The vernal equinox celebrated

A woman crouches amongst the daffodils in London's St James' Park to take a photograph, as the capital enjoyed spring sunshine on March 20, 2009. (ADRIAN DENNIS/AFP/Getty Images)

People attend the spring equinox in front of the Kukulkan Pyramid (or "El Castillo") in Chichen Itza, Mexico, Saturday, March 21, 2009. This Mayan pyramid was built so that the shadows of a corner of the pyramid would fall on a stairway and create the image of an illuminated serpent (visible on the left side). (AP Photo/Israel Leal)

Iraqi Kurds carry torches up a rocky hill as they celebrate Nowruz in the Kurdish town of Akra, 500km north of Baghdad on March 20, 2009. Nowruz marks the first day of spring and the beginning of the year in Iranian calendar. It is celebrated on the day of the astronomical vernal equinox, which usually occurs on March 21. (SAFIN HAMED/AFP/Getty Images)

An Afghan girl plays as others gather to celebrate the Afghan New Year in Kabul March 21, 2009. Afghanistan uses the Persian calendar which runs from the vernal equinox. The calendar takes as its start date the time when the Prophet Mohammad moved from Mecca to Medina in 621 AD. The current Persian year is 1388. (REUTERS/Omar Sobhani)

Strollers walk through a sea of crocusses in the park of the castle in Husum, northern Germany, as temperatures reached nine degrees Celsius (48.2 Fahrenheit) on Tuesday, March 17, 2009. According to a legend, monks in the 15th century planted the first crocusses here, and today some 4.5 million of them blossom here. (AP Photo/Heribert Proepper)

Several dozen more photographs at Boston.com's The Big Picture.