Once in a Lifetime Event (literally!)

In astronomical terms, “once in a lifetime” conjures images of a rare celestial event, such as a total eclipse of the sun or moon. While they are indeed few and far between, the phrase is applicable in the sense that the opportunity for the average person to be able to actually see our star blocked out by the moon passing directly in front of it is indeed “once in a lifetime”: the path of totality, or the moon’s ultra-narrow shadow, only falls close to where a person lives at one point in his or her life. Only affluent people, with money AND time on their hands, can travel halfway around the world to observe one, to get inside that narrow “cone” of totality.

But when it comes to a transit of an inner planet such as Mercury or Venus (think of them as mini-eclipses), it really is a once-in-a-lifetime experience…especially in the case of the latter. The relatively recent transit of Venus crossing over the face of our sun happened in June 2012. And Yours Truly was able to see it, and even captured the image!

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Venus, of course, passes between Earth and the Sun quite often, as does Mercury and our own moon. But since planets have different orbital planes, most of the time they seem to go just above or just below our daytime star.

Venus transits only occur twice a century. Nobody will be alive to see the next one: December 11, 2117…but if you missed the above-mentioned one, plenty of folks took lots of pictures, including Moi:

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I happened to be living in Southeastern Tennessee in June 2012. The transit began for us late in the afternoon, so I was able to observe the first hour or so before the sun went behind some nearby trees. Here’s another, closer image:

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There were two reasons I used a white cardboard surface to see the image: not only for the sake of a simple, casual shot, but also to avoid going blind from attempting to observe the transit directly through the telescope (never, NEVER look a the Sun through a telescope, or you will wear that image on your retinas for the rest of your life…and be blind).

The coolest thing about this event was that I knew precisely when it would begin. I was watching the projected image of the Sun on the back of a spiral notebook…waited…waited…and then a “bite” occurred, right on schedule, on one side of the Sun’s disk! I was transfixed. It slowly emerged as a distinct, well-defined ball. Lots of folks took far better pictures of this transit, but I think my uber-casual shot lends a unique perspective!

Here is a link to a few “serious” shots, taken by amateur photographers:

When I say “amateur” shots, by that I mean these intrepid folks make no more of a living than I do with their photography…but they have far more sophisticated (and expensive) gear than I possess.

Now take a look at the next shot: Venus again, but taken three weeks after the transit date…when the planet had moved enough in its orbit to become the morning star once again:

Venus, aka the morning star, 5/7/12

Venus, aka the evening star, 5/7/12

To the extent you’re able, try to enjoy rare celestial events such as a transit. The next one of Mercury (and its last for a few decades) will occur on May 9, 2016.

Maybe, just maybe, the weather will cooperate!

Clear Skies,

Jesse

The Beautiful Corner Of Tennessee!

If there’s a prettier spot in the Volunteer State, I’d like to know where it is: Chattanooga, Tennessee, and its immediate vicinity to the East.
From Lookout Mountain (overlooking the heart of downtown Chattanooga) to the “foothills” of the Appalachian Chain, this area can be sheer sensory overload, all year round:

Chattanooga, from Lookout Mountain

Chattanooga, from Lookout Mountain.

The above photo was taken from Point Park, atop Lookout Mountain, an easy day trip from anywhere in the Chattanooga or Cleveland, TN vicinity. My wife and I spent a gorgeous Saturday at the summit recently. I won’t go into a historical diatribe, but troops were indeed garrisoned here, during the civil war…it was a bit cold during those winter months, sure.

My Better Half!

My Better Half!

It would be a challenge to take a bad photograph, given this vista!

Long-dormant, but no less imposing, artillery, keeping watch over Chattanooga.

Long-dormant, but no less imposing, artillery, keeping watch over Chattanooga.

There’s a virtual 270-degree panorama, as illustrated below:

Looking West...

Looking West…

...and Northeast!

…and Northeast!

If we can tear ourselves away, another imposing observational site resides a mere thirty minutes or so due East…Chilhowee Mountain! While not part of its much more famous mountain brethren in the Smoky Mountain National Park, it is indeed part of the same mountain chain: the Appalachians. Chilhowee has three observation decks, each with a unique angle on the breathtaking Ocowee Lake, imbedded in the valley. This shot was taken from the “middle” observation vantage point, gazing West:

Ocowee Lake, from Chilhowee Mountain.

