send e-mail to A Voyage To Arcturus (note: Spam Arrest is on, so a one-time-only confirmation will be requested)
[ 20040729 ]
Original Science News Reporting
Graze on over to Pharyngula for some first-class reporting on SDB 2004, from which Dr Myers just returned. Start here and work your way up.
(The one time I did something like that, from LPSC 33 in March 2002, it wore me out; the results are here, for those interested -- once you're there, scroll down for more.)
Jay Manifold [9:23 AM]
[ 20040725 ]
Saw a rumor over on the ASKC Yahoo! group: "Looks like tonight has an excellent chance of aurora. A big CME is coming in on top of fairly high activity so there is a good chance of seeing something."
A CME is a Coronal Mass Ejection. I dug around and found the Space Environment Center webpage; excerpts from the forecast (note that the text on that webpage is updated frequently) appear to indicate that there's a better chance tomorrow night:
Region 652 (N08W35) produced four M-class events, the largest - an M7/2B flare at 25/0551Z. This flare had associated moderate centimetric bursts, including an 819 sfu Tenflare. A Type IV radio sweep also accompanied this flare. No LASCO imagery was available, but it is likely that an Earth-directed CME was associated with this event.
CMEs associated with today's M7 and long duration M1 flares will likely impact the geomagnetic field on 27 July and produce periods of major storming.
Note that these dates are UT, for which midnight is at 7 PM CDT. So tomorrow night could be ... interesting. The forecast for tomorrow night also predicts (for middle latitudes) a 45% probability of a "minor" geomagnetic storm and a 30% probability of a "major" storm.
This excellent background article notes that
If a [solar] flare is analogous to an interplanetary thunderstorm, a CME initiates an interplanetary tsunami—a flood of billions of tons of protons and electrons bursting from the sun that is capable of massive interference with any flux-sensitive apparatus it happens to encounter.
Might be worth driving north of town a ways to catch it ...
UPDATE: For locals, moonset is around 1 AM tonight and a little after 1:30 AM tomorrow night. Unfortunately, this is important, because the Moon's phase is waxing gibbous, which could interfere with observation. Maybe the thing to do is get up in the early morning hours and drive north; civil twilight begins about a quarter to six, so you'd want to be in place by (yikes!) 5 AM or so.
Jay Manifold [7:25 PM]
[ 20040722 ]
Supposedly inspired by me, though I can only vaguely recall suggesting the first song, has been composed by Alan Henderson.
Jay Manifold [9:38 AM]
[ 20040721 ]
A post (and its comments) which succinctly captures what Andy Cline is up to is here. Graze and be enlightened ...
Jay Manifold [6:28 AM]
[ 20040720 ]
What I said then. Also, relive the event through these panoramic shots, and graze on over to YourSky to recreate the scene for 02:56:15 UT on 21 July 1969 (source) at your location -- which, in my case, puts the Moon, just shy of First Quarter, low in the west-southwest near Spica, and Mars almost due south in Scorpius, near its rival in color, Antares ("anti-Ares"). The sky was clear that Sunday evening in KC; I remember the Moon well, and think I remember Mars, and certainly remember Vega nearing the zenith. It was a few minutes before 10 PM local time when Neil Armstrong stepped off the LM.
UPDATE: Horseman of the Arcturcalypse Alan Henderson has a fine photo essay for the occasion.
Jay Manifold [5:59 AM]
Forget June. I meant to say September. Hey, maybe I'll get to join that Human Abductee Resistance Force and learn to fly a UFO.
Sheesh.
Jay Manifold [5:37 AM]
[ 20040719 ]
-- well, appears to fly by Jupiter, from a vantage point near Liverpool, UK, on the evening of Tue 25 May. Taken from this remarkable website, which has several other short clips as well. Notice in particular the 1 Oct 03 shot, which at a range of 450 km appears to have a resolution of as little as 2 meters, and that's with only an 8" telescope! (See this earlier post for a suggestion about a practical application of this sort of thing, though with rather larger instruments.)
And don't miss this spectacular multiple exposure of the ISS crossing the Sun's disk during the Transit of Venus. (Both links courtesy of the ASKC's Yahoo! Group.)
