The Space Review: Review: From Dust to Life January 14, 2014Posted by sandyclaus in Drake Revisited.
The current state of those studies is ably explained in From Dust to Life, a book by planetary scientist John Chambers and science writer Jacqueline Mitton. The duo examine the history and current state of knowledge of the formation of our solar system, stretching from astrophysics (the formation of our Sun and the age of the universe) to astrobiology (the formation of life on Earth.) The bulk of the book, though, looks at the formation of the planets, moons, and small bodies in the solar system, and how the solar system achieved its present form.
One key takeaway from this book is that planet formation was a lot more dynamic than the simplistic models taught even in the relatively recent past. In particular, scientists now believe that planets migrated through the solar system during its formation, something illustrated by the discovery of other solar systems that have, for example, Jupiter-sized worlds closely orbiting stars. In our solar system, the “Grand Tack” model has Jupiter migrating closer to the Sun, approaching 1.5 astronomical units (AU) from the Sun before the presence of Saturn caused Jupiter to reverse direction back out to its current location at 5.2 AU. That inward and outward migration could explain the relatively small size of Mars and also clear out most of the material in the main asteroid belt.