Either of the halves of the major axis of an ellipse.
〔几何〕（椭圆的）半长轴
Example sentencesExamples
The initial covariance matrices of each lander were set to correspond to a 15 by 8 kilometer landing ellipse with a semimajor axis in the East-West direction.
The semimajor axes of an ellipse are the longest lines crossing the area covered by the ellipse, and including the two foci.
To the extent that the parent star's mass is known from its spectrum and luminosity, the periodicity of the Doppler signal yields the planetary orbit's semimajor axis a.
The speed of the satellite is inversely proportional to the square root of the radius of the orbit (or more strictly the semimajor axis of the orbit).
Kepler's third law of planetary motion says that the square of the planet's orbital period is proportional to the cube of its semimajor axis.
Definition of semimajor axis in US English:
semimajor axis
nounˈsemˌī-
Geometry
Either of the halves of the major axis of an ellipse.
〔几何〕（椭圆的）半长轴
Example sentencesExamples
The semimajor axes of an ellipse are the longest lines crossing the area covered by the ellipse, and including the two foci.
The speed of the satellite is inversely proportional to the square root of the radius of the orbit (or more strictly the semimajor axis of the orbit).
The initial covariance matrices of each lander were set to correspond to a 15 by 8 kilometer landing ellipse with a semimajor axis in the East-West direction.
To the extent that the parent star's mass is known from its spectrum and luminosity, the periodicity of the Doppler signal yields the planetary orbit's semimajor axis a.
Kepler's third law of planetary motion says that the square of the planet's orbital period is proportional to the cube of its semimajor axis.