2.1, 4.1, 4.2 Notes

Slide 1

Terms to refresh your memory
AM: anti-meridian PM: Post-meridian solar noon: the highest point the sun is in the sky longitude: angle measured from prime meridian -east to west latitude: angle from equator -north to south circumpolar: objects near the north pole that never seem to set

Slide 2

Constellation- one of 88 sectors of the sky asterism - star pattern within a constellation ecliptic - path sun takes around celestial sphere declination - angular distance of a point North or South of the celestial equator right ascension - the distance of a point measured by the East of the First Point of Aries, measured along the celestial equator and expressed in hours, minutes, and seconds. celestial equator - the projection into space of the earth's equator, equidistant from the celestial poles equator -  great circle constituting of the parallel 0 degrees, dividing the earth into hemispheres First Point of Aries: vernal equinox

Slide 3

  *the sky rotates opposite of the celestial poles *rises on east, sets in west -The star Polaris is also known as the fastener of the sky *earth rotates counterclockwise *planet means "wanderer" in Greek *halfway b/w the poles, 90 degrees, is the celestial equator
Things to Note

Slide 4

Declination and Right Ascension
Declination is measured just the same as latitude (from the equator)       North: positive values                         South: negative values   Right Ascension is similar to longitude, but counted from the "vernal equinox" , where the ecliptic crosses the celestial equator. 360 degrees = 24 hours 15 degrees = 1 hour

Slide 5

Seasons
*become more pronounced the further N or S one travels from the equator  Seasons are not caused by the distance earth is from the sun, but rather by the degree of the earth's axis tilt (23.5 degrees.)   The vernal and autumnal equinoxes deliver equal amounts of sunlight across the globe The North leans in toward the sun during the summer solstice, and away during the winter solstice The South leans in toward the sun during the winter solstice, and away during the summer solstice The angle determines the intensity/where the earth receives the most sunlight (heating distribution)   During the summer, The north receives the most hours of sunlight During the equinoxes, the both hemispheres receive equal hourly amounts of sunlight During the winter, the South receives the most hours of sunlight

Slide 6