Monday, November 5, 2018

Last night I saw Neptune...

... and thought about horizons.

("Last night" was actually last Saturday, but I did start to write this on Sunday.)

I grew up in Arizona in the 1950s and 60s. I took for granted that the horizon was 30, maybe 40 miles off, and the sky overhead was an infinite expanse of blue, blue, blue. I have vivid memories of topping a rise on one of my many family trips "up north" (to Payson or Flagstaff) and seeing revealed to my eyes range after range of mountains receding into the distance, each one 30 to 40 miles further away that the one in front of it.

How different it is here "back East" (as we used to say). Here the horizon is seldom more than one or two hundred yards away. On rare occasion (usually on a highway when you're paying no attention to such things) you might actually see a mile or more in front of you, but that's not so often and you're almost always distracted from enjoying the view by the need to watch the traffic right next to you.

I remember (when I was old enough to see the humor in such things) laughing whenever the weatherman said that "visibility is 10 miles at BWI" when I could plainly see the Moon overhead. I wanted desperately to shout at the radio, "No! Visibility is one quarter million miles!"


Neptune, as seen from Voyager II

Neptune is not the easiest target to find in the night sky, especially for someone like me who resolutely (some would say fanatically) eschews any and all electronic or mechanical aids to observing. My "finder scope" is a pair of 8X56 binoculars hanging round my neck. And, no matter how faint the objective, I stick with starhopping as my one and only method of navigation. Last night, it was find the Water Jar in Aquarius. From there, it was a fairly easy slide down to Lambda Aquarii, a star on the ragged edge of naked eye visibility in light polluted suburban Maryland. Then scan westward until I have a kite shaped asterism centered in my field of view. Neptune (in my mirror imaged view) hung off the left side - a tiny blue dot with just a hint of a disk. Switch to a higher powered eyepiece and the non-stellar nature of the dot became more apparent.

A quick check with the ephemeris and one finds that Neptune is currently two and three quarter billion miles from the Earth. Knowing full well that I will never see Pluto or any other Trans-Neptunian object with even my largest telescope (a 102mm refractor), I acknowledge that this electric blue dot in my eyepiece is the furthest thing I will ever see within our Solar System with my own eye. And I cannot tear myself away from it. I care not that there are hundreds of DSOs clamoring for my attention on this rare evening of perfect conditions. I can't get enough of this sight, this "dot".

I don't care how silly this sounds, but 2.75 billion miles I can understand. But interstellar distances? They defeat me. Oh, it's easy enough to say the words, "This star is 840 light years away," but we all know that such words don't really mean anything to us. The distance is simply too great to comprehend. And don't get me started on intergalactic distances!

I think I spent maybe all of 20 minutes drinking in the view and pondering what I was seeing. Then it was on to some double stars that I really wanted to observe that evening. But it was Neptune that haunted my thoughts all the way home, and Neptune that first came to mind the following morning.

We don't think much about horizons in suburban Maryland - not when houses, buildings, and trees restrict our view to a few yards around us. Stargazing can be a useful corrective to our everyday perspective on things.

Monday, October 29, 2018

Bring it on Home

Considering the appalling events of the past few days in our country, I cannot in good conscience continue to exist as though I am not part and parcel of the world around me. I cannot pretend that it is possible to isolate myself from what is happening to us. If our "hobby" of amateur astronomy has nothing to say to the terror and pain around us, then to hell with it! But... it has a lot to say, a lot to teach us, a lot to teach the world.

The following is a reposting of something I wrote several years ago for my now defunct blog, Celestial Pilgrimage. It is more relevant now than when I first posted it:

Everywhere I look in the sky, no matter what the direction nor how distant the object, whatever I see is either acting on or being acted upon by something else. It is either orbiting something else, or is itself being orbited. It is either attracting something else, or is in turn being attracted. It is either illuminating its surroundings, or is itself being illuminated. Nothing is alone; nothing exists in isolation. There is a bedrock fundamental something to be discovered here, and double stars are perhaps the clearest visible illustrations of whatever this is to the amateur astronomer.


