tag:blogger.com,1999:blog-378357358243436521.post4501423754493468699..comments2024-03-28T03:18:40.051-04:00Comments on Life, Unbounded: The fountains of EarthAnonymoushttp://www.blogger.com/profile/01991701536947708899noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-378357358243436521.post-5025603669035920252010-05-17T11:22:25.648-04:002010-05-17T11:22:25.648-04:00It's partly a question of energetics. A big pl...It's partly a question of energetics. A big planet like the Earth is formed from the agglomeration of a *lot* of stuff (it would take about 1 trillion kilometer sized objects to make the Earth). These pieces collide/fragment/stick over ten million years or so. The forming planet melts through due to both radioactive decay (more prevalent 4 billion years ago) and the energy from all this colliding material. Hence retaining volatiles (water) can be difficult. Also, water only freezes out into solid form quite a distance away from the proto-Sun during planet formation. So while comets and some asteroids have a large solid water component, a planet like the Earth, forming much closer to the proto-Sun need *not* have much water - unless material from further out in the system is involved in its formation...and hence the discussion of when and from where the Earth got its water.Anonymoushttps://www.blogger.com/profile/01991701536947708899noreply@blogger.comtag:blogger.com,1999:blog-378357358243436521.post-77555052692792061512010-05-17T09:20:44.367-04:002010-05-17T09:20:44.367-04:00I don't get this. If water can form on comets,...I don't get this. If water can form on comets, asteroids, and other proto-planets, why not on Earth as it formed in the same way? Painted on? Implanted? Why does this qustion even come up?Davidhttp://inyostudio.comnoreply@blogger.com