Category Archives: Science-Nature

Backyard Astronomy at the Haston Library

Posted on by

Tonight I joined about twenty other North Brookfield residents for a presentation titled Backyard Astronomy: Scanning July Skies Using the New Library Telescope by John Root and Jim Zebrowski, both of the Aldrich Astronomical Society.  Founded in 1932 and operating out of Anna Maria College in Paxton, the organization has a presence in 19 states.  Mr Root is the Library Telescope Program Coordinator, and Mr Zebrowski is the President of the Society.  Thanks to a donation from Country Bank in Ware, the Haston Free Public Library in North Brookfield now owns a new telescope which patrons can borrow as if it were a book.

The Library Program began eight and a half years ago, in New Hampshire, and quickly became so successful that it was featured in an October 2014 article in Sky and Telescope magazine.  The first two libraries to participate in this program were the Paxton Library and the Winchendon Library.  Out of the original fourteen Massachusetts libraries which expressed interest in the program, half managed to obtain funding within the first year.  That number has grown: today, there are 126 Massachusetts libraries with telescopes, and the program is expanding into neighboring Connecticut and Rhode Island.

The library’s new telescope is an Orion reflector telescope, with some specific modifications to make it easier for novices to use.  For example, it has a Zoom Eyepiece enabling a range of magnifications, as well as a Rack-and-Pinion Focuser with EZ Finder (meaning you can “put the red dot on what you want to see”).  For the unsuspecting user, the images one sees will be upside down and backward.  Another feature of this modded telescope is power provided by 2 AA batteries, instead of one button battery.

When a patron borrows the telescope, he or she will also take home an accessory pouch, with two important publications: a guide to the constellations, and an instruction manual.  In accordance with principles of good UX design, controlling buttons — knobs, covers, and switches — are marked by a green dot, but patrons need only adjust magnification and focus.  Patrons are advised not to touch the optical surfaces, ever, and to familiarize themselves with the telescope operations during the day, before they attempt to view anything in the night sky.  Most importantly, NEVER point the telescope at the sun, as that will cause permanent blindness.  Parents: please supervise your children’s use of this sophisticated optical instrument.

The presentation touched briefly on what’s important in telescope specifications: although lay people assume magnification is most important, aperture, the diameter of the light-gathering lens or mirror, is far more critical.  Even with 50x magnification, one can see Jupiter’s moons and Saturn’s rings.  Patrons interested in purchasing their own telescopes would do well to consult with a local astronomy club, like the Aldrich group.  In addition, if library patrons find themselves becoming hooked on this new hobby, local clubs are a helpful resource in matters such as telescope etiquette (yes, there is such a thing).

So, what is there to see?  Stars, of course.  The night sky has fascinated humans for millennia, and cultures as diverse as the Babylonians and Native American Micmacs have named the constellations, or star groups.  Early in the 20th century, the International Astronomical Union (IAU) ratified and recognized 88 modern constellations.  This may seem overwhelming, but spotting only a few of these star groups will enable you to see even more.  Here’s how it works: for those of us in the northern hemisphere, look for the Big Dipper (in the constellation Ursa Major), with its seven bright stars.  Follow the lip of the dipper to Polaris, the North Star, in the Little Dipper.  Above that will be Cassiopeia, in the shape of an “M” or “W” or “3” or “E” (whatever).

Another group of summer stars that are easily identifiable are those of the Summer Triangle.  At the apex, Vega is the brightest.  To the lower left is Deneb, and to the lower right is Altair. (Vega is in the constellation Lyra, Deneb is in Cygnus, and Altair is in Aquila.)  Being able to spot the Summer Triangle will lead you to the Milky Way, which passes between Vega and Altair.

The cool thing about looking at the night sky through a telescope is that you can see so much more than with the naked eye.  For example, many stars we see are double stars, or even double-double stars.  Look for the star Mizar with its faint double Alcor in the Big Dipper.  Look for other interesting sky phenomena such as the Double Cluster in Perseus (just below Cassiopeia) or the globular cluster M13.  And yes, look for Jupiter’s Red Spot or its moons and the rings of Saturn.  You may not want to look at the full moon, as you’ll probably be disappointed.

Another phenomenon you might see if you’re lucky is the Aurora Borealis, even in our area in the summer.  The best way to predict when the aurora might be visible is to keep track of the sun’s geomagnetic activity.  To do this, you can look at a scale called the Kp index, a scale of 0 to 9, that shows the geomagnetic activity in the atmosphere, 1 being calm and 9 being high activity. For our latitude, the Kp index has to be greater than 6 for us to have a good chance of seeing the Northern Lights.  Websites such as http://www.spaceweather.com/ can be helpful in this regard.

This month, July, also marks the two-year anniversary of the successful flyby of dwarf planet Pluto by NASA’s New Horizons spacecraft.  According to the NASA website, “Clyde Tombaugh was tasked to look for Planet X, theorized to exist beyond the orbit of Neptune. He discovered a faint point of light that we now see as a complex and fascinating world.” (The naming of Pluto is also an interesting story.)  Mr Zebrowski mentioned that the re-classification of Pluto came about when astronomers explored other planetary systems in our galaxy and thus began to have a better understanding of the objects in our own solar system and how they might have been formed.  As of now, we have eight planets (the four terrestrial planets, the two gas giants, and the two cold rocky ones), the asteroid belt between Mars and Jupiter, and the Kuiper Belt beyond Neptune, composed of KBOs (Kuiper Belt Objects) such as comets and dwarf planets.