Albereo

But allow me to digress a bit. I am forever amazed by how much the whole of my subsequent life has been influenced by the relatively short time I spent in the Army (1975-1979). I truly believe that I learned and grew more in those four years than in any other comparable length of time. From insignificant mannerisms (how I stand, what I do with my hands while walking, the fact that I always start off on the left foot) to fundamental ways I view the world, I keep finding bits and pieces of my Army experience down there in my subconscious, nudging (or pushing) me in one direction or another.

One really good example is foxholes. One of the first things we learned in Basic Training at good old Fort Ord, California, was the correct (that is, the Army’s) way to dig one. And if you have some picture in your mind taken from a host of cheesy WWII movies (hole in the ground, head and rifle sticking out) – get rid of it now. What we were taught was the DuPuy foxhole, named after the general who invented it. DuPuy had studied the carnage of Vietnam (remember, I enlisted only about 3 months after the fall of Saigon), and realized that everyone had been doing it all wrong ever since, well… ever since ever. The problem with firing out of a hole in the ground was that an advancing foe could fire right back at you. Thus the high casualty rate on both sides in a defensive battle.


General DuPuy (right) with Westmoreland in Vietnam

What DuPuy came up with was a system of mutually supporting two-man foxholes. “Buddy Teams” of two soldiers would each dig their own pit, piling all the excavated dirt directly in front of the hole, completely blocking one’s view straight ahead. When you were finished, you could fire diagonally to the left or to the right, but immediately in front of you was this great earthen berm, higher than your head. The end result was that, in a line of these DuPuy “Defensive Fire Pits” (to use the official term), each buddy team was responsible for protecting the team to either side of them, while their own defense was left in turn to those teams. To work, the system required complete trust between the teams. You yourself could do absolutely nothing to protect yourself, and concentrated all your attention and efforts on defending your neighbors.

Take a moment to ponder this. There is a really profound principle at work here. One that I think goes to the very core and fundament of our being - of the universe itself. It is the indispensable principle behind How We Must Live. As the poet Charles Williams so beautifully put it:

This abides – that the everlasting house the soul discovers is always another's; we must lose our own ends; we must always live in the habitation of our lovers, my friend’s shelter for me, mine for him.

The consequence of ignoring this is not just selfishness. It is not just missed opportunity or a life sadly lacking in color or meaning – it is a violation of the very nature of reality. To attempt to live for one’s self is an exercise in futility – you will fail.

One of the most awesome passages in the New Testament (for me, at least) occurs near the end of the Gospel according to Mark. Christ has been crucified, and various passersby taunt Him, asking why He doesn’t “save yourself and come down from the cross”. They conclude with the scoffing remark, “He saved others, Himself He cannot save”.

Wow. Read that again. What was meant as a contemptuous dismissal, as a cynical comment on apparent failure, turns out to be the very key to The Meaning of Life itself. We cannot save ourselves – we must rely on others. And it is up to us in turn to save them. This is what it means to be a Human Being. When we fall short of this principle, we fall short of and even deny altogether, our very Humanity.

Think about that, the next time you are admiring a particularly beautiful double star... or the next time someone shoots up a House of Worship out of fear of the "other".




Sunday, October 28, 2018

Queen of the Gods!


Our best image of Juno, showing its highly irregular shape. 
Juno is 145 miles across at its widest.

Exactly 2 weeks from today will be your best chance to observe the third asteroid to be discovered (although by far not the 3rd largest) - Juno, named for the mythical wife of Jupiter.

Bottom line on top: This will be Juno's most favorable opposition since 2005, and will not be this close to the Earth again until 2031 (by which date I will either be 79 years old, or dead). This is due to Juno's highly eccentric orbit, worse than Mars, which makes for some oppositions being far more favorable than others. (See illustration below.)



Although assigned the number 3 due to its order of discovery, Juno is actually only the 11th largest asteroid (exceeded by Ceres, Vesta, Pallas, Hygeia, Interamnia, Europa, Davida, Sylvia, Cybele, and Eunomia). Where it does excel, however, is in its high surface reflectivity, which with an apparent magnitude of 7.5 makes Juno (at opposition) brighter than Neptune. No wonder it was one of the first asteroids to be discovered! Juno was even listed amongst the planets for 38 years before being demoted from that lofty status to mere asteroid in 1845.



