New Models of Water Delivery To Earth: The Effects of Ice Longevity and Collisional Water Transport
- Autor(en)
- Thomas Maindl, Nader Haghighipour
- Abstrakt
It is widely accepted that the vast majority of Earth's water was delivered to its accretion zone by water-carrying planetesimals and planetary embryos from the outer regions of the asteroid belt while Earth was still forming. Modern simulations of the formation of terrestrial planets show this process with high resolution. However, their treatment of the actual delivery of water is still rudimentary assuming that a water-carrying object will maintain all its water content during its journey from its original orbit to the accretion zone of Earth. Models of the ice longevity have, however, shown that the water-ice may not stay intact, and asteroids and planetary embryos may lose some of their original water in form of ice sublimation during the dynamical evolution of these bodies. Also, collisions among these bodies while on their journey to Earth's accretion zone will result in the loss of large amounts of their water. These effects could be especially important during the formation of terrestrial planets as this process takes tens to hundreds of millions of years. We have developed a more accurate model in which the sublimation of ice during the process of the scattering of icy asteroids and planetary embryos into the accretion zone of Earth is taken into account. Our model includes two different modes of handling ice sublimation, one for sub-surface water and one for deeper ice. We also estimate water loss and retention during collisions which depends on the physical and dynamical parameters of the impacts. The results of our simulations put stringent constraints on the initial water distribution in the protoplanetary disk, the location of snowline, and the contribution of water from the primordial nebula to the final water budget of Earth. In this poster, we will present the results of our new simulations and discuss their implications for models of solar system formation and dynamics.
- Organisation(en)
- Institut für Astrophysik
- Externe Organisation(en)
- University of Hawaii
- Publikationsdatum
- 10-2016
- ÖFOS 2012
- 103003 Astronomie, 103004 Astrophysik
- Link zum Portal
- https://ucrisportal.univie.ac.at/de/publications/3af2d805-dcb4-465f-ac16-475f0279ecec