Ocowee Lake, from Chilhowee Mountain.

A shift to the Northeast yields another gorgeous vista:

Looking NE, June.

Looking NE, June.

And the same sight, late October:

October...yes, it was getting chilly!

October…yes, it was getting chilly!

Looking Southwest, from an altitude of 2200 feet.

Looking Southwest, from an altitude of 2200 feet.

Chilhowee is also honeycombed with hiking trails, from “beginner” treks to more challenging ones…one of the latter, approximately 2.5 miles in and out, yielded a nice place to kick off the shoes and socks, and have lunch: Benton Falls!

Not a bad place to stop, catch your breath, and just Take It All In.

Not a bad place to stop, catch your breath, and just Take It All In.

And while I can’t recommend the next scenic walk for the average person, on a pretty day it does indeed have its charm:

Note the spacious shoulders, should the need for a hasty dismount arise.

Note the spacious shoulders, should the need for a hasty dismount arise.

But one more excursion to the top of Chilhowee: I spent an afternoon up here, at 2200 feet, writing, and taking the preternatural quiet in. You just have to experience this serenity, first-hand, to appreciate just how beautiful Nature can be.

The Summit, Chilhowee, an hour before dusk, late October.

The Summit, Chilhowee, an hour before dusk, late October.

In my opinion, the Chattanooga-Cleveland area is as visually striking as Smoky Mountain National Park, without all the tourists…at least until this “secret” gets out. All of this is just off Interstate 24 (Chattanooga), and I-75 (Cleveland, just NE of the former).

If you reside anywhere close to this region, it’s definitely worth checking out!

Types of Telescopes #1: The Venerable Refractor

Last time I gave a brief introduction to the two prevalent types of telescopes, refractors and reflectors. These warrant further scrutiny, so we’ll focus on the older of the two designs:the traditional refractor telescope.

Author's 150mm, f/8 refractor telescope.

Author’s 150mm, f/8 refractor telescope.

A refractor, as the name implies, bends or refracts incoming light. It utilizes at least two glass elements, or lenses, mounted at the front of the scope. This instrument is the one most people think of when the word “telescope” pops out in conversation. Until very recently, it is the type seen in movies and TV shows, as a prop in the background, against the window of some executive with a penthouse view.

Why two lens elements? When light is refracted, its constituent color elements are bent as they pass through a glass lens, and come into focus at different places on the focal plane. With the original design, in the early seventeenth century, a single glass element caused serious chromatic aberration, or blurred images due to one of the three primary light colors not in focus (this isn’t a problem with mirrors that reflect light, but more on that next ish). Opticians quickly discovered that a two-element lens configuration (one the crown glass, and another the flint element) resulted in compensating for a great deal of minimizing chromatic aberration. Images were much more acceptable.

So, with the aforementioned handicap a major consideration, why would someone want to invest in the older design of a refractor? The answer is apparent, when gazing at a bright object such as a planet or our moon: greater contrast. The background of space is inky black, compared to a reflector’s dark-gray image (yes, the reflector design has inherent drawbacks too). A lens is a clear aperture, with no secondary obstruction such as the second mirror essential to the reflector design. Given that, a lens will, pound for pound, outperform a mirror of the same diameter. An eight-inch refractor would simply blow the drawers off an eight-inch reflector, especially when it comes to resolving planetary detail.

A refractor, too, is a simpler design. Taken care of, it is a virtually maintenance-free instrument. Although the lens can require occasional recollimation (alignment), it is very rare, usually necessitated by the lens cell having been removed form the optical tube assembly (never, never do this!).

Refractor telescopes are intuitively easier to learn to use, although the curve for using a reflector isn’t as formidable as it may initially seem (there; I’ve said it…and this author is indeed a confirmed refractor fan!).

A major drawback to a large refractor? Cost and size. Large refractors are HUGE animals, and cannot be easily moved. Hardcore refractor aficionados house these instruments behind their homes, in permanent shelters with either a rollaway roof, or a dome (and, I suspect, are not married).

