Thursday, June 21, 2007

Summer Solstice

Earth northern hemisphere solstice graphic from WikiCommons
2:06 pm Eastern Daylight Saving Time, 21 June 2007 marks the summer solstice- the longest day of the year {image from WikiCommons}.

This means that the sun appears furthest north in the sky and the time between sunrise and sunset is the greatest providing the most daylight hours for the whole year. For example, sunrise was 6:12 am this morning and sunset will be 9:14 pm. On 21 September, three months from now, sunrise will be 7:28 am and sunset will be 7:41 pm (do your own calculations at the US Naval Observatory)- almost 3 hours more daylight (2 hours, 49 minutes, to be exact).

For more information on this in Ball State's University Libraries and online:

Do keyword searches in CardCat for "vernal," "spring," "autumnal," or "fall" "equinox," or "soltices." You can also type in terms such as "astronomy" or "seasons" for more general information.

You can also find books on this subject and astronomy in general on the shelves under call numbers beginning with Q14 (encyclopedia, dictionaries, glossaries, etc.) or QB63-65 (field guides, star charts, manuals, etc.).

External Links--

"The Egg and the Equinox" and "The Longest Day" from Phil Plait's Bad Astronomy

"Summer Solstice" from Wolfram Research

SkyTonight Almanac from Sky & Telescope

Earth's Seasons: Equinoxes, Solstices, Perihelion, and Aphelion from the US Naval Observatory