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 18, 2012
Tuesday, December 11, 2012
Saturday, December 8, 2012
Triangulum
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.
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.
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
Tuesday, November 13, 2012
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
Thursday, October 25, 2012
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.
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
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.
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
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.
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)
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