Jupiter—Friend or Foe?

International Journal of Astrobiology 7

By J. Horner and B.W. Jones

Presentation by Drew Carlson

Why Jupiter?

Massive Affects orbital patterns

of smaller bodies Believed to reduce

impact incidence on earth

Ejects debris Necessary for life?

Asteroid Belt

Placement not coincidental

Not as friendly on second thought?

Can alter near-distance (Kuiper belt) comets for the worse

Can affect asteroid orbits for the worse

Extinctions not life-extinguishing

Modeling experiment

Keep the rest of the solar system constant Alter Jupiter's mass Use the Hill Radius Equation to determine pulls Some Randomness in generating asteroids Problems?

Under the Hood

Hill Radius:

(Jovian) Resonance: Objects with simple numeric ratios produce unique behavior

Results from these effects

Changing the mass causes resonance to “sweep” through the belt

Kirkwood Gaps move Different distributions Concluded to be the

biggest factor in affecting impact rates

Overall Results

Large Jupiters means more ejected debris

Small Jupiters pull less asteroids into threatening orbits

Middle is the worst of both worlds

How conclusive?

Application

Which exosolar systems to look at

What systems would be acceptable for life

Must acknowledge limitations

Questions?

Picture Sources

http://brianlean.wordpress.com/2008/10/15/cretaceous-period-the-end-of-the-dinosaurs/

http://www.mhs-science.org.uk/asteroid_belt.htm

http://library.thinkquest.org/TQ0313199/comets.htm

http://en.wikipedia.org/wiki/Hill_sphere

http://keetsa.com/blog/the-environment/deforestation/forget-being-eco-friendly-we-are-all-going-to-die/

http://science.howstuffworks.com/asteroid-belt.htm

http://worldofweirdthings.com/2010/02/19/should-we-spread-our-germs-across-space/http://www.thetechherald.com/article.php/201022/5694/Astronomers-watch-as-Jupiter-slammed-by-space-debris