Semimajor Axis

Definition: Semimajor Axis

Semimajor Axis

Noun

1. One-half the major axis of an ellipse; the distance from the center of an ellipse to one end.

Specialty Definitions: Semimajor Axis

Domain	Definitions
Aerospace	One-half the longest diameter of an ellipse.Symbol a. (references)
Physics	The semimajor axis of an ellipse (e.g. a planetary orbit) is 1/2 the length of the major axis which is a segment of a line passing thru the foci of the ellipse with endpoints on the ellipse itself. The semimajor axis of a planetary orbit is also the average distance from the planet to its primary. The periapsis and apoapsis distances can be calculated from the semimajor axis and the eccentricity byrp = a(1-e) and ra = a(1+e). (references)
Space	A property of an ellipse, equal to half its greatest width, as measured along the line connecting its two foci. The semi-major axis of an orbital ellipse is one of the "orbital elements" characterizing it, and is directly related to the energy of the motion. (references)
Source: compiled by the editor from various references; see credits.

Specialty Definition: Semimajor axis

In an elliptical shape, the major axis is the longest line that runs through the center of the ellipse, its ends being at the widest points of the shape. The semimajor axis is one half of the major axis; running from the center, through a focus, and to the edge of the ellipse.

For a more in-depth explanation, see ellipse. Also contrast with semiminor axis.

Anagrams: Semimajor Axis

Scrabble® Enable2K-Verified Anagrams
	Words within the letters "a-a-e-i-i-j-m-m-o-r-s-s-x"
	-4 letters: isomerism, maximises.
	-5 letters: maximise, misraise.
Source: compiled by the editor from various references; see credits. SCRABBLE® is a registered trademark. All intellectual property rights in and to the game are owned in the U.S.A and Canada by Hasbro Inc., and throughout the rest of the world by J.W. Spear & Sons Limited of Maidenhead, Berkshire, England, a subsidiary of Mattel Inc. Mattel and Spear are not affiliated with Hasbro.