- It has long been thought that embryos at 1AU were dry.
- Water came from near or beyond the snow-line.
- Convenient to divide this into three sources:
- Comets (~%50 ice) during Oort cloud formation. (Levison et al. 2001)
- Asteroids (Carbonaceous chondrites contain ~ 10% water).
. Most of our systems have big gaps between terrestrial and giant planets
- Planetary embryo(s) from asteroid belt (Morbidelli et al. 2000).
- Not all terrestrial planets are wet due to small number statistics.
May explain Venus.
Extremes from our systems: (preliminary results)
- This system is dry.
Outer regions cleared before terrestrial planets form.
- The blue planet is very wet.
- Indeed, this planet accreted 10 Oceans of water from comets alone!