celestial horizon

plural of rational horizon

plural of time horizon

A critical area of performance for aircraft detection systems, defined by the distance at which the radar beam rises enough above the Earth's surface to make detection of a target at low level impossible.

plural of radar horizon

The angle of the horizon below the level of the eye.

plural of Cauchy horizon

(physics) A light-like boundary of the domain of validity of a Cauchy problem. One side of the horizon contains closed space-like geodesics and the other side contains closed time-like geodesics.

A deep in Tonga Trench, Pacific Ocean; the second deepest place on Earth, and deepest part of the Tonga Trench.

plural of marker horizon