Semi-major and semi-minor axes
(Redirected from Semi-major axis)
In geometry, the semi-major axis is the distance from the center of an ellipse to the farthest point on the perimeter of the ellipse. The semi-major axis is half of the major axis, which goes all the way across the ellipse at the widest part. The semi-minor axis is a line segment that is at 90 degrees with the semi-major axis. For the circle, the lengths of the semi-axes are both equal to the radius.
Semi-major And Semi-minor Axes Media
Log-log plot of period T vs semi-major axis a (average of aphelion and perihelion) of some Solar System orbits (crosses denoting Kepler's values) showing that a3 / T2 is constant (green line)