Some folks by now may be suspecting I have stock in this mail order company, but I don’t…they’re just one of many online, but these guys carry the largest stock of so many brands:

A ten or twelve-inch lens needs a tube anywhere from ten to fifteen feet long. That’s very cumbersome, to say the least. Then you have to consider just what you’re going to mount it on. One “pier” mount goes for over fifteen thousand dollars (just the mount, folks).

These big telescopes are also very expensive (at this level, just the tube assembly itself, or OTA). The first time I saw a few prices, I thought a couple of the numbers had an extra zero as a typo…they didn’t. Observatory-sized ones begin at forty thousand dollars and go through the stratosphere from there. Lens casting and grinding is much more demanding than grinding a mirror.

D & G Optical, a company that specializes in making refractor telescope tube assemblies, will give you an idea of what constitutes a “large” refractor:

So, again, why would someone spend more money than some double-wide shelters cost? Image, image, image. I’ve been told not to make the mistake of gazing through a premium refractor unless I’m prepared to buy one. SO far I’ve been able to resist, as one probably doesn’t exist within a two-hundred mile radius of where I live.

Well…back to Earth, huh? My humble, Celestron C150mm f/8 refractor telescope is about the largest one of this type that yoU can realistically move out to a dark site. It’s still a chore, especiallY the older I get!

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We’ll examine that other type, the reflector, along with its pros and cons, next time.

Clear Skies,

Jesse

So Many Telescopes!

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Like venturing anto any new hobby, there is a multitude of choices. So many makes and models! But telescopes basically fall into one of two types: those that utilize a lens for the light-gathering element, and those that use a mirror for the same purpose.

Refractors employ a simple, and old, design. A compound lens, typically two elements, gathers photons of light and bends or refracts them down the length of the tube to a focal point, where the eyepiece picks them up. Refractors have been around longer. And with good reason: they are sturdy, easier to use, require little maintenance, and will provide a lifetime’s enjoyment, if properly taken care of.

Reflectors, as the name implies, employ a concave mirror (actually a parabolic-shaped curve) which reflects incoming photons of light, and bounce them to a secondary mirror, which in turn reflects them to the eyepiece. All modern, observatory-level telescopes are reflectors (including the iconic Hubble Space Telescope). While somewhat trickier to learn to use, and needing periodic alignment or collimation of the primary and secondary mirrors, reflectors are cheaper instruments, especially as you get into large aperture: “light buckets” (diameter of the actual light-gathering element).

Author's Stable of Telescopes: two refractors in foreground; reflector in the background.

Author’s Stable of Telescopes: two refractors in foreground; reflector in the background.

Advantages and disadvantages of each type?

Refractors, while easy to use (and are almost always the ones you will see in the background as a “prop” in a movie or television show), get very expensive as they get larger. Plus cumbersome. A traditional refractor with, say, an eight-inch lens would have a tube as much as eight to ten feet in length…in other words, you couldn’t transport the monster. It would require a permanent mount, and a shelter to enclose it.

Reflectors can be cumbersome too, but not not nearly to the degree of a refractor. An example of that same eight-inch aperture utilizing a mirror would be a significantly much shorter tube, ranging from as little as one foot in length to maybe five (more on the different types of reflectors later). While this relatively compact size makes for easier transport to a dark site, it also necessitates periodic realignment between the mirror elements. It’s a pretty easy task, but can be daunting for the novice astronomer.

There are other pros and cons associated with each type. Each camp has its enthusiasts as well as detractors. Fans of refractor telescopes swear by their pristine, razor-sharp planetary images, and “ink black” stellar backgrounds resulting from the greater contrast inherent in refractor telescopes. Reflector aficionados, on the other hand, applaud their relatively enormous light-gathering ability, especially when it comes to resolving detail on those “faint fuzzy” deep sky objects (again, galaxies, nebulae and star clusters).

For further analysis of the types of scopes and advantages/disadvantages of each, I cannot recommend a better link than the one following:

https://www.astronomics.com/

Astronomics, a mail-order company that sells a massive inventory of scopes and accessories, has a link on its home page: “How To/More Info”. There is an absolute wealth of unbiased information here. I strongly urge the beginner to do the homework and read up on the plethora of amateur instruments available today.

