Key Things to Know in Earth

• The earth revolves counterclockwise (365 1/4 days) around the sun.
• All celestial objects appear to rise in the east and move west.
• The moon has phases because it revolves around the earth (remember, though, that half is always lit).
• The moon has phases because of the angle at which we view its surface (Remember though: half is always lit).
• Planets APPEAR to go backwards (retrograde) as the earth passes them in space.
• Summer solstice is June 21st: 16 hours daylight - sun rises north of east-vertical ray on 23.5° North, Tropic of Cancer.
• Winter solstice is December 21st: 8 hours daylight - sun rises south of east-vertical ray on 23.5° South, Tropic of Capricorn.
• Equinoxes: Vernal - March 21, Autumnal - September 23, 12 hours daylight, sun rises due east, vertical ray on equator.
• Equator always has 12 hours of day-light.
• The lower the altitude of the sun, the longer the shadow it casts.
• Foucault's pendulum and the coriolis effect prove the earth rotates.
• Earth is closest to the sun in January.
• There are two evidences that the earth rotates: FOUCAULT'S PENDULUM: appears to change its direction of swing.
• Earth is closer to the sun in winter.
• CORIOLIS EFFECT: deflects to the right in the N. hemisphere.
• CORIOLIS EFFECT DEFLECTS THINGS TO THE RIGHT IN THE NORTHERN HEMISPHERE.

Which two factors cause the perpendicular rays of the Sun to move between 23.5° N and 23.5° S?
(1) tilt of Earth’s axis and Earth’s revolution
(2) tilt of Earth’s axis and Earth’s rotation
(3) eccentricity of Earth’s orbit and Earth’s revolution
(4) eccentricity of Earth’s orbit and Earth’s rotation

Answer

1. Which statement best describes the position of the Sun at sunrise and sunset as seen by an observer in New York State on June 21?
(1) The Sun rises north of due east and sets north of due west.
(2) The Sun rises south of due east and sets south of due west.
(3) The Sun rises north of due east and sets south of due west.
(4) The Sun rises south of due east and sets north of due west.