the ascending node
41Geometric albedo — The geometric albedo of an astronomical body is the ratio of its actual brightness at zero phase angle (i.e. as seen from the light source) to that of an idealized flat, fully reflecting, diffusively scattering (Lambertian) disk with the same… …
42eclipse — eclipser, n. /i klips /, n., v., eclipsed, eclipsing. n. 1. Astron. a. the obscuration of the light of the moon by the intervention of the earth between it and the sun (lunar eclipse) or the obscuration of the light of the sun by the intervention …
43May 2069 lunar eclipse — Total Lunar Eclipse May 6, 2069 The moon passes west to east (right to left) across the Earth s umbral shadow, shown in hourly intervals. Series (and member) 132 (33 of 71) Duration (hr:mn:sc) Totality …
44Orbital elements — are the parameters required to uniquely identify a specific orbit. In celestial mechanics these elements are generally considered in classical two body systems, where a Kepler orbit is used (derived from Newton s laws of motion and Newton s law… …
45December 2010 lunar eclipse — Total lunar eclipse 2010/12/21 [1] Saros (member) 125 (48) Recent <S <T < > T> S> …
46Sun-synchronous orbit — Diagram showing the orientation of a Sun synchronous orbit (green) in four points of the year. A non sun synchronous orbit (magenta) is also shown for reference A Sun synchronous orbit (sometimes called a heliosynchronous orbit) is a geocentric… …
47Month — For the Egyptian hawk god, see Monthu. A month is a unit of time, used with calendars, which was first used and invented in Mesopotamia, as a natural period related to the motion of the Moon; month and Moon are cognates. The traditional concept… …
48Pluto — This article is about the dwarf planet. For other uses, see Pluto (disambiguation). Pluto   …
49Molniya orbit — For other uses, see Molniya (disambiguation). Figure 1: The Molniya orbit. Usually the period from perigee + 2 hours to perigee + 10 hours is used to transmit to the northern hemisphere Molniya orbit is a type of highly elliptical orbit with an… …
50Orbital perturbation analysis (spacecraft) — Isaac Newton in his Philosophiæ Naturalis Principia Mathematica demonstrated that the gravitational force between two mass points is inversely proportional to the square of the distance between the points and fully solved corresponding two body… …