Jay Manifold [3:56 PM]
Ask why the Saudis are allowed to kill thousands of Americans and still get the kid-glove treatment, and you’re told the magic word: oil. Here’s my answer: blow it out your Medicine Hat. The largest source of imported energy for the United States is the Province of Alberta. Indeed, whenever I’m asked how America can lessen its dependence on foreign oil, I say it’s simple: annex Alberta. The Albertans would be up for it, and to be honest they’re the only assimilable Canadian province, at least from a Republican standpoint. In 1972, the world’s total proven oil reserves added up to 550 billion barrels; today, a single deposit of Alberta’s tar shales contains more than that. Yet no Albertan government minister or trade representative gets the access in Washington the Saudis do. No Premier of Alberta gets invited to Bush’s Crawford ranch. No Albertan bigshot, if you’ll forgive the oxymoron, gets Colin Powell kissing up to him like “Crown” “Prince” Abdullah and “Prince” Bandar do. In Washington, an Albertan can’t get …well, I was going to say an Albertan can’t get arrested, but funnily enough that’s the one thing they can get. While Bush was Governor of Texas, he even managed to execute an Albertan, which seems to be more than the Administration is likely to do with any Saudis.
Jay Manifold [6:06 AM]
[ 20040718 ]
What an Observing Session Should Be
It should leave the observer "... mellowed to that tender light/Which heaven to gaudy day denies," with proper awareness of terrestrial scale, and appreciation for that immense array of structures, systems, colors, voids, and sheer abundance which hangs suspended, seemingly, above us all; not only on clear and moonless nights, but every moment of our lives, though shrouded by Rayleigh scattering and veils of cloud droplets.
Last night certainly sufficed. Sky transparency was poor -- not an unknown phenomenon during summer in the Midwest -- but seeing, that is, the stability of the atmosphere, was rather good. And the food at the star party I attended, in Miami County, KS, about three-quarters of an hour's drive south-southwest of stately Arcturus manor, was superb, thanks to the host. As an added bonus, previously known reader Tony Ortega and his wife attended; his telescope, a 10" Newtonian on an equatorial mount, easily outperforms my 13" Dobsonian, having been much more carefully maintained and extensively accessorized. Also, Tony used to work in a planetarium, so he not only knows what he's doing but comes preloaded, as it were, with phrases for retaining an audience's attention and implanting memories. Whereas my descriptions tend toward the literal and technical.
The only notable find I made was Pluto, and though I'm certain it was in the field of view (thanks to an excellent finder chart from Sky & Telescope), pointing it out to anyone else proved effectively impossible. I found Neptune too, but the haze was getting pretty thick by then, so it was once again not easy to share. Otherwise I mostly just pointed the 'scope at bright stars, to show colors -- a big light bucket like that will get the cone cells in your retina working -- and at a few deep-sky objects (M13, M31, etc).
But in Tony's 'scope, we saw -- in addition to the usual summer-sky attractions -- such objects as M71, a fine globular cluster in Sagitta, and the variable star S Cephei, which we agreed was the reddest star we'd ever seen.
Now, about that "proper awareness of terrestrial scale":
If the highest mountain on Earth were surrounded by a flat plain at sea level, or the ocean itself, the horizon as seen from its summit would be less than one-thousandth the distance from Earth to the Moon, and the area enclosed by that horizon would be less than a fiftieth that of the Moon's visible hemisphere.
Mars, at its closest, is well over a hundred times farther away than the Moon; a typical asteroid whose size and shape are being measured by occultation is at a thousand times lunar distance; and Jupiter is half again as distant as the main asteroid belt. A glance at Jupiter through even a small telescope reveals an immense world whose surface area, as Arthur C. Clarke so memorably wrote, compares to Earth's as our entire globe compares to India.
Six times farther out than Jupiter, the last major planet, Neptune, revolves in an orbit so large that it has yet to complete it once in over a century and a half since its discovery. Yet if this orbit were the size of an American cent, the very nearest star outside our Solar System would be nearly the length of a football field away. The nearest star most people have ever seen is twice that distance; and the star perhaps most often noticed by the greatest number of human beings, thanks to its position near the zenith on late summer nights in north temperate zone of Earth, is six times as far away: over half a kilometer, a third of a mile, with the Solar System the size of a penny. That star is nearly fifty times brighter than the Sun; coincidentally, our Solar System is moving toward it at the stately pace of twenty times the speed of a rifle shot.
