marking the time when the sun is at the north most point from the celestial equator occurring around June 21
the obscuring of the light of the moon by the intervention of the earth between it and the sun, a lunar eclipse, or the obscuring of the light of the sun by the intervention of the moon between it and a point on the earth, a solar eclipse
used to designate the brightest star in a constellation
any of the nine large heavenly bodies revolving about the sun and shining by reflected light: a similar body revolving about a star other than the sun
a zodiacal constellation between Aries and Aquarius also called the Fishes
the distance traversed by light in one mean solar year, about 5.88 trillion mi. (9.46 trillion km)
the line or circle that forms the apparent boundary between earth and sky.
2.
Astronomy.
a.
the small circle of the celestial sphere whose plane is tangent to the earth at the position of a given observer, or the plane of such a circle (sensible horizon).
b.
Also called rational horizon.the great circle of the celestial sphere whose plane passes through the center of the earth and is parallel to the sensible horizon of a given position, or the plane of such a circle (celestial horizon).
3.
the limit or range of perception, knowledge, or the like.
4.
Usually, horizons.the scope of a person's interest, education, understanding, etc.: His horizons were narrow.
5.
Geology. a thin, distinctive stratum useful for stratigraphic correlation.
sensible horizon (sěn'sə-bəl) Pronunciation Key
The plane of an observer's position lying at a right angle to the line formed by the observer's zenith and nadir. The plane of the sensible horizon is parallel to the plane of the observer's celestial horizon but is tangential to the Earth's surface rather than passing through the Earth's center. Both the celestial and sensible horizons change with the observer's position. Compare celestial horizon.