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.