Although the Moon is Earth's only natural satellite, there are a number of near-Earth objects (NEOs) with orbits that are in resonance with Earth. These have been called, inaccurately but provocatively, second, third or other moons of Earth. NEOs include quasi-satellites that orbit the Sun in resonance with Earth, which appear to orbit a point other than Earth itself, such as the orbital path of the NEO asteroid 3753 Cruithne.
Definition of CONVERGENCE. 1. : the act of converging and especially moving toward union or uniformity; especially: coordinated movement of the two eyes so that the image of a single point is formed on corresponding retinal areas.
Definition. The Inter Tropical Convergence Zone, or ITCZ, is a belt of low pressure which circles the Earth generally near the equator where the trade winds of the Northern and Southern Hemispheres come together. It is characterised by convective activity which generates often vigorous thunderstorms over large areas.