-- was my first solar eclipse. I watched it from here, more or less; I think we were about 2 miles east of Ft Peck itself, in a public access area near the east end of the dam. "We" were half a dozen fortunate members of the University of Chicago undergraduate astronomy club, plus one high-school student, and had made the trip to Montana in the Yerkes Observatory van. I will spare my readers (on this occasion, at any rate) the flood of memories this invokes for me, and mention only a few aspects of the experience I have not seen closely described elsewhere (but see this thorough account).
The pictures, fine as they are, do not convey either the sense of immersion or the utter immediacy of totality; it is a three-hundred-sixty degree, three-dimensional, wraparound phenomenon, of which the eclipsed Sun is only a tiny, if dazzling, component. So while the corona covers a few square degrees of sky, the remaining forty-thousand-plus square degrees of one's personal celestial sphere are all transformed into a scene of utmost rarity and seeming transcendence, one that occurs at any given spot on Earth only once every several centuries. We accordingly lack a vocabulary to describe it properly, "we" now being the one in ten thousand of all the humans that have ever lived who has witnessed a total solar eclipse. I have seen two and hope for several more, and am thereby all the more grateful for living in this time and place.
Our original planned destination was Brandon, Manitoba, but we turned aside into Montana on the faint hope of slightly better weather (I later heard that had we attempted to cross into Canada with a vanload of optics, we would have been assessed thousands of dollars in some kind of import tariff, which we would have been entirely unable to pay). The random likelihood that the skies would be clear in that part of the country on the appointed date was only 19%.
We needn't have worried; the weather was flawless, not only almost perfectly clear but surprisingly warm, which is to say that it actually got above freezing later in the day, after the eclipse. So instead of a frustrating drive across a frozen wasteland in search of a hole in the clouds, we stood in the shadow of the Moon for one minute and fifty seconds.
Or, in my case, jumped up and down shrieking like a teenybopper at a concert, with the occasional peek through one of the telescopes, or the binocs I'd brought. Hey, I was nineteen. But never again will I think it contemptible that primitive peoples react to these things with terror. In the final moments before second contact, the umbra became visible in the west-southwest, and grew to a wall of darkness, towering into the sky and reaching from horizon to horizon, moving toward us at two thousand miles an hour. I knew exactly what was going on, and simultaneously felt a fear unlike any other; fear of something at once utterly unfamiliar, overwhelmingly menacing, and hopelessly unstoppable. Do not wonder that armies have made peace in such circumstances.
During totality itself, there are at least three phenomena which photographs do not, and perhaps cannot, transmit: the twilit horizon, as though the Sun had set in all directions at once; the sudden and complete revelation of the inner Solar System, with Mercury and Venus high in the sky, one on each side of the Sun -- and, in this case, Mars as well, on the same side as Venus but closer; and the pure, actinic hue of the corona, a multi-million degree gas far thinner than Earth's atmosphere, shining with a light that might have been designed to reinforce the ancient (and false) dichotomy between the terrestrial and the celestial. There is truly nothing like it on Earth.
The indispensable Fred Espenak is the go-to guy on these things, and grazing through his info reveals that the next opportunity (after the one next month, that is) is on 2009 Jul 22 in China and the western Pacific, followed by 2012 Nov 13 in the south Pacific. So start saving those nickels and dimes! (Around here, we're waiting for 2017 Aug 21 and 2024 Apr 8.)
One of the few results of this search that rises above the mediocre is titled What A Real Peace Rally Looks Like. Well, it's that time of year again, and I'm already booked Monday evening, so I thought I'd help announce it here by way of making up for my non-appearance. Locals feeling motivated to participate are urged to graze on over to The Gathering for details.
On the other hand, I do plan to make it to the Michio Kaku lecture on Tue 7 Mar.
Inveterate Arcturus readers will recall my earlier mention of Kaku and subsequent follow-ups:
Perhaps not the most original name -- it beat out, among others, the considerably more poetic and logo-friendly Marais des Cygnes -- but in any case, it's on for Thursday-Sunday 22-25 June. Registration form at the ASKC Dark Sky Site page.
(Ref Space, Twenty Years On for background on GRB detection.)
