333 citations · 3k across the 58 of their papers we have counts for
49 papers · 1 filter
Simulation and experiment of gas diffusion in a granular bed
Carsten Güttler, Martin Rose, Holger Sierks +6
The diffusion of gas through porous material is important to understand the physical processes underlying cometary activity. We study the diffusion of a rarefied gas (Knudsen regim…
A quantitative description of comet 67P's dust and gas production remains enigmatic
Dorothea Bischoff, Christian Schuckart, Nicholas Attree +2
The mechanism of dust emission from a cometary nucleus is still an open question and thermophysical models have problems reproducing outgassing and dust productions rates simultane…
Comets and Planetesimal Formation
Jacob B. Simon, Jürgen Blum, Til Birnstiel +1
In this chapter, we review the processes involved in the formation of planetesimals and comets. We will start with a description of the physics of dust grain growth and how this is…
Sub-mm/mm optical properties of real protoplanetary matter derived from Rosetta/MIRO observations of comet 67P
Johanna Bürger, Thilo Glißmann, Anthony Lethuillier +6
Optical properties are required for the correct understanding and modelling of protoplanetary and debris discs. By assuming that comets are the most pristine bodies in the solar sy…
Formation of Comets
Jürgen Blum, Dorothea Bischoff, Bastian Gundlach
Questions regarding how primordial or pristine the comets of the solar system are have been an ongoing controversy. In this review, we describe comets' physical evolution from dust…
Are there any pristine comets? Constraints from pebble structure
Uri Malamud, Wolf A. Landeck, Dorothea Bischoff +4
We show that if comets (or any small icy planetesimals such as Kuiper belt objects) are composed of pebble piles, their internal radiogenic as well as geochemical heating results i…
Collisional properties of cm-sized high-porosity ice and dust aggregates and their applications to early planet formation
Rainer R. Schräpler, Wolf A. Landeck, Jürgen Blum
In dead zones of protoplanetary discs, it is assumed that micrometre-sized particles grow Brownian, sediment to the midplane and drift radially inward. When collisional compaction…
Learning about comets from the study of mass distributions and fluxes of meteoroid streams
Josep M. Trigo-Rodríguez, Jürgen Blum
Meteor physics can provide new clues about the size, structure, and density of cometary disintegration products, establishing a bridge between different research fields. From meteo…
Observations of the long-lasting activity of the distant Comets 29P Schwassmann-Wachmann 1, C/2003 WT42 (LINEAR) and C/2002 VQ94 (LINEAR)
Oleksandra Ivanova, Yury Skorov, Pavlo Korsun +2
We investigated three comets, which are active at large heliocentric distances, using observations obtained at the 6-m BTA telescope (SAO RAS, Russia) in the photometric mode of th…
Comparing the reflectivity of ungrouped carbonaceous chondrites with that of short period comets like 2P/Encke
Safoura Tanbakouei, Josep M. Trigo-Rodriguez, Jurgen blum +2
Aims. The existence of asteroid complexes produced by the disruption of these comets suggests that evolved comets could also produce high-strength materials able to survive as mete…
Activity of (6478) Gault during January 13 - March 28, 2019
Oleksandra Ivanova, Yuri Skorov, Igor Luk'yanyk +5
We present the results of photometric observations of active asteroid (6478) Gault performed at heliocentric distances from 2.46 to 2.30 au and geocentric distances from 1.79 to 1.…
AMBITION -- Comet Nucleus Cryogenic Sample Return (White paper for ESA's Voyage 2050 programme)
D. Bockelée-Morvan, G. Filacchione, K. Altwegg +27
This white paper proposes that AMBITION, a Comet Nucleus Sample Return mission, be a cornerstone of ESA's Voyage 2050 programme. We summarise some of the most important questions s…
Observation of aerodynamic instability in the flow of a particle stream in a dilute gas
Holly L. Capelo, Jan Molacek, Michiel Lambrechts +5
Forming macroscopic solid bodies in circumstellar discs requires local dust concentration levels significantly higher than the mean. Interactions of the dust particles with the gas…
Experiments on cometary activity: ejection of dust aggregates from a sublimating water-ice surface
D. Bischoff, B. Gundlach, M. Neuhaus +1
The gas-driven dust activity of comets is still an unresolved question in cometary science. In the past, it was believed that comets are dirty snowballs and that the dust is ejecte…
The optical characteristics of the dust of sungrazing comet C/2012 S1 (ISON) observed at large heliocentric distances
Oleksandra Ivanova, Volodymyr Reshetnyk, Yury Skorov +7
We present an analysis of the photometric and spectroscopic data of the comet C/2012 S1 (ISON) observed at the heliocentric distances of 6.21÷4.81 AU. The photometric observations…
Asteroid Ryugu Before the Hayabusa2 Encounter
Koji Wada, Matthias Grott, Patrick Michel +31
Asteroid (162173) Ryugu is the target object of Hayabusa2, an asteroid exploration and sample return mission led by Japan Aerospace Exploration Agency (JAXA). Ground-based observat…
Dust evolution in protoplanetary discs and the formation of planetesimals. What have we learned from laboratory experiments?
Jürgen Blum
After 25 years of laboratory research on protoplanetary dust agglomeration, a consistent picture of the various processes that involve colliding dust aggregates has emerged. Beside…
The physics of protoplanetesimal dust agglomerates. X. High-velocity collisions between small and large dust agglomerates as growth barrier
Rainer Schräpler, Jürgen Blum, Sebastiaan Krijt +1
In a protoplanetary disk, dust aggregates in the m to mm size range possess mean collision velocities of 10 to 60 ms with respect to dm- to m-size bodies. We performed la…
Debris Disc Constraints on Planetesimal Formation
Alexander V. Krivov, Aljoscha Ide, Torsten Löhne +2
Two basic routes for planetesimal formation have been proposed over the last few decades. One is a classical "slow-growth" scenario. Another one is particle concentration models, i…
The Physics of Protoplanetesimal Dust Agglomerates. X. Mechanical properties of dust aggregates probed by a solid-projectile impact
H. Katsuragi, J. Blum
Dynamic characterization of mechanical properties of dust aggregates has been one of the most important problems to quantitatively discuss the dust growth in protoplanetary disks.…
Evidence for the formation of comet 67P/Churyumov-Gerasimenko through gravitational collapse of a bound clump of pebbles
Jürgen Blum, Bastian Gundlach, Maya Krause +19
The processes that led to the formation of the planetary bodies in the Solar System are still not fully understood. Using the results obtained with the comprehensive suite of instr…
Micrometer-Sized Water Ice Particles for Planetary Science Experiments: Influence of Surface Structure on Collisional Properties
Sabrina Gärtner, Bastian Gundlach, Thomas F. Headen +7
Models and observations suggest that ice-particle aggregation at and beyond the snowline dominates the earliest stages of planet-formation, which therefore is subject to many labor…
Low-velocity collision behaviour of clusters composed of sub-mm sized dust aggregates
J. Brisset, D. Heißelmann, S. Kothe +2
The experiments presented aim to measure the outcome of collisions between sub-mm sized protoplanetary dust aggregate analogues. We also observed the clusters formed from these agg…
Nanoindenting the Chelyabinsk meteorite to learn about impact deflection effects in asteroids
Carles E. Moyano-Cambero, Eva Pellicer, Josep M. Trigo-Rodríguez +7
The Chelyabinsk meteorite is a highly shocked, low porosity, ordinary chondrite, probably similar to S- or Q-type asteroids. Therefore, nanoindentation experiments on this meteorit…