Be sure you can explain the following summary points about seasons:
- Seasons in the southern hemisphere are reversed from those in the northern
hemisphere (e.g. summer for us is winter for them).
- The sun is directly overhead at noon on the equator on the first day of spring
(vernal equinox) and on the first day of fall (autumnal equinox).
- The sun is directly overhead at noon on the first day of summer at a point 23.5
degrees north of the equator (called the Tropic of Cancer). On the first day of winter,
the sun is directly overhead at 23.5 degrees south of the equator (called the Tropic of
Capricorn). The first day of summer is also called the summer solstice while the first day
of winter is called the winter solstice. The summer solstice is the "longest
day" of the year while the winter solstice is the "shortest".
- At the poles, seasons are extreme: from the autumnal equinox until the vernal
equinox, you cannot see the sun from the North Pole (and all areas north of the Arctic
Circle). Conversely, the sun never sets from the vernal equinox until the next autumnal
equinox.
- It is hotter in the summer than in the winter NOT because the earth is closer to
the sun (the earth is closest to the sun in January!) but because sunlight hits the ground
more directly in summer (and at a less effective slant in the winter)