relative orbit
41Uranus — /yoor euh neuhs, yoo ray /, n. 1. Astron. the planet seventh in order from the sun, having an equatorial diameter of 32,600 miles (56,460 km), a mean distance from the sun of 1,784 million miles (2,871 million km), a period of revolution of 84.07 …
42eye, human — ▪ anatomy Introduction specialized sense organ capable of receiving visual images, which are then carried to the brain. Anatomy of the visual apparatus Structures auxiliary to the eye The orbit The eye is protected from mechanical injury… …
43gravitation — gravitational, adj. gravitationally, adv. /grav i tay sheuhn/, n. 1. Physics. a. the force of attraction between any two masses. Cf. law of gravitation. b. an act or process caused by this force. 2. a sinking or falling …
44Earth Sciences — ▪ 2009 Introduction Geology and Geochemistry The theme of the 33rd International Geological Congress, which was held in Norway in August 2008, was “Earth System Science: Foundation for Sustainable Development.” It was attended by nearly… …
45Mathematics and Physical Sciences — ▪ 2003 Introduction Mathematics Mathematics in 2002 was marked by two discoveries in number theory. The first may have practical implications; the second satisfied a 150 year old curiosity. Computer scientist Manindra Agrawal of the… …
46Physical Sciences — ▪ 2009 Introduction Scientists discovered a new family of superconducting materials and obtained unique images of individual hydrogen atoms and of a multiple exoplanet system. Europe completed the Large Hadron Collider, and China and India took… …
47Outer billiard — Outer Billiards is a dynamical system based on a convex shape in the plane. Classically, this system is defined for the Euclidean plane but one can also consider the system in the hyperbolic plane or in other spaces that suitably generalize the… …
48Mars — This article is about the planet. For other uses, see Mars (disambiguation) …
49Alpha Centauri — This article is about α Centauri . For a Centauri , see V761 Centauri. For A Centauri , see A Centauri. For other uses, see Alpha Centauri (disambiguation). Alpha Centauri A[1]/B[2] …
50Spacecraft propulsion — A remote camera captures a close up view of a Space Shuttle Main Engine during a test firing at the John C. Stennis Space Center in Hancock County, Mississippi Spacecraft propulsion is any method used to accelerate spacecraft and artificial… …