No presentation on backyard astronomy in July 2017 would be complete without a reference to a daytime celestial event happening a month from now, on August 21st: the total solar eclipse.  It will be visible throughout the continental United States, beginning in Oregon at around 10:15 am and ending in South Carolina at around 2:36 pm.  Here in New England, we will see a partial, about 63.5% cover.  Although the moon passes between the earth and the sun every month, total solar eclipses don’t occur that often.  They are not rare, but few people see them, because so much of our planet is covered by oceans, for one thing, and weather conditions have to be favorable, for another.  Another reason is that the orbits of three bodies, earth, moon, and sun, have to align just so, and due to the moon’s orbit being tilted about 5 degrees out of synch with the earth’s orbit, most often the moon is too high or too low in the sky to pass in front of the sun.  If you are interested in viewing the solar eclipse, DO NOT look at the sun directly.  You can purchase special glasses which will protect your eyes, but you can can also use pinhole projection to view the eclipse safely.

The two presenters also set up a display table in the meeting area with additional information about their organization and about astronomy in general.  After the presentation, they held a drawing for door prizes, but onIy the children were allowed to participate.  I was much more interested in the two meteorite samples they brought, one of which was much heavier than I expected.  They explained that there are three main types of meteorites: stony, iron, and stony-iron.  The iron ones are the heavy ones; the stony ones with small, colorful, grain-like inclusions are the chondrites; the stony-iron ones are quite rare.

History and Nature in Southbridge

Posted on by

As a member of the Opacum Land Trust, I was invited to a guided walk this morning at the Claire Birtz Sanctuary in Southbridge, a 116 acre property on the west side of Route 169 and very near the Connecticut border.  Opacum Board member Alan Smith led a small group of us on a two hour hike: we started off on the Blue Trail, picked up the Yellow Trail, bushwhacked for a bit to the property line, and then returned to the parking area via the Blue Trail again.

The walk description promised us “a historical journey through the past use of this interesting property” as well as a discussion of natural features such as vernal pools.  A geologist and archaeologist, Al impressed us with his wealth of knowledge.  I wanted to soak in the atmosphere and enjoy myself, so I only scribbled down a few notes.  The following are more or less random observations, but they are what I found striking and worth recording, organized into four groups.

Geology

New England’s current landscape is glacially formed.  The retreat of the ice sheets during the most recent glacial period, the Wisconsin, occurred 12,000-15,000 years ago.  Landforms like drumlins and kettle ponds, common in New England, were formed when the glaciers receded.

Prior to the glaciation events, back in the distant past — in fact, 365-425 million years ago — this area experienced the Acadian orogeny, which was the third of the four orogenies that created the Appalachian Mountain chain.

These mountain-building events can be inferred from tilted planes of rock which we see on this property and at numerous nearby sites; these are evidence of thrust faulting.

Rocks in the Southbridge area are often granite (igneous) or granitic gneiss (metamorphic).

A glacial erratic is composed of rock that differs from the surrounding substrate, whereas a glacial boulder is a rock like all the other rocks around it, only bigger.

Scientists estimate that the Earth is about 4.5 billion years old, but the oldest rocks in Massachusetts are only about a billion years old (due to extensive mountain building events which recycle and reform the Earth’s crust); these rocks from the Grenville orogeny, dated to about 1.2 billion years ago, can be found in the Berkshire highlands.

Archaeology and Human Habitation

Native Americans used waterways as roads; rivers and streams were their transportation corridors.  The pictures we have in our heads of Algonquian tribes paddling around in their birchbark canoes have a basis in fact.

Colonists who built stone walls used the materials they found to hand: blocky, rectangular stones from the mountain-building episodes and rounded stones sculpted into that shape by glacial action and running water.  You can see both types in this section of wall:

The shallow depression we saw near the property boundary line could be a cellar hole, but it could also have been a Native American sweat lodge.

In the mid-eighteenth century, when Native Americans were losing their land to settlers, they often lived “under the radar” so to speak; in the colonial era, they might have worked at the Sturbridge Lead Mine, but they also continued observing traditional practices to the extent that they could.  This stone structure could have served a religious or ceremonial purpose:

A common system for classifying soils defines distinct strata by their color and composition, as well as inclusions: A-dark, B-yellow, C-light yellow, then bedrock underneath.

Flora

Spicebush (Lindera benzoin) grows in rich soil; its tiny yellow flowers appear in early spring and red drupes (berries) in the fall.

Witch Hazel (Hamamelis virginiana) is used medicinally.

Ferns (Cinnamon, Interrupted, Christmas, and more!) are common in the understory.

Mountain Laurel (Kalmia latifolia) blooms in early summer.

Groundnuts (Apios americana) are edible and, although not cultivated, were used as a food source by the early colonists.

Maple Leaf Viburnum (Viburnum acerifolium) has leaves which look like maple leaves, but this plant is a vine, not a tree.

Plane trees (genus Platanus) are native to the northern hemisphere; their leaves may look like maple leaves, but this is a different genus; there are fossil records of plane trees from as far back as 115 million years ago.

The Cattail Swamp, adjacent to Morse Pond, is a prominent feature of the sanctuary.  The cattail (Typha latifolia) is a versatile plant for human use: the rhizomes can be ground into flour; the stems can be cooked; the leaves are edible, as are flowerheads; the fluff can be used to line moccasins or for bedding.

Fauna

Intermittent streams are home to salamanders.

Certified vernal pools do not have fish in them; instead they harbor species like frogs and fairy shrimp.  It’s hard to see in this photo, but this is a vernal pool:

Garter snakes are harmless and should be left alone:

At the end of the walk, Al offered to lead the group to the remains of a nineteenth century mill dam nearby, but I had another engagement on my calendar and had to hurry on home.