Constraining planetesimal-formation models by comet observations

• Applicant: Professor Dr. Jürgen Blum
• Subject Area: Astrophysics and Astronomy
• Term: from 2020 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 436344287

The two main planetesimal-formation scenarios – the gravoturbulent collapse of a pebble cloud and the collisional mass accretion – shall be characterized with respect to the predicted physical properties of the resulting planetesimals. We will determine and quantify as many as possible planetesimal properties and study whether and to which extent evolutionary processes might have altered these properties between planetesimal formation and today in those regions of the protoplanetary disk and the Kuiper Belt from which short-period comets originate. In parallel, we will identify useable observables and tools from observations of and missions to comets to determine the equivalent physical properties of cometary nuclei. Finally, we will discuss whether and under which conditions an unambiguous determination of the formation scenario of planetesimals is at all feasible with current and anticipated future observations of comets and cometary nuclei. The proposed project encompasses numerous collaborations with renowned international colleagues on planetesimal formation and evolutions as well as with experts on comet observations and modelling. On top of that, an international workshop on planetesimal formation is planned that will be organized as part of this project.

• DFG Programme: Research Grants