight scattered by dust grains; these images generally…
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…
We present infrared images and spectra of comets 2P/Encke, 67P/Churyumov-Gerasimenko, and C/2001 HT50 (LINEAR-NEAT) as part of a larger program to observe comets inside of 5 AU from the sun with the Spitzer Space Telescope. The nucleus of…
Aims. We aim to determine whether dissociative excitation of cometary neutrals by electron impact is the major source of far-ultraviolet (FUV) emissions at comet 67P/Churyumov-Gerasimenko in the southern hemisphere at large heliocentric…
After coming to rest on the night side of comet 67P/Churyumov-Gerasimenko, the ROLIS camera on-board Rosetta's Philae lander acquired five images of the surface below the lander, four of which were with the aid of LED illumination of…
The aim of this study is first to determine the gravity field of the comet 67P Churyumov-Gerasimenko and second to derive the solar component of the precession rate and nutation coefficients of the spin axis of the comet nucleus, i.e.…
Here, we report the detection of phosphorus and fluorine in solid particles collected from the inner coma of comet 67P/Churyumov-Gerasimenko measured with the COmetary Secondary Ion Mass Analyser (COSIMA) instrument on-board the Rosetta…
Comets are made of volatile and refractory material and naturally experience various degrees of sublimation as they orbit around the Sun. This gas release, accompanied by dust, represents what is traditionally described as activity.…