Eyes to the Sky: Colored autumn leaves and falling stars
The hills are becoming more and more colorful as sunlight is becoming scarcer. Leaves exhibit a beautiful way of dying each autumn -- after having prepared their twigs with buds that sleep through the winter, ready to flower and leaf out in spring.
The production of the green agent in leaves, chlorophyll, has slowed in many deciduous plants and ceased in others as a result of the diminishing time and intensity of sunlight.
It is intriguing to discover that when chlorophyll disappears from leaves another component is revealed. Carotenoid, which may persist and increase, makes for the yellow, orange and red leaf colors. Still other agents are active in various species, most notably flavonoides, that produce, for instance, the vermillion of sugar maple trees, as well as purple and blue hues.
Longer nights mean longer periods of cool temperatures. Weather phenomena that are independent of day length are secondary in determining the timing of leaf change.
Warm, sunny days and cool nights are reported to effect the best color. Hot days speed the process and may lessen color intensity. Drought delays color change and early frosts may cause leaf drop. The Forest Service's Fall Color Hotline (1.800.354.4595), which offers reports from the entire United States, is suspended at the time of this writing due to the government shutdown.
Meteors, also known as falling stars, will be falling with the leaves in the wee hours as the week and month progress. The Southern Taurid meteor shower peaks next Thursday, the 10th. Five meteors per hour are predicted; however, shooting stars associated with the Orionid shower may also appear. Look to the south, below and to the right of brilliant Jupiter, before dawn until about 5:30 a.m.
To contact Judy Isacoff go to: www.naturesturn.org
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