Comments on: Apsidal http://oklo.org/2006/11/07/apsidal/ characterizing planetary systems Sat, 20 Mar 2010 02:18:04 +0000 http://wordpress.org/?v=2.9.2 hourly 1 By: systemic - It won’t last forever… http://oklo.org/2006/11/07/apsidal/comment-page-1/#comment-4827 systemic - It won’t last forever… Mon, 14 Apr 2008 05:47:48 +0000 http://oklo.org/?p=166#comment-4827 [...] I read Laskar’s paper in 1999, shortly after the discovery of the Upsilon Andromedae planetary system spurred me into a crash-course study of orbital dynamics. His calculations seemed to raise some really interesting questions. What is the dynamical mechanism that destabilized the inner Solar System? Was the elevation of Mercury’s eccentricity a consequence of the secular perturbation approach that he applied? Would his bifurcation strategy find a similar result when used with direct numerical integration of the equations of motion? [...] [...] I read Laskar’s paper in 1999, shortly after the discovery of the Upsilon Andromedae planetary system spurred me into a crash-course study of orbital dynamics. His calculations seemed to raise some really interesting questions. What is the dynamical mechanism that destabilized the inner Solar System? Was the elevation of Mercury’s eccentricity a consequence of the secular perturbation approach that he applied? Would his bifurcation strategy find a similar result when used with direct numerical integration of the equations of motion? [...]

]]> By: systemic - stability http://oklo.org/2006/11/07/apsidal/comment-page-1/#comment-929 systemic - stability Wed, 17 Jan 2007 00:46:52 +0000 http://oklo.org/?p=166#comment-929 [...] Although we don’t expect to see orbital instabilities play out on our watch, it’s nevertheless likely that planet-planet interactions and their associated instabilities have played an important past role in sculpting the systems that we now observe. For example, Eric Ford and his collaborators have published a highly plausible theory for the formation of the Upsilon Andromedae planetary system that involves a dramatic instability. In their scenario, the system starts out with four planets, and eventually ejects one of them. The outer two survivors are left stunned and reeling, and the dynamical imprint of the disaster survives to the present day. They’ve made an engaging animation (available here) that shows the action blow-by-blow. [...] [...] Although we don’t expect to see orbital instabilities play out on our watch, it’s nevertheless likely that planet-planet interactions and their associated instabilities have played an important past role in sculpting the systems that we now observe. For example, Eric Ford and his collaborators have published a highly plausible theory for the formation of the Upsilon Andromedae planetary system that involves a dramatic instability. In their scenario, the system starts out with four planets, and eventually ejects one of them. The outer two survivors are left stunned and reeling, and the dynamical imprint of the disaster survives to the present day. They’ve made an engaging animation (available here) that shows the action blow-by-blow. [...]

]]> By: andy http://oklo.org/2006/11/07/apsidal/comment-page-1/#comment-435 andy Tue, 07 Nov 2006 14:50:35 +0000 http://oklo.org/?p=166#comment-435 "Fourpiter" seems to be located near the outer edge of the habitable zone of Upsilon Andromedae, so maybe if it has large moons they could have earthlike environments. Presumably a clsoe gravitational encounter to another jovian planet wouldn't be too healthy for forming moons there. How close an encounter to "Outtathere" would be required, and could any large moons of "Fourpiter" survive the gravitational scrambling? Also, could such encounters significantly tip the rotation axis of "Fourpiter"? “Fourpiter” seems to be located near the outer edge of the habitable zone of Upsilon Andromedae, so maybe if it has large moons they could have earthlike environments. Presumably a clsoe gravitational encounter to another jovian planet wouldn’t be too healthy for forming moons there.

How close an encounter to “Outtathere” would be required, and could any large moons of “Fourpiter” survive the gravitational scrambling? Also, could such encounters significantly tip the rotation axis of “Fourpiter”?

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