The project deals with early phases of the Solar System (SS) and extrasolar planetary systems (EPS). The presence of liquid water on the surface of a terrestrial planet is a basic requirement for habitability in planetary systems. The main goal of this project is to investigate where the water came from in the early stages on the one hand; on the other hand, when water was lost during special phases in later stages we need to explain how it was replenished on the surface and, finally, how it could stay liquid on a terrestrial planet in the habitable zone for times up to billions of years. A central question in this respect is the collision behaviour of small bodies regarding their content of water; it has to be modelled with specially designed new and effective computer codes.
The possible water loss of terrestrial planets should be set in context with
- the stellar radiative environment of young active stars (SS and EPS)
- collisions of protoplanetary objects in general (SS and EPS)
- the Late Heavy Bombardement (LHB) and
- the formation of the Moon.
Some main research points of the projects are
- A detailed study of planetary accretion due to protoplanetary collisions with respect to water accumulation and loss via heating processes during and shortly after the collision (impact velocities and masses) in different radiative environments (e.g. distance to the early host star)
- Settling the questions of the importance of prior gas giants regarding the formation of terrestrial planets in early planetary systems with respect to water loss (SS and EPS)
- Loss of water because of the early UVE flux from the host stars (G, K and M stars)
- Loss of water on Earth because of the impact of a Mars-like object triggering the formation of the Moon and net loss or gain of water during the LHB (SS)
- Delivery of water by asteroids from the outer main belt and from Main Belt Comets (MBC) and the scattered disk objects
- Oort cloud comet contribution to the water delivery and organic material in the close stellar environment and the inner SS.