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Suit Yourself™ International Magazine #21: Astronomy On Islesboro

  

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Suit Yourself™ International Magazine #21.2018: Astronomy On Islesboro 

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This week I'm taking a break from our magazine series to remind you about the incredible astronomy viewing we have available to us on Islesboro over the summer months. This is a 2018 update to #21 in our articles series and I hope this information is helpful.

An Astronomy Summer Event 2018 poster for June, July, and August, is available by clicking here:
https://apod.nasa.gov/apod/ap180627.html
or here:
https://www.suityourself.international/2018/180627_AstronomySummer2018Highlights.jpg

All previous articles in the series can be found in our library and in the magazine archives.  Upon request, reprint permission and an addendum of substantiating resources are available for all magazine articles. When requesting reprint permission or addenda, please include the issue date and full issue title. All magazine articles are copyright © Debra Spencer, Suit Yourself ™ International. All rights reserved. ISSN 2474-820X. 

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ASTRONOMY ON ISLESBORO

 

If you live in the city, you're lucky to even see a night sky. The best that can be said for it is that it is 'up'.

 

John Vassos illustration for Ultimo, by Ruth Vassos. 

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Looking up at the night sky on Islesboro, you can see the Milky Way, the spiral galaxy that contains our Solar System, home to our planet that we call Earth. The Milky Way gets it's name because we see the galaxy overhead in the night sky as an enormous, wide band of milky white light, formed from so many millions of stars that our eyes cannot individually distinguish them. 

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 Leçon d'Astronomie.

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Recent estimates of the number of galaxies in the observable universe range from 200 billion to 2 trillion or more, far more stars than all the grains of sand on Earth. Gravity causes galaxies to group into organized clusters, in a vast gaseous space, and these arrange into sheets and filaments surrounded by immense voids. One has to wonder what is being built. 

Our one Milky Way galaxy is estimated to contain 100 to 400 billion stars, and probably at least 100 billion planets. 

Our Solar System is located within our Milky Way disk, approximately 26,000 light years from the Galactic Center, on an inner edge of an outer spiral 'arm' of gas and dust called the Orion Arm.

 

Galaxies.

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Given good weather, you can see at night from our island, with your eyes, and even better with decent binoculars, the wide, broad, dense Milky Way band,  many of the nearest brightest stars, nebulas, the planets Mercury, Venus, Mars, Jupiter, many of the Northern Hemisphere constellations, and the surface of the moon. There are 33 stars within 12.5 light years of Earth.

 

There are 33 stars within 12.5 light years of Earth.

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There is a great deal going on out there, far more than meets the eye. 

This is not a place to lose your luggage.

 

 

Apollo 11 lunar bootprint. 

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To get you started, I'm pointing you in this article to view the Orion constellation and the summertime Perseids Meteor shower. There is, however, so much more to see, and so much more going on out there,  that this seems quite inadequate.  I can only hope you won't think so.  What's going on 'out there' encompasses far more than we are currently capable of imagining,  and we have had to create methods to even begin to comprehend it.  At best, to help you make a beginning, I would be remiss if I did not discuss some of the methods used to aid comprehension, and hopefully make it clearer.  Not that it is possible to make the impossible to imagine clearer, but I'm giving it my best shot. 

 

Harry Whittier Frees photograph:  Three Aeronautical Kittens In Their Balloon. 

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HOW FAR AWAY IS SPACE?

Space is truly vast in outer space. You can't use yard sticks to measure it, and measuring tapes will run out long before it does, so we've had to come up with other ways to specify distances and events interacting inside them.

 It is very difficult to tell how far away something is when you have no way to measure how far away it is.  Graffiti, now long gone, once found at Paddington Station in London, and attributed to The Master of Paddington, said 'Far away is close at hand in images of elsewhere'.  That states this problem. 

 

Audouin Dollfus et son ballon aéronautique. 

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Most of the time, when we want to create a ruler, or measure, or metric, we chose stable things, something stable against which we measure unstable or variable things. Unfortunately, finding stable things to use to measure against is nowhere near as simple as it seems, but sometimes we get lucky.  

For example, our experiments show that the speed of light in a vacuum is stable. We find that, in a vacuum, light travels at 299,792,458 metres per second (approximately 186,282 mi/s). We can use light as a 'constant'; we measure light's speed in water and compare it to the speed of light in a vacuum,  to find out what water does to light traveling through it.  This way, we learn something about both water and light that we didn't know before. 

