AST101H1 Lecture Notes - Lecture 6: Lunar Phase, Ecliptic, Northern Hemisphere

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST101H1
• Professor: Eryan Apsnler, Michael Reid

Document Summary

The seasons (cont. ) (continued from lecture 5 notes) Earth"s axis constantly points to polaris, regardless of where earth is in its orbit. Solstice represents a day where an extreme in earth"s axis" distance to the sun is achieved. Summer solstice: northern hemisphere is tilted maximally towards the sun , resulting in increased warmth there. Also contributing to the warmth of an exposed hemisphere is the duration of daylight hours; warmth is not only greater, but also lasts longer. Winter solstice: northern hemisphere is tilted maximally away from the sun, resulting in cooler temperatures and shorter daylight hours there. Equinox represents a day where earth"s axis achieves a neutral position relative to the sun in its orbits. Same side of the moon faces the earth each time, every time. Waxing = more illumination; initial half of the lunar cycle. Waning = less illumination; final half of lunar cycle.