But these are only the first steps of a journey into the summer sky. The Milky Way appears split by a dark lane empty of stars, which is actually a cloud of intragalactic dust in the foreground, nearly a hundred times Vega's distance. The star clouds of our galaxy, unresolved until Galileo turned his telescope upward, are correspondingly farther away; a conspicuous one in Sagittarius is over one-third of the way to the center of the galaxy itself, hidden by more dust clouds that block the transmission of visible light.
Later, when the Square of Pegasus is high enough in the east, one can follow the curve of stars arcing away from its northeast corner. Two stars out, turn right at b Andromedae, find m Andromedae, and continue on the same distance. That smudge is the nucleus of another galaxy, at least as large as our own, and two hundred times farther from us than the Sagittarius star cloud, itself the most distant object visible to the unaided eye in our own galaxy.
Here we reach the limits of non-telescopic observation, but a modest telescope will reveal, for example, the giant elliptical galaxy M87, thirty times farther away than the Andromeda Galaxy; and will of course begin filling in the otherwise-invisible bounties of nearer space: the craters and moons and starfields first sketched by Galileo; the planetary nebulae, open and globular clusters, and star-forming regions catalogued by Messier; the new worlds discovered by Herschel, Adams/Leverrier/Galle, and Tombaugh.
Next Saturday night, I will be on duty at Powell Observatory. Local Arcturus readers, known or unknown, are encouraged to visit. The program (page down), "Astronomy 101," begins at 8:30 PM; turning to this handy application, we find that sunset is at 8:36 PM, civil twilight ends at 9:06, and the Moon will be precisely at First Quarter.
UPDATE: Tony writes ...
"It's funny that your link about S Cephei ends up [at] an observation by Steve Coe.
"When I was in Phoenix, Steve was one of the regulars of the local observing scene -- and quite a character. The Vekol Road observing sessions back then were sometimes a who's who of big-time amateur astronomy names. Tom Bopp, Steve Coe, Tom Polakis (one of my best astronomy friends and a contributor to Astronomy magazine), Chris Schur (one of the best photographers in the country) and other notables.
"Some of them took their hobby very, very seriously (Coe, Schur), and others were simply wonderful to observe with (Polakis and many others).
"Man, I miss those desert skies!"
Jay Manifold [7:29 PM]
[ 20040716 ]
-- the South Pole Traverse Project, that is, which I originally read about in PM Network magazine (article not online).
Just as long as they're not paying for it with these ... (thanks to Exclamation Mark for the link).
Jay Manifold [12:39 PM]
Fifty-nine years ago: a day that changed the world forever. May such breakthroughs always happen first in a land of liberty.
Twenty-nine years ago: the only launch I've ever seen in person -- the last such event brought to us by the generation of Manhattan and Apollo.
Jay Manifold [10:24 AM]
"You can have peace. Or you can have freedom. Don't ever count on having both at once."
-- Robert A. Heinlein
UPDATE: Lots of discussion, including some rather bellicose ideas being offered in response. I modestly suggest wearing something like this on your next flight.
Jay Manifold [10:06 AM]
[ 20040715 ]
US leading world science, says The Scientist:
[The United Kingdom's chief scientific advisor, David A.] King's" study used the ISI index of more than 8000 journals in 36 languages. His analysis included 31 countries that among them produce 98% of the world's most cited 1% of papers by field and year of publication.
The result showed a remarkably unequal scientific world. The top eight countries in terms of science citation rank produced nearly 85% of the top most cited publications between 1993 and 2001, while the next nine produced 13%, he said.
"There is a stark disparity between the first and second divisions in the scientific impact of nations," wrote King. The contrast with the remainder of the world's 163 nations is even starker, and the political implications of this "are difficult to exaggerate," he added. South Africa is the only African nation in the top 31, and Iran the only Islamic country.
RTWT, as there are interesting indications that this is yet another case of the Anglosphere vs everybody else.
