Stability of the Solar System that keeps the far side of the Moon away from the Earth. Mercury is in a 3:2 spin–orbit resonance. The planets' orbits are chaotic over longer timescales, such that the whole Solar System possesses a Lyapunov time in the range of 2–230 million years. In all cases this means that the position of a planet along its orbit ultimately becomes impossible to predict with any certainty (so, for example, the timing of winter and summer become uncertain), but in some cases the orbits themselves may change dramatically. Such chaos manifests most strongly as changes in eccentricity, with some planets' orbits
Terra: The Nature of Our World previous podcasts. LifeOnTERRA's ("TERRA: The Nature of Our World's") website http://www.lifeonterra.com/ was launched in October 2006. This site features a new biweekly episode ready for viewing and downloading, along with its 8 seasons of documentary offerings. All videos are offered as QuickTime (.m4v). The current website was launched in September 2013 and includes many features from the previous website, with a fresh new look. The website was designed and built by Jeff Reed. Hosting for the Videos is provided by Vimeo. As - TERRA: The Nature of Our World-www.lifeonterra.com is the winner of two 2013 WEBBY awards, the People's Voice