eccentricity about x-x
71Timekeeping on Mars — Various schemes have been used or proposed to keep track of time and date on the planet Mars independently of Earth time and calendars. Mars has an axial tilt and a rotation period similar to those of Earth. Thus it experiences seasons of spring …
72comet — cometary /kom i ter ee/, cometic /keuh met ik/, cometical, adj. cometlike, adj. /kom it/, n. Astron. a celestial body moving about the sun, usually in a highly eccentric orbit, consisting of a central mass surrounded by an envelope of dust and… …
73Kuiper belt — Known objects in the Kuiper belt, derived from data from the Minor Planet Center. Obje …
74HD 209458 b — Extrasolar planet List of extrasolar planets Size comparison of HD 209458 b with Jupiter. Parent star Star …
75Io (moon) — ] Unlike most satellites in the outer Solar System (which have a thick coating of ice), Io is primarily composed of silicate rock surrounding a molten iron or iron sulfide core. Most of Io s surface is characterized by extensive plains coated… …
76Kozai mechanism — In celestial mechanics, the Kozai mechanism is a secular perturbative effect on certain orbits. It causes changes in the eccentricity and the inclination of the orbit of the perturbed body to be periodic and synchronized, and also causes… …
77Elliptic orbit — A small body in space orbits a large one (like a planet around the sun) along an elliptical path, with the large body being located at one of the ellipse foci …
78North African climate cycles — have a unique history that can be traced back millions of years. The cyclic climate pattern of the Sahara is characterized by significant shifts in the strength of the North African Monsoon. When the North African Monsoon is at its strongest… …
79Geostationary orbit — Geostationary orbit.To an observer on the rotating Earth (fixed point on the Earth), the satellite appears stationary in the sky. A red satellite is also geostationary above its own point on Earth. Top Down View …
80Binary star — For the hip hop group, see Binary Star (band). Hubble image of the …