Jay Manifold [4:52 PM]
[ 20040714 ]
Had We But World Enough, And Time
Longevity Meme's founder, who assures me that Reason is a legal name and should not be enclosed in quotes, points to a posting about Ray Kurzweil's recent talk on NPR. This gives me a great excuse to render one of my favorite passages from one of the books on this list:
"The best thing for being sad," replied Merlyn, beginning to puff and blow, "is to learn something. That is the only thing that never fails. You may grow old and trembling in your anatomies, you may lie awake at night listening to the disorder of your veins, you may miss your only love, you may see the world about you devastated by evil lunatics, or know your honour trampled in the sewers of baser minds. There is only one thing for it then -- to learn. Learn why the world wags and what wags it. That is the only thing which the mind can never exhaust, never alienate, never be tortured by, never fear or distrust, and never dream of regretting. Learning is the thing for you. Look at what a lot of things there are to learn -- pure science, the only purity there is. You can learn astronomy in a lifetime, natural history in three, literature in six. And then, after you have exhausted a milliard lifetimes in biology and medicine and theocriticism and geography and history and economics -- why, you can start to make a cartwheel out of the appropriate wood, or spend fifty years learning to begin to learn to beat your adversary at fencing. After that you can start again on mathematics, until it is time to learn to plough."
T.H. White, The Once And Future King
Jay Manifold [12:48 PM]
[ 20040712 ]
Latest Guest Post on eTalkinghead
What if terrorists attack the Electoral College?
Jay Manifold [4:22 PM]
[ 20040711 ]
"There's Only One Space Station?!"
That was the telling question asked by a guest at Powell Observatory on Friday night. I'd gone down there to meet Bob Gent, current president of the Astronomical League, who was visiting KC to see the AL office and confer with Avila University, which will be hosting next year's ALCON.
In addition to Bob (and AL VP Terry Mann), a group had reserved the facility for the evening. Said group appeared to consist of a couple of dozen high-school seniors and one beleaguered chaperone, and there were only two regular on-duty people running the place, so new ASKC president Joe Wright and I helped field questions during the program, which was a PowerPoint deck about comets (probably the one called "Space Invaders" in the listing at the bottom of this page). By the end of the Q&A it was pretty dark, so we all trooped into the dome and looked at Jupiter through the 30", using a wide-field 2" eyepiece with a focal length of 40 mm that yields about 95x. Two rather bright Galilean moons, probably Io and Ganymede, above and to the right of the planet, and another that was obviously Callisto much farther away from it on the other side. North and South Equatorial Belts clearly visible with glimpses of finer detail. No filter, so contrast wasn't especially high and the planet mostly just looked white. Obviously oblate due to rapid rotation and mainly-liquid composition.
Then there was time for standing around outside the dome and pointing things out in the sky. The kids were well-mannered and sharp-eyed -- they spotted a couple of satellites before I did -- and seemed geniuinely interested. I borrowed a really cool blue-green laser pointer from Joe and did the standard summer-sky galactography lesson: Summer Triangle, Cygnus Rift, we're moving towards Vega, center of the galaxy is over there in Sagittarius, north galactic pole is back overhead -- and got to point out a fine ISS pass; the station went almost directly overhead around 10:15 PM, appearing low in the southwest and disappearing low in the ENE several minutes later. Looked like about magnitude -2, as bright as Jupiter.
That's when I got the "there's only one space station" question. Keeping in mind that this was obviously an intelligent, affluent group in a generation that is widely expected to enjoy the benefits of space travel, and that the past eighteen months have witnessed a veritable barrage of space-related stories in the news: Columbia, the CAIB report, the Mars opposition, the Beagle, Spirit, and Opportunity landings, the Bush space proposal, the flight of SpaceShipOne, and now Cassini -- there are some pretty basic realities that just haven't penetrated the public's awareness. And the fact that thirty-five years after Apollo 11, exactly two human beings are in space right now, in one vehicle, is one of them.
Jay Manifold [7:40 PM]
[ 20040707 ]
Trivialities and Transcendence
-- is the title of my latest guest post over on Chicago Boyz. Enjoy!
Jay Manifold [7:30 PM]
[ 20040705 ]
I've quoted this before, but I don't care:
"You were saying, what is a nation? And who does more for a nation -- the one who makes a fuss about it or the one who, without thinking about it, raises it to universality by the beauty and greatness of his actions, and gives it fame and immortality? Well, the answer is obvious ....
"When the Gospel says that in the Kingdom of God there are neither Jews nor Gentiles, does it merely mean that all are equal in the sight of God? No -- the Gospel wasn't needed for that -- the Greek philosophers, the Roman moralists, and the Hebrew prophets had known this long before. But it said: In that new way of living and new form of society, which is born of the heart, and which is called the Kingdom of Heaven, there are no nations, there are only individuals."