 

Astronomique 1789.

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As another example, we currently use a decay interval in the caesium atom as our measurement for one 'second' of time, which we consider as 'stable' for all practical purposes. To reduce error, we keep some caesium in a storage container, and reuse it as a 'ruler'.  But because what we now use as the interval for 'one second' is the result of the decay of the particle producing the 'second', it isn't as stable a 'second'  as we would like over time, because over time, the caesium atom we're using is decaying; it's getting smaller. Likewise over time the decay interval we're using to represent our 'second' is faster because less caesium creates less of an interval. Eventually the interval is now a smaller amount than the interval we originally used. A 'second' just isn't what it used to be.  And this will always happen no matter how many times we replace caesium with caesium.

And don't get me started on Calendars. We are always adjusting our calendars. So. To make my point as succinctly as I can,  there are far more than just two different methods of metrics at work here, and by this I don't mean human centimeters versus inches. And I don't mean humans complicating measurement by creating and using dozens of incompatible methods that don't commute. 

Mother Nature has her own ideas; she uses different sets of metrics for different scales, all of which commute, and all of which vary under different configurations. She is, after all, working on a VAST scale of time and space far beyond our comprehensive ability. Mother Nature is in a very different situation that we are.  Humans, on the other hand, coordinate on a relatively tiny time and space scale via relatively fixed intervals, metrics, and measurements. To meet our needs, we use metrics in very different ways and for very different purposes which are rarely in alignment with those of Mother Nature's. However different our scales are from hers, ultimately and invariably, she has the final say, and sooner or later, we are continually having to readjust our scale to perceive what we can of hers, because of something not quite right with ours. As the physicist Richard Feynman once said, "Science is the belief in the ignorance of experts". 

But I digress. Here are some of the ways we measure vastness that we never knew about before we had to measure it.

 

Vue côté est depuis le haut d'un escalier d'un chercheur de comètes à monture anglaise dans sa coupole, avec sa banquette d'observation sur roulettes.

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THE ASTRONOMICAL UNIT AU

One AU is roughly the distance from the Earth to the Sun, but this distance varies because the Earth's orbit around the Sun isn't a circle; it's an ellipse. Originally it was the average of Earth's maximum aphelion orbital distance,  and minimum perihelion orbital distance. This meant that for each individual time we might use this,  we had to do the math and find that individual average, each time. Eventually we discovered that we were really using this metric to represent the entire orbit all the time, and not just pieces of the orbit some of the time, and the results would be more accurate, and make more sense if we just defined one astronomical unit exactly, and used that amount instead.  So now One AU is defined as exactly 149597870700 metres (about 150 million kilometres, or 93 million miles).   I hope you can see how this goes!

 

Vieille gravure de Astronomia et les cartes astronomiques: Éclipses.

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THE LIGHT YEAR

One light year (ly) is the distance our observations show us that light travels in a Julian 365.25 day year going at the rate of 299,792,458 metres per second (approximately 186,282 mi/s).  This often gets rounded to 300,000 kilometers per second, approximately equal to 186,000 miles per second.

 

Louis Théophile Moreux avec son télescope.

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THE PARSEC

Astronomy uses parallax to calibrate distances, and by this I mean trigonometry. We create triangles using measurements taken at different times, in order to find out how far away things are in space. 

The parsec uses parallax. It's defined as being equal to the length of the longer leg of an extremely elongated imaginary right triangle created by the intersection of two measurements in space. It's actually the measurement of the angle inside the apex of the triangle created when and where the two spaced measurements cross. Ancient astronomers would calculate how far away stars were from Earth by taking two measurements of the star six months apart. It was a long wait. 

 

Mesure des angles (gravure allemande).

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The two measurements to the same star, with a six month interval, formed the base of a triangle.  These two measurements intersected at the star, and formed an angle there.  Thus, this all created a triangular in space whose apex crossed at the star.  

One measurement was taken when the Earth was conjunct the sun, and this gave them the distance, or length of one side (leg) of the triangle.  The 2nd measurement was taken six months later, when the Earth was opposite the Sun and had traveled half of its' orbit away from the 1st measurement, and this 2nd measurement gave  the distance, or length, of the 2nd side (leg) of the triangle. The star was located at the apex of the triangle made by the intersection of the two 'legs'; the star was located where these two 'lines' or legs or distances intersected in outer space, and thus they formed an angle there.   Triangle geometry, called Tri-gon-ometry, could then be used to figure out all sorts of very cool relationships.  Trigonometry is incredibly practical for every day life as well as in outerspace, and is fun to learn. Try it, and you'll never tail gate another driver so long as you live. 

