Tuesday, December 18, 2012

The DC Women's Hiking Group will hike Tues., Dec. 18th and Thurs., Dec. 20th at Aldrich Park in Ridgefield.
Take Farmingville Rd. to New Rd.
The park is off of New Rd.
Meet in parking area at 8:30am.

Tuesday, December 11, 2012

The DC Women's Hiking Group will hike Tues., Dec. 11th and Thurs., Dec. 13th at Bennetts Pond in Ridgefield.
Take Rt. 7 to Bennetts Farm Rd.
Follow Bennetts Farm Rd. to parking lot on right hand side of road.
Meet at 8:30am.

Saturday, December 8, 2012


December 2012 Constellation of the Month:  Triangulum

To the west of the great square of Pegasus, which we described last month, near the wishbone-shaped Perseus (January, 2012) is Triangulum.  It is a compact triangle with somewhat faint stars, so it will be a little challenging to find.  Some consider it an especially attractive constellation.

The big item of interest in Triangulum is the Triangulum Galaxy, M33.  It is the 3rd largest galaxy in our little Local Group of galaxies – after the Andromeda Galaxy (see Nov. 2012), and our own Milky Way.  When seen through binoculars or a small telescope, like the Discovery Center's, it is about the size of the full moon.  

Which brings us to the question we posed last month:  How many full moons, side-by-side, would it take to stretch across the sky in a line (arc) from the eastern horizon to the western horizon?  The answer is about 360 – which is a lot more than most people guess.  That, coincidentally, is the number of degrees in a circle.  Since the arc we're talking about is a half-circle, the Moon is about ½ degrees in diameter, as it appears to us in the sky.  This, in an extremely unlikely coincidence, is the same size as the disk of the Sun.  That is why, in a full eclipse of the sun, the Moon will almost exactly cover the Sun. 

You can prove this half-degree figure for yourself – and maybe win a bet or two, at sunset (or moonset).  When the bottom of the circle of the sun touches the horizon in the West, how long will it take for the Sun to completely set?  The answer is 2 minutes, which is a lot quicker than most people would guess.

Here's how you can use that information to calculate with width of the Sun or Moon in degrees of a circle.  The Sun or Moon traverse across the half-circle (180 degrees) of the sky in 12 hours, which is 720 minutes.  2 minutes is 1/360th of 720 minutes.  1/360th of 180 degrees (the arc of the sky) is ½ degree.

Monday, December 3, 2012

The DC Women's Hiking Group will hike Tuesday, Dec. 4th and Thursday, Dec. 6th at Bear Mountain Reservation in Danbury, CT.
Take exit 5 off of I-84. Follow Rt. 37 North past all the shopping centers. Go past the
commercialized district and eventually past the federal prison into the more
rural part of northern Danbury. About 0.2 mile past the prison entrance, on
the right, is Bear Mountain Road which is 2.8 miles from I-84. Turn right
onto Bear Mountain Road and follow it for 0.5 mile. Turn right into the
entrance of Bear Mountain Reservation.
Meet in the parking area at 8:30am.

Tuesday, November 20, 2012

The DC Women's Hiking Group will hike Tues., Nov. 27th and Thurs., Nov. 29th at Topstone Park in Redding, CT.
Take Rt. 7 to Topstone Road.
Follow over railroad tracks staying on Topstone Rd.
Keep going just past where it turns to a dirt road.
Parking area will be on right side of road.
Meet at 8:30am.

Monday, November 19, 2012

The DC Women's Hiking Group will hike Tuesday, Nov. 20th on the Rail Trail and into the Florida Refuge area.
Park and meet at the end of Halpin Lane in Ridgefield at 8:30am.
Happy Thanksgiving!

Tuesday, November 13, 2012

The DC Women's Hiking Group will hike Tues., Nov. 13th and Thurs., Nov. 15th at Pierrepont State Park in Ridgefield, CT.
Meet in parking area off Barlow Mountain Rd. at 8:30am.

Monday, November 12, 2012

November 2012 Constellations of the Month -- Pegasus and Andromeda

November 2012 Constellations of the Month: Pegasus and Andromeda

High in the sky and a little to the West are our November 2012 constellations of the month, Pegasus and Andromeda.  They are south and east of last month's constellation, Cygnus, and south and west of our Dec. 2011 constellation, Cassiopeia, "the W".

They look like a big square, with some appendages.  This is called the Great Square of Pegasus, even though the northeast star in the square belongs to Andromeda (which is why we needed to have 2 constellations this month).  Can you guess how many side-by-side full moons it would take to stretch across one side of the square?  

