Maculae (mak´u-lē). Dark spots on the surfaces of sun and moon, and on some of the planets.
Moon. A secondary planet or satellite of the earth, whose light, borrowed from the sun, serves to dispel the darkness of night.
Nadir (nā´dir). The point of the heavens or lower hemisphere directly opposite the zenith.
Neb´ulae (neb´u-lē). Misty appearances among the stars, usually, but not always, resolved by telescope into myriads of small stars.
Nodes (nōdes). The two points in which the orbit of a planet intersects the ecliptic.
Nuta´tion. A vibratory motion of the earth’s axis, arising from periodical fluctuations in the obliquity of the ecliptic.
Occulta´tion. The hiding of a heavenly body from our sight by the intervention of some other of the heavenly bodies.
Or´bit. The path described by a heavenly body in its periodical revolution.
Par´allax. The change of place in a heavenly body in consequence of being viewed from different points.
Penum´bra. A partial shadow or obscurity on the margin of the perfect shadow in an eclipse, or between the perfect shadow, where the light is entirely intercepted, and the full light.