This creation of a triangle in space could work even if something was so far away that the angle made at the apex was very small. 
 

 

Christian Huygens (1629-1695) découvre les anneaux de Saturne ainsi que Titan, son plus gros satellite. Sa lunette de 37 m de longueur lui fait découvrir des détails sur Mars la calotte polaire.

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In  2015, the parsec was standardized to the bolometric magnitude scale, which takes into account electromagnetic radiation at all wavelengths. It was given an exact definition in astronomical units, as exactly 648000 divided by Pi in astronomical units, or approximately 3.08567758149137×1016 metres (based on the IAU 2012 exact SI definition of the astronomical unit) and made to correspond to the small-angle definition of the parsec. One parsec is still approximately 3.26 light-years. A kiloparsec (kpc) is a distance of 1000 parsecs (3262 light-years).

For more information on Parallax, see https://en.wikipedia.org/wiki/Parallax
 

 

Gravure 1789, télescope.

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THE CONSTELLATION OF ORION

The three stars of Orion's belt,  Alnitak, Alnilam, and Mintaka, ( Zeta, Epsilon, and Delta Orionis respectively) have been collectively known since antiquity as a trio, by many names, in many cultures. They can be found easily in the night sky by just about anyone, even if you don't know where to look, and I'm about to tell you that, so take advantage of the incredible night sky viewing available here on this island, far from mainland city lights.

 

The constellation of Orion, labels showing belt and stars and bow.

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Alnitak (Zeta Orionis), pronounced ALL-nit-ahk, is at the eastern end of Orion's belt. Alnitak, alternately spelled Al Nitak or Alnitah, comes from the Arabic an-niṭāq, 'the girdle' or 'the belt'; it is actually a star system. Long considered a binary system, in 1998, the bright primary of the system was found to have a close companion. The primary star in the system, Alnitak A, is the brightest class O star in the night sky with a visual magnitude of +2.0, easily visible with the naked eye. It's a hot blue supergiant. 

Alnilam (Epsilon Orionis), pronounced ALL-ni-lham, is the middle star. It's a blue-white supergiant. Alnilam comes from the Arabic Al-nilam, meaning 'string of pearls' and is related to the word 'nilam' meaning 'sapphire'.  It's estimated to be 275,000 to 537,000 times as luminous as our Sun, and around 34 times as massive. It is some 2000 light years away, with a slightly variable magnitude between 1.64 to 1.74, easily visible with the naked eye, and is one of the 58 stars used in celestial navigation. 

Mintaka (Delta Orionis), pronounced MIN-tak-hah, is the westernmost of the three stars of Orion's belt. When Orion is close to the meridian, Mintaka is the right-most of the belt's stars as seen by an observer in the Northern Hemisphere facing south. Mintaka is derived from an Arabic term for belt, 'manṭaqa', and relates to 'area', and 'space'.  Like Alnitak, Mintaka is a multiple star system, whose main component itself is triple. The bright central star of the system, long considered a portent of good fortune, is one of the brightest stars in the sky, easily visible with the naked eye.

During August, in Maine, for those of you with a clear view of the eastern sky early in the morning, you can find Orion the Hunter rather easily. Look for the belt first, then the bright stars of the arms and then the rest of him. You'll also find he's easy to spot via his bow and arrow. There are some good phone apps to help you as well. Try Skyview for Android if it installs on your phone.

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THE PERSEIDS METEOR SHOWER

The Perseids meteor shower is visible from mid-July each year, with the peak in activity between 9 and 14 August, depending on the particular location of the stream. 

 

Gravure en noir et blanc illustrant la Perseids, pluie d'étoiles filantes du 27 novembre 1872.

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Every year, the earth travels through a path of streaming debris particles that has been proliferating for around 1000 years in the wake of comet Swift-Tuttle as it travels on its' 133 year orbit. This debris 'trail' or 'wake' is known as the Perseid 'cloud'.  It's made entirely of variable size and density comet particles, most the size of a grain of sand.  Our Earth, traveling through this wake, produces a lot prettier result than if it were traveling underwater in the dirty Boston harbor. 

