With the advent of the periscopic sextant, the astrodome became redundant, and further refinements to the instrument, such as a bubble to replace (and eliminate the need for) a visible horizon gave the sextant more versatility. Early long range aircraft were often fitted with an astrodome, a 'bubble' which protruded from the fuselage, in which a navigator could use a hand-held octant to 'shoot' the stars. The advent of air travel brought new challenges to long range navigation. Over time, navigational tools and methodology evolved allowing sailors to reliably find their way across the world's oceans (and return home) and, eventually, the relative position and orientation of various constellations gave way to mathematical (sight reduction) calculation of position based on the use of specific stars or planets.

Early practitioners navigated the sands of the African deserts and oceans between the islands of the South Pacific with nothing more than the stars to guide them. Since the beginnings of recorded history, the human race has been finding its way, in some cases over long distances, by observing the relative positions of the sun, the moon and the stars. Celestial Navigation is navigation by observation of the positions of celestial bodies, inclusive of the sun, moon, planets and certain stars.

Heavenly bodies definition