NASA Detects 'Totally New' Mystery Explosion Nearby, blares the headline of Robert Roy Britt's story. "Nearby" is relative -- it's 440 million light-years away, or about 200 times as distant as the other large members of the Local Group of galaxies -- but the article implies that the optical component of the explosion, or whatever it is, may well be visible to dedicated amateur astronomers.
Best of all, Britt provides the coordinates (RA: 03:21:39.71, Dec: +16:52:02.6). So, grazing over to the Hawaiian Astronomical Society's Aries page and looking at the wide-area map, we find it to be near the border with Taurus, forming a slightly squashed isosceles triangle with the Pleiades and the Hyades.
Grazing onward to YourSky, and creating the appropriate map, we find that as seen from mid-northern latitudes, this spot will be nearly at the zenith at sunset tonight, and high in the western sky throughout early evening.
Googling "GRB 060218" turns up this bulletin, which suggests that the event is around magnitude +18. At the stated distance, notwithstanding that as near as I can tell, this works out to around half a billion solar luminosities, it would require a telescope more than a meter in aperture to detect; but CCD imaging is far more sensitive than the human eye, and should bring it within the range of large amateur instruments. Go get it!
Graze on over to SpaceWeather.com, and -- perhaps after taking a moment to notice that the Sun is almost entirely quiescent at the moment -- select February 18, 2006 under "View archives" on the right-hand sidebar, then scroll down to "Double Rainbow."
There's much, much more where that came from; after being properly showered with compliments on our Yahoo! group, the ASKC's own Dan Bush, who IMHO is shaping up to be one of the premier photographers in amateur astronomy anywhere, kindly pointed us to a sumptuous pageful of images, February 2, 2006 Rainbow at Elam Bend (McFall, Missouri), complete with quote from Wordsworth.
For previous instances of rainbowblogging on Arcturus, see:
Graze on over to ObservingSites.com for a handy directory. Thanks to Joe Wright of the ASKC for the tip. One site that's not on the list yet, but should be soon, is here (be aware that it is for ASKC members and their guests only).
Posting in the ASKC E-Group, David Baker passes along a little-known fact: "When the space shuttle was first put into service, someone suggested loading the cargo bay with cattle in order to test the freight-hauling capacity. It would have been the herd shot 'round the world."
| You scored as Babylon 5 (Babylon 5). The universe is erupting into war and your government picks the wrong side. How much worse could things get? It doesn't matter, because no matter what you have your friends and you'll do the right thing. In the end that will be all that matters. Now if only the Psi Cops would leave you alone.|
Your Ultimate Sci-Fi Profile II: which sci-fi crew would you best fit in? (pics)
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Over on the ASKC E-Group, George Allen tells it like it is:
Rural deputies don't usually have a positive first impression of city guys hanging around in the dark, near the woods, moving large tubes that appear to be mortars or cannon, flashing red lights around, talking in Latin and Arabic and listening to radios that go "beep, beep, beep."
I shudder to think that a game warden would get a tip about poachers and take up a surveillance in the woods, and see green lasers in the sky, crawls nearer to find a dozen red lights moving about in the dark, hears someone say, "From Canes Venatici go north to Alioth/Megrez, splitting the distance to Mizar." This being followed by the whirrr of GOTO motors causing the rocket launcher to swing slowly toward the warden.
The one good thing about getting the cops called on you -- and it's happened to me dozens of times, including the very last time I was out observing -- is that you can show them exactly what you're doing, and they'll not only understand but enjoy the experience. For a couple of years in the '90s, I had what amounted to a steady working relationship with sheriff's deputies in Stephens County, TX, where my (slightly informal) observing site was located. After the first time they showed up, I explained that I'd be out there on clear weekend nights nearest New Moon, and they'd drop in, cutting their headlights, and let me look through their night-vision 'scopes.
In late January of '87, on the first anniversary of the Challenger disaster, I saw Koyaanisqatsi -- which ends with the explosion of an Atlas-Centaur (perhaps the one carrying Mariner 8), endlessly replayed in slow motion; and followed it up with the ASKC meeting, at which the speaker was Kent Cavanaugh, one of Missouri's two participants in the Teacher in Space program. He had trained with Christa McAuliffe, and his talk, while excellent, was also easily the most depressing one I've ever heard at any meeting of an astronomy club, necessarily including as it did a deeply personal reminiscence impinging on a tragic event.
