Posted on 03/29/2006 10:21:37 AM PST by SunkenCiv
For scientists who spend time thinking about how planets form, life would be simpler if gas giants like Jupiter and Saturn didnt exist.
According to the standard model of planet formation, called "core accretion," planets form over millions of years as enormous blocks of rock and ice smash together to form planetary embryos, called "protoplanets," and eventually full-fledged planets.
Most scientists agree that core accretion is how terrestrial planets such as Earth and Mars were created, but the model cant convincingly explain how gas giant planets like Jupiter and Saturn came to be.
One major problem is that developing gas giants through core accretion takes too long. According to the best current models, the process requires several million yearslonger than the typical observed lifetime of the stellar gas disks from which planets are born.
(Excerpt) Read more at news.yahoo.com ...
There is a book called "Rare Earth" that explains this.
We're going on a planet hunt
EurekAlert | 04/05/06 | Claire Bowles
Posted on 04/05/2006 10:53:38 PM EDT by KevinDavis
http://www.freerepublic.com/focus/f-bloggers/1610016/posts
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.