Although opposition does not occur until the 17th of November, the 11th will be your best chance of actually seeing Juno, due to its near miss of naked eye star 32 Eridani (magnitude 4.46) on that night. Try to spot it on the 10th (weather permitting, of course), and take a second look on the 11th. See which star in 32 Eridani's vicinity has moved since the night before - that's Juno! And if conditions permit, go for the 12th as well. After that, Juno will increasingly blend in with the anonymous mass of similarly looking points of light which are, of course, the background stars.

Useful hint: Sketch the stars near to 32 Eridani each night as accurately as you can. That will aid you immeasurably in positively identifying Juno, since it will be the only "dot" that moves night to night.

Juno will be bright enough to observe this opposition uning only binoculars - no telescope required. In fact, that is my intention - to spot Juno using only my 8X56 binos. If that does not work, then and only then will I resort to a telescopic search.

Monday, October 22, 2018

The Truth, the Whole Truth, and Nothing But the Truth

Science fiction writer Arthur C. Clarke once had a character in one of his stories (I wish I could remember which one, but I cannot - believe me, I've tried.) looking in awe at an ultraviolet (or maybe it was an X-ray) view of the Earth as seen from the Moon. Staring back and forth between the image and the actual Earth in the lunar sky above him, he finds himself lost in a philosophical reverie. Which is the Earth's "true" appearance, he wonders.

The fact is, they both would be. What we see with our eyes is indeed a valid picture of reality, but not the only one. Notice I did not say there were two realities - there is only One Truth - but rather there are two (in fact, many) ways of looking at that one reality.

Here is an image of Pluto taken by the New Horizons spacecraft, as seen in "natural color, that is, as it would appear to a hypothetical astronaut reproducing New Horizon's flight plan.



So. That's pretty much what you or I would see, were we ever lucky enough to travel so far. But here is the same image with "enhanced color". That is, the colors are true, but somewhat exaggerated to bring out fine detail.



Is that less real than the first image? Not really. All the person processing the image did was to compensate for the limitations of human eyesight. He hasn't added or subtracted any data - just enhanced it. All those colors were present in the first image. They were just too subtle for the eye to pick up without assistance.

But there are other wavelengths that human eyesight is totally incapable of ever seeing. We're just not constructed for it. But that does not mean those wavelengths are any less real. Below we have a view of Pluto in the infrared. The imager has selected colors that can be seen by us humans to represent those we cannot, and here is the product thereof.



And next is an image where the color scheme is completely arbitrary, each one representing a different type of surface mineral. Scientists use such "false color" images to see patterns which would otherwise be invisible to us.



And how about this image, showing the unlit, night side of Pluto, surrounded by its atmosphere?



But are such global images really the "truth"? Do we need to be close up to see what Pluto really looks like? After all, imagine you were looking at a picture of a person taken from a distance of one mile away. You might be able to make out that it was indeed a person (and not, say, a tree), but could you really say you knew what the person looked like?

Here is a relatively close up image of Pluto, showing its rugged terrain and mountains made of pure ice water.



And here is one of the closest, most detailed images taken by New Horizons, showing features as small as what would be individual buildings on the Earth. (As always, click on the image to get full resolution.)



At this point, you can either throw up your hands and say there is no "true" view of the planet Pluto, or...

... or, you can realize that Reality is damned complex, and the best we can ever do is tug at the edges of it. Now please don't get the totally false impression that somehow what we see with our own two eyes is somehow "not true". Far from it! It is as true as any of the other images we just perused. It's just not the Whole Truth.

Thursday, October 18, 2018

Averted Imagination

One of the oldest jokes in amateur astronomy is to (laughingly) accuse someone of using "averted imagination" while observing some really difficult object, such as a super faint galaxy or an impossible to split double star. Heck, I've on occasion accused myself of doing so. But truth to tell, it's often hard to delineate the line between desperately trying to see something and just plain imaging that you are successful at doing so.