Boris Pasternak, Dr Zhivago
Jay Manifold [7:14 PM]
[ 20040704 ]
America Has Something to Offend Everyone
And so do I, in my latest post over on Chicago Boyz.
Jay Manifold [6:52 AM]
[ 20040702 ]
Saturnian Memories and Future Hope
This astonishing, ethereal image of Saturn's F ring, transmitted to Earth from Cassini yesterday morning and shown at yesterday afternoon's news briefing, captures the empyreal nature of the Saturnian system as well as any photograph yet returned by the probe. Even as seen from Earth, Saturn is literally breathtaking; this picture approximates its appearance in a large telescope under ideal conditions (stand about four feet from your monitor to get an idea of the planet's apparent size at 300x). The sense, as in the Clarke quote below, is overwhelmingly one of a fantastically intricate and delicate artifact.
Every amateur astronomer remembers that first glimpse; mine was around 6:30 in the morning of Sunday, September 12, 1976, through my first real telescope -- like that of many another amateur in the '70s, a Criterion RV-6 Dynascope® -- and is inextricably intertwined with other sensory impressions: the smell of the bakelite tube, the faint whir of the drive motor, the metallic chill of the steel and aluminum mount, the cool dampness of a Midwestern morning when the heat of summer has passed but it is not yet autumn. And thanks to this wonderful application, I can even reproduce the sky as it was then. Jupiter near the zenith, Orion high in the south ... yes, I remember the light from the waning gibbous Moon, washing across the white, finely ground gravel of the driveway behind the duplex. Saturn thirty degrees above the eastern horizon, just above the glow of morning twilight. My father was an early riser, as I am now, and after sufficiently recovering from the stunning sight of the rings, I went in and got him. He gasped, as would hundreds of others over the decades when looking through a telescope I had set up, and immediately muttered something about how my mother should see this.
Which is the other great common experience of every amateur astronomer -- seeing the guest catch their breath and act on what is invariably their first impulse: to share the view with someone else.
Saturn's F ring is, at most, 500 kilometers across; to see it in a small telescope as Cassini saw it yesterday, one would have to be within a few million kilometers, no further from Saturn than its outermost regular satellite, Iapetus. Can there be any doubt that some distant descendent of the X-Prize competitors will offer high-inclination cruises above the plane of the rings?
UPDATE: Will Collier reminds us that this is what anti-nuclear protesters tried to abort.
Jay Manifold [7:40 PM]
California and Photovoltaics (II)
Previously unknown reader (the best kind) Edward Hahn wrote in to comment on my critique of the California photovoltaic regulation. I'm as lazy as the next blogger, and certainly no more knowledgeable, so he has the floor:
I'm a California native, a southern California homeowner, and someone who has helped install a PV system on a friend's house several years ago. Working through their numbers, and watching the birthing pains was enough to keep me from installing such a system myself.
But...
Virginia Postrel writes on the cost of solar energy, and the regulatory impulse. It might be pointed out that the state already regulates, in excruciating detail, passive methods that have to be taken.
At some point the diminishing returns and increasing costs of super-insulation techniques will meet and exceed the decreasing costs and increasing benefits of active PV systems. I don't claim that the crossing is today, but doubt that it is more than 10 years away.
From the standpoint of the electric grid the integrated effect of a very well insulated house and a moderately insulated house with a PV system would be about the same. But the non-integrated effect of a PV home, with the panels properly oriented, means that it would be producing power at exactly the time it is needed, late afternoons in summer.
The cost of the system, estimated at $20,000 by its opponents, is a relatively small amount when compared to the median housing prices used in one of Postrel's own articles last week, Housing Bubble.
It should be mentioned that this cost is heavily subsidized with tax breaks and rebates - 50% of that stated cost would be a fair estimate of the cost savings to my friends.
Tabulated, using her home costs, PV costs from PV opponents, and my own estimated subsidies, we get:
2004 Median Home Price | Cost Increase Due To Mandated PV System | Cost Increase After 50% Subsidies |
Los Angeles - $399,000 | 5%, to $419,000 | 2.5%, to $409,000 |
San Francisco - $606,000 | 3.3%, to $626,000 | 1.65%, to $616,000 |
I'm not an economist, and my engineering econ classes are but misty memories, but these numbers wouldn't seem to be deal breakers for homebuilders or buyers.
