Mapping Equinoxes - Understanding Seasonal Change from a Perspective in space

This is both a nice textual and visual explanation of the changes in season.

Quick "Cut & Paste" Highlights:
" ....One of the most frequently misunderstood concepts in science is the reason for Earth’s seasons. As we experience the September equinox today .... we thought we’d offer a space-based view of what’s going on.... The shape of this line between night and day varies with the seasons, which means different lengths of days and differing amounts of warming sunshine...."

"....Of course, it is not the Sun that is moving north or south through the seasons, but a change in the orientation and angles between the Earth and its nearest star. The axis of the Earth is tilted 23.5 degrees relative to the Sun and the ecliptic plane. The axis is tilted away from the Sun at the December solstice and toward the Sun at the June solstice, spreading more and less light on each hemisphere. At the equinoxes, the tilt is at a right angle to the Sun and the light is spread evenly...."

Full article link - click here

Full Credits:

NASA images and animation by Robert Simmon, using data ©2010 EUMETSAT. Caption by Mike Carlowicz.

Instrument:

Meteosat

Related Readings:

1. Stern, D. (2005) From Stargazers to Starships: Seasons of the Year. Accessed September 22, 2011.
2. U.S. Naval Observatory Day and Night Across the Earth. Accessed September 22, 2011.
3. U.S. Naval Oceanographer Earth's Seasons. Accessed September 22, 2011.