Sirius and Sirius B (off to the lower left)

Case in point: last winter I was convinced I had finally, after numerous attempts, seen Sirius B (the white dwarf companion to Sirius) through the eyepiece. It didn't stay in view, dang it, but kind of "popped" in and out - the tiniest imaginable point of light nestled right up against the overpowering glare of Sirius. I even stepped away from the telescope and returned to see whether it was still there. And it was... But alas, when I did some calculations at home later that evening (science ruins everything!), I had to admit that whatever I was seeing could not possibly have been Sirius B - it was on the wrong side! (And yes, I did take into account my telescope's mirror imaged view.) So I sadly had to conclude that I was not only using averted vision to see my mystery object, but averted imagination as well.

So yes, an overactive imagination can be a real problem. It is likely a major component of why Percival Lowell and his contemporaries kept seeing all those canals on Mars. (I myself have seen them twice, despite knowing full well that they do not exist!)

But there may be an equal and opposite error possible.


A City on Mars, as imagined by artist Leslie Carr (1951)

Take a good look at the illustration right above this paragraph. I found this in a most remarkable book by science popularist and science fiction writer Arthur C. Clarke, The Exploration of Space (published in 1951, the year before I was born). It supposedly depicts a future settlement on Mars, but when you think about it, what it actually depicts is a quite unremarkable 1950s midwestern American city. Just look at that architecture! In fact, why is there architecture at all? You're under a dome - what need for buildings? And the cars! The dome looks to be all of 400 yards across. Just where are you going to drive? Plus, it would be sheer insanity to waste so much valuable (and limited) real estate on something as useless as roads. Finally, I wish I could see the pedestrians up close. I am sure they would fit in unnoticed in any random crowd of shoppers in downtown Indianapolis.

Now I am not pointing these things out to make fun of the illustrator - far from it! But what I am saying is there was a Failure of Imagination when designing the image. The implications of colonizing Mars were not thought through, and there was a (likely) unconscious assumption that the styles and norms of 1950 would not be out of place in 2150 (or whenever this future city was supposed to be built).

Another and far more glaring example of such a failure of imagination is when the news media inevitably announce every new discovery of an Earth-sized exoplanet as a "Second Earth", neglecting the too numerous to count differences (or possible differences) between said exoplanet and our home body. It seems that all that counts in such reporting is the mass of the planet and the distance from its sun. But there are a myriad of other qualifiers that must be met before we can even begin to speak of an "Earth 2", among them being age, atmosphere and water content, plate tectonics, possession of a moon, a rotating iron core (to create a magnetic field), prevalence of asteroids and comets in the system, distance from gas giants (if any), axial tilt and rotation rate... failure to match in even one of these traits  means we might as easily be looking at a second Venus as a second Earth.

Do we do the same thing when seeing some Deep Sky Object for the first time? Do we assume without thinking about it that "You've seen one globular cluster, you've seen 'em all!" and fail to see that M13 doesn't look at all like neighboring M92?

So we really ought to approach each new object with a mental clean slate - no preconceptions, no assumptions. These are the bad habits that prevent us from seeing subtle differences that ultimately make the difference between one genus and species and another.

Monday, August 20, 2018

Don't Hate the Moon!



Some years back, a fellow HAL member (who shall remain nameless - he knows who he is) quite calmly stated at a Carrs Mill impromptu star party, "You know, if I could shoot down the Moon, I would." It brought to mind the old Looney Tune character, Marvin the Martian, who was always saying, "I'm going to blow up the Earth! It obstructs my view of Venus."

And yes, truth be told, the Moon does "obstruct" our view of deep sky objects - especially the fainter ones. In some ways, it's the ultimate in light pollution. All those moonlight sonatas and syrupy old love songs about walking in the moonlight... "Bah, humbug!" is the reaction of all too many amateur astronomers. I especially hear this reaction when one of our all-too-rare clear nights coincides with a full or near-full Moon. (There almost seems to be an inverse correlation between how much Moon is up there and the percentage of cloud cover.)

But, please. Let's not throw out the baby with the bathwater. In and of itself, the Moon is one of the most rewarding objects up there to observe (see my postings on this subject from Nov. 30th and Dec. 2nd, 1017, entitled "Explorers!").