At the end of one of the appendages is the globular star cluster M15, which has about 100,000 stars.  Globular clusters, unlike other stars and clusters we see in our Milky Way galaxy, are not located in the disk of the galaxy.  They are found "above" and "below" (there is no direction which is "up" or "down" in space) the central part of the disk.  They formed before the rest of the galaxy took shape. 

Andromeda's stars are relatively faint, and they don't form a recognizable shape.  But the constellation has one major attraction – M 31, the Andromeda Galaxy.   It is a huge spiral galaxy which looks much like our own Milky Way.  It is bigger than the Milky Way and contains about a trillion stars, which is at least twice as many as the Milky Way.  It is bright enough to be seen with the naked eye.   It appears so bright, because it is so close -- only 2.5 million light years (16 trillion miles) away.  With the naked eye, it looks about as wide as 3 full moons.

... which brings us to the earlier question of how many full moons would stretch across a side of the Great Square – Answer: about 30.  That's a lot more than most of us would guess.  Here's a question which will be answered next month: How many moons, side-by-side, would it take to stretch across the sky in a line (arc) from the eastern horizon to the western horizon?

Wednesday, November 7, 2012

The DC Women's Hiking Group will hike Thursday, Nov. 8th at Pierrepont State Park in Ridgefield, CT.
Meet in parking area off Barlow Mountain Rd. at 8:30am.

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.  

Sunday, September 30, 2012

Why do Geese Fly in a V

The fall migration of birds is well underway.  In the meadow outside my home in NH, there are flocks of white-throats sparrows and juncos feeding on seeds and insects.  Also there is the lovely sound of geese overhead flying in formation towards the beaver pond down the hill.  Have you ever wondered why geese fly in a V-formation?  Migration uses up lots of precise energy.  By flying in a V, the flock is conserving energy.  How?  Each goose flies slightly above the one in front of it.  This cuts down on wind resistance because the flapping of the bird in front creates an uplifting draft of air making it easier for the bird behind it to fly.  The energy saved in flight can be as much as 50%.  Therefore the lead bird is working the hardest while the rest of the birds can glide more and use less energy.  When the lead bird tires, it will fall back in the formation to an easier flying position and another bird will take over the lead.  This way the flock shares the hardest work.  Also, this type of formation allows for the birds to keep track of each other.  This assists in the communication within the flock and its coordination.  Who are in the flocks? Usually they are individual or multiple family groups.  Research shows that geese families will stay together during migration and in their winter feeding grounds.  It isn't until the springtime when they return to their breeding grounds, that the yearlings will venture off on their own. Fun Fact:  A group of geese on the ground is a gaggle, but a flock in  the air is a skein.  Photo:  About.com - San Francisco

Friday, September 28, 2012

The DC Women's Hiking Group will hike Tues., Oct. 2nd and Thurs., Oct. 4th at Lake Windwing in  Ridgefield, across from Ridgebury Elementary School, off of South Shore Drive.
Meet at 8:30am in the parking area.

Monday, September 24, 2012

The DC Women's Hiking Group will hike Tues., Sept. 25th and Thurs., Sept. 27th at Saugatuck Falls Natural Area in Redding, CT.
Saugatuck Falls Natural Area entrance is located between mail box # 65 and 73 on Diamond Hill Road, Redding. Follow straight in until you see the large sign (entrance marker) on your left.
Meet at 8:30am.

Saturday, September 22, 2012

Autumnal Equinox

Today is the Autumnal (fall) Equinox.  Although most people hardly even notice it, the natural world is now speeding up the process of winter preparation.  The young of spring are now mature and for some learning their last lessons in survival.  The sun’s quickening demise is triggering the internal clocks for others to start heading southward.    Those that must stay are packing on the pounds in preparation for the lean months ahead.  Plants are reacting by sowing their seeds and green plants are decreasing chlorophyll production.  This will eventually lead to exposing the other colors that had been hidden by the green into the brilliant colors of fall.  For the farmers who still live by the seasons, it means the last harvest of the year.  
      Thanks to the earth’s 23.5° tilt, equinoxes occur twice a year – in March and September.  It is when day and night are nearly exactly the same length.  The word equinox is derived from Latin, meaning “equal night”.  However, to the casual observer, this doesn’t seem correct.   The day time seems longer than the 12 hours. There are two reasons for this.  First, sunrise and sunset times are calculated by the outer edge of the sun’s disk not the center.  So the disk is still in the sky after sunset occurs.  Second, the Earth’s atmosphere refracts light.  This gives the illusion that the sun is in the sky longer than it really is.  The Autumnal Equinox is the herald of winter.  If this depresses you, head to the southern hemisphere where today it is the Spring Equinox.  (Picture credit: Kimberly Achelis Hoggan)