THE SOUTHWORTH PLANETARIUM
207-780-4249 www.usm.maine.edu/planet
70 Falmouth Street Portland, Maine 04103
43.6667° N 70.2667° W
Founded January 1970
207-780-4249 www.usm.maine.edu/planet
70 Falmouth Street Portland, Maine 04103
43.6667° N 70.2667° W
Founded January 1970
"Out of bounds"
THE DAILY ASTRONOMER
Wednesday, June 22, 2016
Summer Sky Tour Part I
Six eyes.
Six pointed ears
Three white beards
Three crimson cummerbunds.
Three drooping hats
One joyful smile
One confused frown
One expression of faint interest.
All
focused on the remarkable flower in the remotest part of the Icelandic
wilds that, legend had it, imparted knowledge and wisdom to those in its
proximity. For the last few minutes, the flower stood silent and, as
the tallest of the three visitors believed, it would remain silent
forever. Though presently vibrant under the Sun's influence, it would
soon to decay and dissolve into the rocky soil below. All the while it
wouldn't utter so much as a syllable for, as every sensible soul knows,
flowers don't talk. The shortest visitor, the one who maintained a
hopeful grin, was certain that this remarkable blossom would soon speak,
for he had heard from some of the others that it was, indeed, as it was
believed to be: a sage plant which, like the murmuring willow or the
reeds that repeat ancient secrets once spoken into hollows, conveyed
knowledge to those inclined to receive it. After a few more minutes
of silence, that grin faltered a bit and he met the tallest one's hard
stare with some trepidation, but he didn't give up hope. The one who
was neither the tallest nor the shortest had no idea what to expect, but
decided to remain anyway, if for no other reason than to avoid going
into their hovels. Icelandic summer days were so blissfully long. The
skies were so blue and boundless and the dynamic land so restless with
rumbles and torn by chilled winds that he could have remained there
forever and ever, if only to admire a single flower that was supposed to
start talking any minute now...
Two hands
One knob
One spinning machine
One dome.
Forty people
One microphone
One mind that, for the moment, had to stop day dreaming.
"Ladies
and gentlemen, in a moment we are going to transport ourselves from a
warm June morning to a cooler June evening. We can accomplish this
transition with the aid of that metallic ant poised on the pedestal.
We call that our planetarium projector, although, semantically, that
machine IS the 'planetarium.' Its function it to transform that porous
aluminum dome above our heads into the night sky.
"We
have to admit, of course, that our simulation cannot compete with the
real thing. The actual sky is far more vibrant, energetic, and even
more colorful than this small, but still lovely, replication.
Consider this the map, or the thumbnail sketch that one can use to
navigate around the sky.
"First
matters first. As always, we begin with some distance determination.
The sky is replete with stars, but devoid of road signs. We must figure
out a way to ascertain the directions. Toward this aim, we employ a
technique that navigators used for centuries. We first locate Polaris,
the north star. Despite popular belief to the contrary, it is not the
brightest star, nor is it directly overhead. Instead, it ranks low in
the list of the night sky's fifty brightest stars, and it is 43 degrees
above the northern horizon, because we here in the Southworth
Planetarium are about 43 degrees north of the equator.
Big and Little Dippers
Image by Jerry Lodriguss
Image by Jerry Lodriguss
"Not an easy star to find, but, of course, one can use the Big Dipper to find Polaris. Simply extend a line out from the outer bowl stars about a 'dipper's length' to find Polaris, which, itself, is the end handle star in the Little Dipper.' These patterns are circumpolar, meaning that they will never set, at least not at our latitude. That makes them very handy, for they are always visible and can be used to guide us to the other directions. Our theatre has uni-directional seating, which is why Polaris is to the back of you. South is to your front, the east to the left and the west to the right. Over the course of an evening, the stars appear to migrate across the sky as a consequence of Earth's rotational motion.
"Now that we've established our directions, we proceed at once to the western evening sky to behold the magnificent lion, Leo which, at the moment, is hosting the spectacular giant planet Jupiter. Though we know Jupiter is a behemoth of a world hundreds of times larger and more massive than Earth, it appears star-like. Planets are so far away that we don't see them as discs with the unaided eye. However, they aren't pinpoint light sources so they do not twinkle as stars do.
"Leo the Lion has been perceived as a lion, or a sphinx or another crouching animal for thousands of years. The wonderful thing about constellations is that they maintain their shapes for thousands of years even though the stars comprising them move at more than a hundred miles a second. We, too, sitting here in this theatre, are moving at a comparable speed toward a point in Hercules called the 'apex.' Fantastically, we're moving so quickly because we're in orbit around a supermassive black hole at the galactic nucleus. We're also propelled along by material within the galaxy, most of which we cannot directly observe. That which is unseen moves us along.
"Now that the sky is firmly set, I am going to come out into the audience with you, which is what I prefer to do, anyway. It also gives me the opportunity to use my special microphone. For now, not only am I addressing a captive and entranced audience in the dome, but my voice is also being broadcast in the dense jungles of Equatorial Guinea, the Australian outback, north central Canada, and, now, somewhere in the Westfjords district in Iceland. As a brief backstory, a graduate student in the geosciences does work with us on occasion. An avid traveler, he devised this strange, albeit wondrous, idea of planting special microphones in some of the most isolated parts of the words and, through a technique that I couldn't understand if you explained it to me in small increments, allows my voice to echo at these exotic locales whenever I use this special wireless microphone. So, at the end of this tour, your thunderous applause will shatter the silence of three continents and one northern island nation. Now, I have no idea if anybody is ever able to listen to me or us because he told me he wanted to put these devices in the farthest reaches. Perhaps now that we're broadcasting in Iceland, maybe we're entertaining gnomes! Well, not that they would understand English. ha ha ha!"
Three frowns
"Now, let's continue..."
Part II tomorrow...