Now this very upcoming weekend is a case in point. It appears that we're going to be presented by the weather gods with at least 5 clear nights in a row (Wednesday through Sunday), with a Full Moon on Saturday. So you have a choice. You can either stay indoors and mope, crossing your fingers that the skies will be clear for the next New Moon, or you can use this opportunity to take a look at some sadly overlooked lunar features over on the seldom observed "left side" of the Moon's Earth-facing hemisphere. They are far too many to list outside of a textbook, but allow me to highlight 1 or 2 per evening.


The crater Aristarchus and surrounding terrain, as seen by Apollo 15 astronauts

Wednesday: The brilliant crater Aristarchus (brightest spot on the nearside hemisphere) will just be coming into view, around about 10 o'clock (2 o'clock in a mirror-imaged view). If you're patient enough, you can actually watch the endlessly fascinating surrounding terrain emerge into the sunlight, as dawn sweeps over it over the course of the evening.


Schiller

Meanwhile, down in the southern hemisphere, the dramatically misshapen crater Schiller is close to the terminator. This bizarre feature was created by a object striking the Moon at an extreme angle - almost missing it altogether.

Thursday: Go back once more to Aristarchus. The entire region will be in sunlight by this time, and the crater itself will be almost too bright to look at.


The Marius Hills, as imaged by the Lunar Reconnaissance Orbiter
(Click on image to see full resolution.)

Further south at approximately 9 o'clock (3 o'clock in a mirror-imaged view) and not far from the terminator, you'll come upon one of my personal favorite areas of the Moon to observe - the Marius Hills. This is a region of literally hundreds of volcanic domes and related features such as collapsed lava tubes. I remember well the first time I laid eyes on this feature, not knowing what I was looking at. Through the 80mm scope I was then using, it appeared that the Moon had either a bad case of acne or else goosebumps! The low elevation domes naturally show up best when they're smack on the terminator. They rapidly fade into invisibility as the shadows disappear just hours after dawn. So take a look while you have the chance!


Reiner Gamma, as imaged by Lunar Orbiter 4

Friday: For lovers of mystery and enigma, the Moon on Friday presents Reiner Gamma, one of the strangest features anywhere on its surface. Astronomers still do not completely understand how this feature originated, but they have some pretty good guesses. First of all, it is not a topographic feature. If you were standing right on top of it, you'd never know it was there. There is not an inch of elevation difference between its light and dark swirls, it being entirely an albedo feature. But orbiting lunar probes have detected a powerful, localized magnetic field directly under Reiner Gamma. It is believed that this field has charged fine dust particles in the regolith with static electricity, which has caused them to line up like iron filings around a magnet, like we used to do in high school science classes. (Do they still do that?) Reiner Gamma is found to the southwest of the Marius Hills.

No one knows why the magnetic field is there, making Reiner Gamma all the more intriguing.


Mare Orientale, as imaged by Lunar Orbiter 4

Saturday: To top things off, if you look over at the lunar horizon at about 8 o'clock (4 o'clock if your scope gives you a mirror-imaged view) you can catch a glimpse of the edge of what is possibly the most spectacular feature on the entire surface of the Moon, both near and far sides - the Mare Orientale. This is a truly gigantic impact basin (nearly 600 miles in diameter) although from the Earth we can only see its extreme eastern parts. Sometimes, you just have to take what you can get!

Sunday, August 12, 2018

Recharging my Batteries


This year's Stellafane was a landmark for me, in that this was the first year when I truly could not remember for certain how many of these I've attended. I have to admit that I'm an addict. I started going up to Stellafane several years ago when I was fully intending to move to New England, and thought it would be the perfect way to get acquainted with the local astronomy clubs. Well, here I am still in Maryland, and seemingly here to stay. But every summer, I feel the draw of the Vermont mountains, with their dark skies and quaint little towns filled with wonderful restaurants and totally unique art galleries and local crafts shops. I'm always done for the year with my Christmas shopping after a week in Vermont - and this year was no exception. I think I contributed about 700 dollars to the state's economy.