As our Earth's orbit passes through the comet's wake, bits of debris randomly strike our atmosphere, hitting our atmosphere at the traffic ticket impact speed of 59 kilometers per second, about 37 miles per hour. The result is a little meteor-atmosphere collision that is nothing short of spectacular. 

The little particle fries on contact with our atmosphere, burning up with a bright glow on impact, and leaving a quick trail, a bright streak, steaming across the sky like a bit of lightening, often in a fraction of a second. Short but sweet. And it's a chance thing; you have to be patient and watch and wait awhile, at the right times, and keep scanning the sky, looking in all the possible places, so you can increase your odds of spotting one of these. It's not something you can succeed at if you're in a hurry, it's best done with friends who are also spotting too, it's a ton of fun, and as the saying goes, it's the journey that's the event. 
 
The streaming debris radiates outwards from the constellation of Perseus; Perseids are primarily visible in the Northern Hemisphere.  More of the particle meteoroids are scooped up by the side of the Earth that is moving forward into the stream. This corresponds to local times between midnight and noon, but these are not really visible by us during the daytime. For all practical purposes, excluding the moon's light, the best viewing time is from just before midnight through the pre-dawn hours, but you need to consider the phase of the Moon, because its' light can interfere with seeing the show. However bright the moon may be, if it's a waxing gibbous moon, then it will set in the sky during the pre-dawn hours, and you'll have the time from then to watch until dawn. Of course, viewing depends on the weather, and if the skies aren't clear, you won't be able to see these. So as the date approaches, even if it's a bit early according to the listed dates, check your weather reports, and if you do have a clear night forecast, try watching for these meteor showers, also called Shooting Stars. There are always surprises.

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VIEWING THE PERSEIDS

While you can look at constellations readily by just popping outside, allowing time for your eyes to adapt, and looking up, to have the best experience viewing the the Perseids requires a bit more effort. 

 

Gravure, La Dioptrique.

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Find a viewing location away from car headlights and house and street lights. Face northeast, and get the widest view of the sky you can, by lying flat on a tarp on the ground, or use a beach chair with a reclining back. Do not wear anything that glows in the dark.  Allow at least 15 minutes outside for your eyes to adjust; some people may seem to adjust sooner, but all of us require switching our eye systems from cones to rods for night vision, and complete adaptation requires at least this long. Wear Deet, protect yourself from mosquitos and ticks, and check yourself, your pets, and your clothes for ticks upon return home.
 

Les Perseids: jeter un oeil!

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MAKE VIEWING A HABIT

Step outside each and every night, even if only for fifteen minutes, and regardless of the weather. Allow your eyes to adjust, look up at the night sky, and see what you can see. Hear what you can hear. Let the sounds of the night settle in, and smell the earth and the air that surrounds you. Be grateful you are not standing on concrete.  Contemplate what you can see of the stars, and the moon if it is up.  By now, it should be obvious that the odds are not in favor of us being alone, however the distances are vast and challenge contact, at least as we imagine it. Nothing else is needed to ponder the wonders of your place in the scheme of things, and to put problems in perspective. Neither belief nor participation is required for awe.

 

Le 17 avril 1912, il photographie, à Mayet, dans la Sarthe, une éclipse du Soleil qui montre que la lune est aplatie aux deux pôles.

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ENJOY!

Astronomie!

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I sign our magazine articles "See Into The Invisible". Thanks for reading.

Best Wishes, 
Debra Spencer

All Content is © Debra Spencer, Suit Yourself™ International. Technical Library FAQ Index ISSN 2474-820X. All Rights Reserved. Please do not reproduce in part or in whole without express written consent. Thank you.
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All Content is ©2019 Debra Spencer, Appanage™at www.suityourself.international Suit Yourself ™ International, 120 Pendleton Point, Islesboro Island, Maine, 04848, USA 44n31 68w91 Technical Library FAQ Index ISSN 2474-820X. All Rights Reserved. Please do not reproduce in part or in whole without express written consent. Thank you.

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All Content is ©2019 Debra Spencer, Appanage™at www.suityourself.international Suit Yourself ™ International, 120 Pendleton Point, Islesboro Island, Maine, 04848, USA 44n31 68w91 Technical Library FAQ Index ISSN 2474-820X. All Rights Reserved. Please do not reproduce in part or in whole without express written consent. Thank you.
Success consists of going from failure to failure without loss of enthusiasm. ~ Winston Churchill