[meteorite-list] Jupiter Not The Planetary Shield We Thought It Was

[Ron Baalke]

http://newuniversedaily.com/2016/02/06/jupiter-not-the-planetary-shield-we-thought-it-was

Jupiter Not The Planetary Shield We Thought It Was
New Universe Daily
February 6, 2016

The "Jupiter as a shield" theory implies that the planets massive 
gravity protects Earth from comet impacts by attracting most of the action 
before it reaches Earth, but new research says that hypothesis is incorrect.

Models formulated by Dr. Kevin Grazier at NASA's Jet Propulsion Laboratory 
suggest that not only did Jupiter not protect us, but that it, along with 
Saturn likely played a vital roll in shuttling material into Earths orbit. 
The findings were published in the journal Astrobiology.

Grazier, along with his team, created models simulating the evolution 
of particles in the orbital gap between the two gas giant planets. The 
simulations shows that Jupiter and Saturn team up to deflect a significant 
portion of those particles into the inner solar system.

Despite Jupiter losing the protector label, scientists still think that 
a solar system with one or more planets similar to Jupiter, located beyond 
the region of the habitable zone, is beneficial for the development of 
life. It's likely that Saturn and Jupiter played a critical role in 
shuttling exotic material from the outer solar system that helped support 
life here on Earth.

"In an unprecedented effort to solve the riddle as to whether jovian 
bodies shield habitable planets from impacts catastrophic to life, Dr. 
Grazier presents a modeling study that speaks to the incredible complexity 
of planetisimal evolution in the Solar System," said Dr. Sherry Cady, 
Editor-in-Chief of Astrobiology. 

"In this paper, we learn that the overly simplistic 'Jupiter as shield' 
concept is a thing of the past, and future research in this area will 
require the continued use of the kinds of robust simulation strategies 
so effectively employed in Dr. Grazier's work."