As for Stellafane itself, it's an opportunity to hobnob with hundreds and hundreds (there were as many as 1000 in attendance this year) of like-minded astronomy fanatics. Some of my favorite moments at various Stellafanes have occurred not on the observing field, but in the food tent or up at the Clubhouse, meeting perfect strangers and talking literally for hours about viewing conditions back home, our local clubs, our own and others' equipment, our observing triumphs (and failures), our children and/or grandchildren, the Drake Equation, plate tectonics, hot Jupiters, red dwarfs, meteorite hunting in New Hampshire, World War II, global warming, how amateur astronomy is going to hell in a handbasket, and ten million other topics.

But the meat and potatoes of any star party, whether it be a Carrs Mill Impromptu or a major regional like Stellafane, is what did you see. We had one superb night this year (Thursday), one so-so (Friday), and one cloud out (Saturday). So Thursday was the "Make or Break" evening, as far as observation went. And in my books, it all by itself was worth the 8 and 1/2 hour car ride north.

On Thursday night, I observed:

Venus
Jupiter
Saturn (saw 5 moons)
Mars (could make out the polar cap and Syrtis Major)
The Lagoon Nebula
The Trifid Nebula
The Small Sagittarius Star Cloud (M24) - came back to this again and again!
The Swan Nebula
The Eagle Nebula
The Wild Duck Cluster (M11)
The Dumbbell Nebula
M71 (globular cluster in Sagitta)
The Coathanger
61 Cygni (double star in Cygnus)
Albireo (double star in Cygnus)
Omicron Cygni (triple star in Cygnus)
Barnard's Star
B111 (dark nebula in Scutum)
M22 (globular cluster in Sagittarius)
M4 (with binoculars)
HD 162826 (with binoculars)
Several Perseid meteors (2 of them spectacular!)
The star fields of Cygnus (it spoils it if you look for anything in particular - just look!)
M6 (open cluster in Scorpius) - the last thing I looked at, just before tearing down
The Milky Way (just looked away from the eyepiece and drank it all in)
6 or 7 satellites
The International Space Station

The scope I used that night was my 102mm Stellarvue refractor with a variety of eyepieces.

The conditions were far less promising on Friday evening, so all I set up was my 60mm refractor, because I wanted to be able to tear down at lightning speed if I decided it wasn't worth hanging around. Besides, I could always look through other folks' monster Dobs if I felt like it! That night I had my best eyepiece view this opposition of Mars. Absolutely amazing how big it appeared. I know it wasn't, but damn if it didn't seem bigger than Jupiter. But Mars looked best of all naked eye, like a baleful red eye rising over the tree line. I couldn't get enough of it.

On Saturday, I woke up to wall-to-wall cloud cover and off-and-on rain. But it didn't bother me. I hiked up to the Stellafane Clubhouse and had some great conversations with the people who had entered their scopes into competition. Met one gentleman who had attended every Stellafane since the year I was born (1952)! He talked to me for half an hour about how one tested a newly ground mirror for accuracy, and showed off some equipment used in the process which he had designed and built himself. I admired the work of Sara Schechner who makes astonishingly beautiful astronomically themed quilts (her day job is the David P. Wheatland Curator of the Harvard University Collection of Historical Scientific Instruments). I ran across two young women from Roland Park in Baltimore, attending their very first Stellafane, and discussed the pros and cons of urban astronomy. I spent a good hour with a 77 year old man (whose name I never did get - he wasn't wearing his name tag) who told me his life story, occasionally with tears in his eyes. He was so interesting, I wish I could have taken notes, but that would probably have been rude. I saw (but did not speak to) Al Nagler as he walked by my telescope on the observing field. I hope he noticed my 9mm Nagler eyepiece!

(True Story: A couple of years ago, I was sitting right next to Al for a good 30 minutes during lunch at the food tent, and had no idea who he was. In my defense, I hadn't the slightest idea at the time what Al Nagler looked like. It wasn't until I was getting up to leave that two other people walked over and said hello to him, thus enlightening me to my now totally wasted opportunity to speak with one of my heroes.)

All in all, a great star party, and definitely not my last Stellafane. I look forward to the day when I can bring my now 5 year old granddaughter along with me. (Of everyone in my extended family, she is the most interested in (dare I say obsessed with?) astronomy.)

So here I am, back in light-polluted suburban Maryland, batteries recharged and ready for another year of stargazing!