Decorum in this Forum merely allows me to scratch the surface of this subject!

Till next time,

Jesse

Dawn Patrol

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As I’ve already said, there’s just an allure (at least for me) to pre-dawn stargazing. It’s preternaturally quiet (no conveneint store runs, soyou can pretty much set up along a county road, if you don’t have access to a clearing. No need to keep an eye on the clock. You don’t have to worry about having lost track of the time: when it starts to get light, you pack it in and go home.

But the main reason for me to get out of bed early is those “out of season”constellations (the very same ones that adorn the evening sky, six months later!). If you can discipline yourself, you can catch two entirely different “i-max” shows, evening and morning. If you’re one of those extrememly fortunate observers with a dark site in your back yard, you can wrap up an evening session, drape a grill cover over the telescope, take it inside…get a few hours of sleep, and get right back out to enjoy the pre-dawn parade.

Late September/early October is one of those “sweet” times of the year: Sagittarius and Scorpio are holding court, right after dusk…then mighty Orion and Canis Major rule, just before dawn. It’s truly the best of both worlds (again, late March/early April those two panoramas swap places, evening and morning).

Let’stake a pre-dawn gander at Orion. It’s one of those unmistakable constellations that jumps out at an observer: this winter constellation (meaning it’s well-positioned shortly after dusk, February evenings) is in pretty much the same spot, the wee hours ofthe morning right now. Orion boasts the greatest number of bright stars in any constellation. Three of its stars have proper names:Betelgeuse, Bellatrix, and Rigel, forming three of the four stars constituting its rectangle. But perhaps the most striking feature of this denizen is the three bright “belt” stars in the center of the hunter.

Look closely at the trio. Do you see a faint hazy patch, just below the left belt star? If you have a telescope, turn it that way. That’s the Orion Nebula, one of only two nebulae visible to the unaided eye (the other being the Lagoon Nebula, alluded to in an earlier post, in the “teapot” constellation of Sagittarius).

The Orion Nebula, or M42, is easily the most breathtaking one in the Northern Hemisphere sky. It is visually striking, incredibly detailed. Of course the larger the telescope, the more detail you’ll see…but this is one for every amateur astronomer. You can spend hours absorbing the intricacies of this gem. It’s a stellar “nursery” of hot, young stars.

If you’ve found one of those pristine dark sites from which to observe, you might notice that the same “gossamer curtain” of Milky Way wends its way through the neighboring constellation, Canis Major (A.K.A. the Big Dog). We’reliterally gazing out at the opposite direction of our host galaxy (the center, again, runs through Sagittarius). Impossible to miss is the very bright star Sirius (also known as the Dog Star). Although this constellation hosts nothing so spectacular as the huge nebula in Orion, it is worth sweeping through with a rich-field telescope, or better still, binoculars. There is a plethora of small globular clusters, open clusters, and interesting asterisms. A large pair mounbted on a lightweight tripod will afford you many hours of observing delight in this region.

Next time we’ll take a look at the types of telescopes available. Aren’t you itching to buy one yet?

Clear Skies,

Jesse

Beach Vista!

Another aside, while we’re waiting for the night sky to significantly change.

By now, some of you might have picked up on the fact that, among all of my other amateur proclivities, I’m also a frustrated photographer…I have a modest point-and-click digital camera, whose envelope I have pushed to the uttermost limit with my celestial shots (meager as they are!). But for simple landscape shots it’s hard to beat a humble, dummy-proof digital camera.

Andrews Park, late afternoon.

Andrews Park, late afternoon.

My wife and I love periodic trips to the beach. One of several amenities to be derived from living in lower Alabama is its proximity to the Gulf Coast: Panama City, Destin, Gulf Shores, Pensacola…all can lay claim to a sliver of what some describe as a stretch of beautiful real estate, the Florida pan handle coast!

Author's Better Half, Ready to Relax!

Author’s Better Half, Ready to Relax!

One of our favorite destinations, due south, across Andrews Bay is the park bearing the same moniker. Andrews park boasts a section of pristine, virtually untouched beach…what some describe as “Old Florida”, the way it used to look prior to real estate moguls erecting high-rise condominiums which clutter a larger and larger portion of access to the ocean.