Given that the price of PV panels seems to be decreasing at about 10% a year, somewhat tracked by costs of inverters and such, and that labor prices continue to rise, a better use of the state's regulatory impulses might be to lay groundwork for economical systems in the near-to-mid future. Mandate, rather, that a second electrical box be installed, with full disconnect switch and associated wiring so that future off-the-shelf cost efficient PV systems be easily added to homes.
That the PV industry supports the proposal is not surprising. It's in their best interest. One could easily find opponents - perhaps traders in electrical and natural gas markets, that oppose it, understandably because it is again in their own best interest.
The question is (or should be): what is in the best interest of the individual homeowner and California as a whole?
Now for my comments, which I have deliberately avoided interleaving with the above, lest this look like a fisking:
- It is technically correct that the additional regulatory and financial burden is marginal. I would point out, however, that as Virginia herself has ably argued, margins matter (look for the paragraph beginning: "Besides being easy to read, it's cheap ..."), even small ones in the price of books.
- I concur that cheap PV systems can't be much more than a decade away. Drexler has suggested that someday we'll pave roads with the stuff.
- I also concur that PV systems in Southern California will produce power when it is most needed. But the farther north you go, the less true this becomes, at least outside of the Central Valley; thus my suggestion that if a regulation is inevitable, it be applied by county.
- Four to six hundred grand for a house? Are you people nuts?! ;)
- Mandating a second electrical box would indeed be far less burdensome and would hasten the transition once PV becomes a relatively minor expense. The question then becomes whether hastening this transition is a high enough priority to justify this kind of intervention.
Ultimately, we get back to that boring old libertarian argument that it's best to just let people make up their own minds. I incline strongly to this view. The only thing I see countering it is a possible neighborhood-effect argument whereby the power grid becomes more stable and secure as peak loads are handled by PV panels. Did the sponsoring legislators raise this point?
UPDATE: Well, I didn't get an answer to that one yet, but previously unknown reader (the best kind) Bruce Ross, who judging by his e-mail address is from the northern end of the Central Valley, writes: "For what it's worth, the photovoltaic bill exempts the northern coastal areas as well as large parts of the Sierra Nevada. The fools who govern Calif. prefer not one-size-fits-all rules, which at least have the virtue of simplicity, but regulations so dense with loopholes, exemptions and codicils and amendments that they resemble nothing so much as the federal tax code."
This raises a further issue, namely the tradeoff between simplicity/predictability on the one hand and local suitability on the other. Another reason for such regulations to be imposed at the county or municipal level, if they are to be enacted at all. Just to reinforce the point, see this remarkable illustration of California's geographic diversity (part of this wonderful atlas).
Jay Manifold [7:36 PM]
[ 20040701 ]
-- per NASA TV, first images to become available around 7:25 AM CDT.
UPDATE (7:30 AM CDT) - First image, apparently of the C ring (sometimes called the crepe ring), a diaphanous, diagonal stripe across the right side of the picture. Artifacts (horizontal bands) and cosmic-ray effects ("stars") not yet edited out of raw image.
(7:47 AM CDT) - "Best image so far" shows possible "density wave" in rings -- diagonal (due to orientation of image) bands of varying thickness, separated by narrow gaps, all produced by the gravitational effects of shepherding satellites.
(8:01 AM CDT) - Cassini is now the 2nd lead story on CNN Headline News. At least one of the latest images is of the eponymous Cassini Division, which notwithstanding its appearance from Earth does contain some ring material. Carolyn Porco stated that the smallest details in the images are ~400 km wide. I note that all this was predicted:
But the glory of the rings continually drew Bowman's eye away from the planet; in their complexity of detail, and delicacy of shading, they were a universe in themselves. In addition to the great main gap between the inner and outer rings, there were at least fifty other subdivisions or boundaries, where there were distinct changes in the brightness of the planet's gigantic halo. It was as if Saturn was surrounded by scores of concentric hoops, all touching each other, all so flat that they might have been cut from the thinnest possible paper. The system of the rings looked like some delicate work of art, or a fragile toy to be admired but never touched ....
Sometimes a star would drift behind the rings, losing only a little of its brilliancy as it did so. It would continue to shine through their translucent material -- though often it would twinkle slightly as some larger fragment of orbiting debris eclipsed it. (p 176)
(10:45 AM CDT) - Sample image here.
Jay Manifold [5:52 AM]
