The impact of neos and their fragments recorded from the ground : ongoing research lines of the spanish fireball network

A continuous monitoring of the night sky all over Spain will be completed in 2009. This involves the recording over a very large surface area of 500,000 km2, but new CCD and video cameras operated by the Spanish Meteor and Fireball Network (SPMN) allows this target to be achieved. Through the use of these new techniques the SPMN can obtain new information regarding the dynamical processes that deliver meteorites to the Earth. It transpires that the main asteroid belt is not the only source of these fireballs, Near Earth Objects (NEOs) and Jupiter Family Comets (JFCs) may also play a role. To obtain more information in this regard, new efforts are needed to compare the orbits of large meteoroids reaching the Earth with those of the members of NEO and JFC populations. By numerically integrating their orbits back in time it may be possible to identify meteoroids delivered by other mechanisms like such as catastrophic disruptions or collisions

Stability Conditions for Permanent Rotations of a Heavy Gyrostat with Two Constant Rotors

In this paper, we consider the motion of an asymmetric heavy gyrostat, when its center of mass lies along one of the principal axes of inertia. We determine the possible permanent rotations and, by means of the Energy-Casimir method, we give sufficient stability conditions. We prove that there exist permanent stable rotations when the gyrostat is oriented in any direction of the space, by the action of two spinning rotors, one of them aligned along the principal axis, where the center of mass lies. We also derive necessary stability conditions that, in some cases, are the same as the sufficient ones

Stability of equilibria for 2D resonant hamiltoian systems: a geometrical approach

The stability of an equilibrium point of a 2-D Hamiltonian system, in the presence of resonances, is decided by means of a geometrical criterium, when the corresponding quadratic part is not sign defined. It is proven that this method is the geometrical counterpart of a theorem of Cabral and Meyer which constitutes an extension of the Arnold's theorem

Relative equilibria and bifurcations in a 2-D Hamiltonian system in resonance 1:p

In this work, we focus on a Hamiltonian system with two degrees of freedom whose normal form in a neighborhood of the equilibrium solution up to order two, corresponds to a subtraction of two harmonic oscillators in resonance 1:p, with p an odd number. We introduce appropriate coordinates in the reduced phase space in order to study the existence of relative equilibria and bifurcations in terms of the free parameters of the system. We do this for to the simplest case, the resonance 1:3, and then we comment how these results can be extended for a resonance 1:p with p an odd number