e/Distance of closest approach of ellipses and ellipsoids

Information
has gloss	eng: The distance of closest approach of two objects is the distance between their centers when they are externally tangent. The objects may be geometric shapes or physical particles with well defined boundaries. The distance of closest approach is sometimes referred to as the contact distance.
lexicalization	eng: Distance of closest approach of ellipses and ellipsoids
instance of	(noun) (geometry) a curve generated by the intersection of a plane and a circular cone conic, conic section

Media
media:img	Ellipses.png