Monday, June 23, 2008

First Day of Summer=Longest Day of the Year

While Summer officialy started last night at 6:59pm local time, today was the first full day of the summer season. So what does the first day of summer actually mean?

The answer has to do with the earth's tilting on its axis. As you know, our seasons are determined by the tilting of the earth on its axis, which causes certain parts of the earth to see more sunlight than others, while others see less. During the Summer Solstice, the sun lies directly over the Tropic of Cancer at high noon. This is the northernmost point that the sun reaches throughout the entire year. It is this tilt to the earth that allows the Northern Hemisphere to experience longer days, and therefore, hotter temperatures. The Southern Hemisphere, on the other hand, is now experiencing winter with cold temperatures and long nights. Speaking of long days, in case you have not noticed, today was the longest day of the year. With sunrise at 6:15am this morning and sunset at 8:26pm this evening, we saw 14 hours and 11 minutes worth of daylight. For each successive day that goes by from now until December, each day will get a little bit shorter by a minute or so.