Thursday, October 25, 2012

The DC Women's Hiking Group will hike Thurs., Oct. 25th at Aldrich Park in Ridgefield, CT.
Take Farmingville Rd. to New Rd.
Meet in the parking area at 8:30am.

Monday, October 22, 2012

Women's Hiking Group: Oct 23

The DC Women's Hiking Group will hike at Quarry Head in Wilton, CT on Tues., Oct. 23rd.
Take Rt. 35 past the fountain and follow onto Rt. 33 into Wilton.
There will be a State of CT brown sign on the left hand side between mailboxes #760 and #764.
Turn left into the road and follow up the hill.
There will be a sign for parking up ahead.
Meet at 8:30am.

Friday, October 19, 2012

The Orionids Peak Saturday night

Halley's Comet provides October's annual Orionids meteor shower.  Even though the comet will not be visible again until 2061, it is still active.  The Earth crosses its orbit every October.  Like all comets it sheds debris as it gets nearer to the sun.  Some of this debris enters our atmosphere and vaporizes creating "shooting stars" or meteors.  Although it is not as dramatic a shower as the Leonids (November) or the Perseids (August), the Orionids are fairly constant in number.  The best viewing is this weekend between midnight on Saturday and dawn on Sunday.  Meteor showers are named for the portion of the sky that they radiate from.  In this case it is the constellation Orion which will be in the southeast.  However, the meteors are not restricted to that region and may appear anywhere in the sky.   As always, if you want to see the show, you have to find an area where there are little ground lights or obstructions.  You can use Sirius as a guide to the correct area to start looking.  It is the brightest star in the sky.  However, Jupiter will out shine it after midnight.  If viewing the shower in the early dawn hours, Venus will even out shine Jupiter.  Image credit:  Earth & Sky

Wednesday, October 17, 2012

Why the Colors of Fall

Lake Windwing

The days are growing shorter and New England comes alive with color. Why such great color here? The answer lies in our mixed deciduous hardwood forests and our climate. First - Why Color? Leaves are the food factory of a plant. During the summer the leaf's green chlorophylls are working hard to produce food for the plant's survival. They are so abundant, they mask out the other pigments in the leaf. But chlorophylls are very unstable and they must be constantly replaced. As the sunlight diminishes, they are replaced at a slower and slower pace. Eventually the other pigments called caroteniods start to become unmasked. These appear yellow or orange or many hues in-between. The birch or beech trees have an abundance of these.

As time progresses less water and nutrients can enter or exit the leaf. This causes a backlog of chemicals. In some plants, these trapped chemicals, plus light causes anthocyanins to form. These create the reds and purples. The brighter the light during this period, the greater number of anthocyanins are produced and the brighter the color. Some plants like sumacs have so much anthocyanins that they mask the caroteniods completely. While others like the sugar maple slowly produce it so that their leaves first turn yellow, orange then red. But some like the birch can't produce it at all.

Dry sunny days followed by cool dry nights enable the above processes to create the brightest colors. The best variety of color comes from hardwood deciduous forests which contain a wide assortment of trees. New England's climate and forests meet both requirements for world class fall foliage.

Monday, October 15, 2012

The DC  Women's Hiking Group will hike Tues., Oct. 16th and Thurs., Oct. 18th at Weir Farm.
Take Branchville Road and follow National Park signs to Weir Farm.
Meet in parking lot on Nod Hill Rd. across from historic buildings at 8:30am.

Monday, October 8, 2012

The DC Women's Hiking Group will hike Tues., Oct. 9th and Thurs., Oct. 11th at Tarrywile Park in Danbury, CT.
From I-84 take the airport exit.
At end of ramp turn right.
Follow through traffic lights and at stop sign turn onto Southern Blvd. ( It will be a sharp right turn).
Follow small brown signs for Tarrywile Park.
The park will be on the right across from Immaculate H.S.
Meet in parking lot at 8:30am.

Saturday, October 6, 2012

October 2012 Constellation of the Month - Cygnus

Our July 2012 "constellation" of the month, the Summer Triangle, is still high in the sky in October.  Three months later, one would have expected the earth's rotation around the sun to make it appear more to the West.  But, if we're looking at the sky soon after it gets fully dark, we're now looking upwards at about 7:30 PM instead of about 9:30.  So the earth's daily rotation has had 2 fewer hours to move it toward setting in the West.  

The westernmost star in the Triangle is Deneb, in the constellation of Cygnus, the swan.  Cygnus has the shape of a cross and is sometimes called the "Northern Cross".  (There is also a constellation, Crux, popularly known as the "Southern Cross", which is visible to those living in the southern hemisphere of the earth.)  Deneb is at the top of the cross. It is a blue giant star, and it is about 100,000 times brighter than our sun.  

The hazy band of the Milky Way is prominent in Cygnus.  It appears to split in two there, because of the presence of a dark cloud of dust known as the Cygnus Rift, or the Northern Coalsack.  (You guessed it: there is also a Coalsack in the southern sky).   If you follow the Milky Way band to the North and East, you'll see the W-shaped constellation Cassiopeia, which was our constellation of the month for December 2011.  

The foot of the cross is Albireo, which can be seen as a beautiful orange and blue double star in a small telescope, such as those you can look through at a Discovery Center event.  Omicron Cygnii is an orange, blue, and blue triple star. The North American Nebula (shaped like you-know what) and the Veiled Nebular are also in Cygnus.  A powerful source of radio waves (but not seen in visible light), A Cygnii, is a collision of two galaxies, millions of light years away.  Eta Cygnii is an intense X-ray source thought to be caused by a black hole orbiting a blue supergiant star.