[DOC] [TLE] Questions on Celestial Phenomena [PAR] (2) Earth (3) zenith (4) NVA (5) Sun. 2. The circle on the celestial sphere midway 
between the north and south celestial poles is the ... The boundary between the 
ground and the sky (i.e., the part of the celestial ... (3) altitude of pole = 90 
degrees - observer's latitude ... Its shadow is shortest at noon (apparent, not by 
the clock). [DOC] [TLE] Celestial Sphere - Jim Kaler [PAR] The latitude of the north pole is 90, that of the equator 0. ... In between is the 
great circle of the horizon, which is the circle on the celestial sphere cut by a ... 
The extension of the Earth's rotation axis to the sky defines the North and South ... 
The circle that runs through the zenith, nadir, NCP, and SCP is the celestial 
meridian. [DOC] [TLE] Lecture 2 [PAR] Point directly overhead is the zenith; Boundary between Earth and sky is the ... 
degrees: with 0 degrees at the equator and the north pole being 90 degrees 
north. ... Ecliptic: the Sun's apparent annual path among the constellations (the 
zodiac)... [DOC] [TLE] Power From The Sun :: Chapter 3 [PAR] Solar altitude, zenith and azimuth angles; Geometric view of sun's path; Daily ... 
Ideally, the meridians 7 degrees on either side of the standard time zone .... This 
is the difference between the local apparent solar time and the local .... earth's 
surface at 90 degrees latitude (North Pole) and -90 degrees latitude (South Pole). [DOC] [TLE] Starry Night Store: The World's Most Realistic Astronomy Products [PAR] Absolute magnitude: The apparent brightnessor magnitudea star would have 
if it ... Antarctic Circle: The line of latitude on Earth's surface that is 23.5 degrees ... 
to 1/60 of a degree, where the sky from the zenith to the horizon is 90 degrees. ... 
Most asteroids orbit between Mars and Jupiter, where they formed; but some... [DOC] [TLE] m1 glossary - The Astronomical Almanac Online - Navy [PAR] Altitude is 90 minus the zenith ... with reference to the apparent orbit of the Sun 
around the Earth. ... appulse: the least apparent distance between one celestial 
object and ... catalog positions of background stars in the same area of the sky, 
after the ...... terminator: the boundary between the illuminated and dark areas of 
a... [DOC] [TLE] Glossary click on a letter A B C D E F G H I J K L M N O P Q R S T U ... [PAR] Altitude ranges from 0 degrees for an object on the horizon to 90 degrees for an 
... Apparent Solar Time - Time kept according to the actual position of the Sun in 
the sky. ... The circle on the celestial sphere which is 90 degrees from the zenith. 
The celestial horizon is approximately the boundary between the Earth and sky. [DOC] [TLE] Astronomy Laboratory Manual - Hartnell College [PAR] Lab Module 4: The Rotation, Revolution, and Precession of the Earth ... changes 
in the observed night sky  changes that have been noticed by ... Ideally you 
should get there ... 1) How many TOTAL degrees did the position of sunset (
sunrise) move between your first ..... horizon represents 0 and zenith is 90 
altitude. [DOC] [TLE] The Position of Uranus in the Night Sky: 2006 to 2019 [PAR] Note that because of the distance of Uranus from the Earth, the angular width of 
... The apparent magnitude of the planet varies little during the period shown in 
the ... star chart is 3".7 (3.7 arcseconds, where 1 arcsecond = 1/3600th of a 
degree). .... up the sky' and 90 when directly above the observer's head (at the 
zenith). [DOC] [TLE] Information - Glossary - Binocular Sky [PAR] Absolute Magnitude: The apparent magnitude that an object would possess it if 
was ... Anomaly: The angle at the Sun between a planet and its perihelion. ... 
Arcminute: One sixtieth of a degree of arc (a circle is divided into 360 ). ... 
Astronomical Unit (

Question: Ideally, this, the apparent boundary between the sky & the Earth, is at 90 degrees from the zenith
Answer: Horizon