Search Publications
Report of the IAU Working Group on Cartographic Coordinates and Rotational Elements: 2015
Oberst, J.; A'Hearn, M. F.; Klioner, S. A. +15 more
This report continues the practice where the IAU Working Group on Cartographic Coordinates and Rotational Elements revises recommendations regarding those topics for the planets, satellites, minor planets, and comets approximately every 3 years. The Working Group has now become a "functional working group" of the IAU, and its membership is open to…
Cometary Dust
Langevin, Yves; Thomas, Nicolas; Agarwal, Jessica +11 more
This review presents our understanding of cometary dust at the end of 2017. For decades, insight about the dust ejected by nuclei of comets had stemmed from remote observations from Earth or Earth's orbit, and from flybys, including the samples of dust returned to Earth for laboratory studies by the Stardust return capsule. The long-duration Roset…
Water Reservoirs in Small Planetary Bodies: Meteorites, Asteroids, and Comets
Altwegg, Kathrin; Alexander, Conel M. O'D.; McKeegan, Kevin D.
Asteroids and comets are the remnants of the swarm of planetesimals from which the planets ultimately formed, and they retain records of processes that operated prior to and during planet formation. They are also likely the sources of most of the water and other volatiles accreted by Earth. In this review, we discuss the nature and probable origin…
The ALMA-PILS survey: the sulphur connection between protostars and comets: IRAS 16293-2422 B and 67P/Churyumov-Gerasimenko
van Dishoeck, Ewine F.; Drozdovskaya, Maria N.; Jørgensen, Jes K. +9 more
The evolutionary past of our Solar system can be pieced together by comparing analogous low-mass protostars with remnants of our Protosolar Nebula - comets. Sulphur-bearing molecules may be unique tracers of the joint evolution of the volatile and refractory components. ALMA Band 7 data from the large unbiased Protostellar Interferometric Line Sur…
Catastrophic disruptions as the origin of bilobate comets
Richardson, Derek C.; Jutzi, Martin; Michel, Patrick +3 more
Several comets observed at close range have bilobate shapes1, including comet 67P/Churyumov-Gerasimenko (67P/C-G), which was imaged by the European Space Agency's Rosetta mission2,3. Bilobate comets are thought to be primordial because they are rich in supervolatiles (for example, N2 and CO) and have a low bulk den…
Krypton isotopes and noble gas abundances in the coma of comet 67P/Churyumov-Gerasimenko
Mall, Urs; Bar-Nun, Akiva; De Keyser, Johan +24 more
The ROSINA mass spectrometer DFMS on board ESA's Rosetta spacecraft detected the major isotopes of the noble gases argon, krypton, and xenon in the coma of comet 67P/Churyumov-Gerasimenko. Earlier, it has been shown that xenon exhibits an isotopic composition distinct from anywhere else in the solar system. However, argon isotopes, within error, w…
Local growth of dust- and ice-mixed aggregates as cometary building blocks in the solar nebula
Blum, J.; Lacerda, P.; Lorek, S.
Context. Comet formation by gravitational instability requires aggregates that trigger the streaming instability and cluster in pebble-clouds. These aggregates form as mixtures of dust and ice from (sub-)micrometre-sized dust and ice grains via coagulation in the solar nebula. Aim. We investigate the growth of aggregates from (sub-)micrometre-size…
Thermal inertia and roughness of the nucleus of comet 67P/Churyumov-Gerasimenko from MIRO and VIRTIS observations
Jorda, L.; Kührt, E.; Mottola, S. +17 more
Aims: Using data from the Rosetta mission to comet 67P/Churyumov-Gerasimenko, we evaluate the physical properties of the surface and subsurface of the nucleus and derive estimates for the thermal inertia (TI) and roughness in several regions on the largest lobe of the nucleus.
Methods: We have developed a thermal model to compute the tem…
Plasma source and loss at comet 67P during the Rosetta mission
Altwegg, K.; Carr, C.; Henri, P. +10 more
Context. The Rosetta spacecraft provided us with a unique opportunity to study comet 67P/Churyumov-Gerasimenko (67P) from a close perspective and over a 2-yr time period. Comet 67P is a weakly active comet. It was therefore unexpected to find an active and dynamic ionosphere where the cometary ions were largely dominant over the solar wind ions, e…
Tensile strength of 67P/Churyumov-Gerasimenko nucleus material from overhangs
Jorda, L.; Lara, L. M.; Bertaux, J. -L. +52 more
We directly measured twenty overhanging cliffs on the surface of comet 67P/Churyumov-Gerasimenko extracted from the latest shape model and estimated the minimum tensile strengths needed to support them against collapse under the comet's gravity. We find extremely low strengths of around 1 Pa or less (1 to 5 Pa, when scaled to a metre length). The …