"West" wall, flanking one side of Andrews Bay

“West” wall, flanking one side of Andrews Bay.

Two rock “walls” of boulders flank either side of Andrews Bay. The photo below shows the western side. Throughout any given day, inbound and outbound ships can be seen (seldom heard, though, over the constant surf). Gulls circle, an almost constant breeze rustles the growth among the numerous sand dunes…and the occasional, yet somehow unobtrusive bi-plane flies overhead, a banner trailing, advertising seafood.

These walls are inhabited, too. I managed to catch a brave pair of daytime “bandits”, foraging among the rocks…

Intrepid bandits, nestled among the rock wall (zoom in on center)

Intrepid bandits, nestled among the rock wall. (zoom in on center)

…and the occasional very brave one wouldn’t be above begging up close:

Cheeky Little Guy  and arguably certifiable photographer.

Cheeky Little Guy, and arguably certifiable photographer.

For a nominal fee of eight dollars, you can enjoy this gorgeous park, along with access to uncluttered, pristine beach…and if there’s a more beautiful way to cap off a fantastic day at the beach, I’d like to know what it would be, over sitting back, Pina Coladas, the distant cawing of birds…and the gentle but relentless pounding of the surf:

The perfect ending to one gorgeous day!

The perfect ending to one gorgeous day!

Planetary Dances

Let’s take a brief hiatus from those grey, dim “fuzzies” this time around, to take stock of a few bright objects currently masaquerading as stars: the planets Mars, Saturn, Venus and Jupiter.

Planetary conjunctions are somewhat like family reunions. It’s common to see a couple of them close together, but to get three or more to gatherin one spot at the same time? Rare. It would be very nice if these guys could put aside their petty differences and mingle more than once in a blue moon (forgive the phrase!), but again that just doesn’t happen very often. So we’ll take the hand of celestial cards that have been doled out to us.

Currently Saturn and Mars are highlighting the evening sky, both fairly close to each other, just to the left of the head of Scorpio. Until recently, Mars was easy to discern: when Earth periodically “laps” the red planet, it appears to us as a very bright, ruddy “star” (the real red giants, Antares and Betelgeuse, don’t come close for brightness, when Mars is at opposition, or as close to Earth as it gets each time we pass it). These evenings, Earth is the fleet runner in lane 3 pulling away from sluggish Mars in lane 4; ergo, Mars is fading in both brilliance and color. It’s still distinguishable from Saturn because of the slight difference in colors between the two. Saturn is more of a “sickly” yellow, again currently rubbing elbows with our nearby neighbor.

Once you’ve identified which is which, turn a telescope on one of them. I recommend a scrutiny of Mars first, because it’s no longer at its best, having shrunken in apparent diameter due to our increasing distance from the red planet. It’s still interesting, appearing as a pink-orange little ball. Mars, by the way, will present a spectacular appearance during 2017, as Earth will catch up to it (“lap” it!) coinciding with Mars being almost as close to the sun as it gets during its orbit; hence, it will appear about 20% larger than this time around.

The reason I suggested a perusal of Mars first? Because ANYthing after viewing Saturn is anti-climactic. The ringed planet is just stunning, almost all of the time. It’s so distant from us that it almost makes no difference where it is in relation to us. The rings are a jaw-dropping sight, under medium to high magnification. During optimum seeing conditions (no upper-atmospheric turbulence), you can see the major division in the rings that has adorned so many photographs over the decades. Superlatives fail. Pictures don’t do it justice. You have to see this planet through a telescope to appreciate its majesty.

Now, the fun part: Jupiter and Venus. They’re currently visible just before dawn. Yes, that means rolling out of bed early (most amateur astronomers are masochistic, right?).

Jupiter is another show-stopper: it might be able to follow Saturn, but IMHO not quite. Jupiter’s forte is its size, detailed cloud belts and striking moons. Io, Europa, Callisto and Ganymede-also known as the Gallilean satellites-are almost always on display. If you onl spy three of them, come back an hour later when the fourth will have emerged from behind the planet! These guys do a constant dance, shifting positions several times a night.