So I'm happy to report that for the twentieth anniversary, I both avoided seeing a movie with an ambiguous ending and heard not one but two decidedly upbeat talks, again courtesy of the ASKC. First up was Neta Apple, recent arrival from Tulsa, who now lives somewhere near Adrian and attended the AAVSO convention last March on a NASA E/PO grant, in return for which she is obligated to give talks about the Swift GRB Explorer.
The topic of gamma-ray bursts turns up occasionally on Arcturus -- see, for example, Ordovician Extinction Caused by GRB?, and Mass Extinction Dodged -- and may be intimately related to the Fermi Paradox. Neta passed along the notion that the P-T extinction (a/k/a "the Great Dying") may have been the result of a "grazing" GRB (but see The Greatest Disaster of All for an alternative explanation).
She also noted that they were discovered by the Vela satellites, which of course were looking for g-rays from an altogether different source; I note that at the same time, other spysats looking for bright flashes of light were also inadvertently discovering lots of incoming meteoroids, as discussed in A Modest Proposal for an Asteroid Warning System. Perhaps yet another argument in favor of my (initial) proposal to replace the Hubble? But I digress ...
GRBs emit ~1052 ergs in a couple of seconds; "short" bursts, <2 sec, are caused by merging neutron stars, while "long" bursts, >2 sec, are from hypernovae. This is 10x the Sun's lifetime output (which I calculate to [briefly] represent a luminosity of ~1017 LSun), and would be sufficient to vaporize Earth -- 100 billion times. "Not good neighbors," as Neta put it.
Of course, it occurs to me that it'd be great if we could see one close enough to get a good look at it without getting fried. So assuming we don't want it to exceed the apparent brightness of the Sun, and applying the inverse-square law, it would need to be at least 400 million AU distant, or a little over 6,000 light-years. The Swift spacecraft itself -- for once, not an acronym; rather, it was named for its ability to relatively quickly repoint itself to take images of GRBs as soon as possible after they occur -- detected one of the largest GRBs after only 3 weeks in orbit. Anyway, thanks are due to Prof Lynn Cominsky and her team at Sonoma State U for their education and public outreach work on this project.
On to the Weaubleau Structure (previously mentioned in Crater Critter Community Council Creates Confab and Crater Critter Community Council Confab Communiqué) ... and a lesson in Missourian pronunciation: a native American name, transliterated into French and inherited by us, now sounds like "WAH-blow." (I happen to have already known this, largely because my parents lived near Hermitage, MO, from the mid-'80s to the early '90s.) The speaker was Kevin Evans of Missouri State University (formerly SMSU), Springfield.
The structure was first identified by Beveridge around the middle of the last century; in the mid-'60s, Snyder and Gerdemann classified it among the 38th parallel structures, and in '95, in the wake of the Shoemaker-Levy 9 impact on Jupiter, Rampino and Volk suggested a "serial impact origin," a string of meteoroids from a parent body hitting in a line across what is now Kansas, Missouri, and Illinois. Evans stated that not all the 38th parallel structures are the result of impacts -- but some are, and it is now nearly certain that Weaubleau is one.
He told us that the University of New Brunswick maintains the Earth Impact Database, which currently lists 172 known impacts. Weaubleau is not yet on the list, but someday it will be; the evidence from shocked quartz, planar deformational features, and perhaps 300 meters of stratigraphic uplift will see to that.
The meteoroid hit 340 million years ago (±5 million), in a shallow sea -- the area was a continental shelf -- and tsunamis sloshed back and forth afterward, leaving alternating layers of coarse and fine-grained material. The stratigraphic column in the area is a jumble; contra a ridiculous YEC urban legend, this is rare, and in fact is powerful evidence of an impact.
And if you'd like to see it for yourself, there's a field trip coming up! The ASKC's David Neuenschwander posted this on our Yahoo! Group:
Dr. Evans will lead another field trip through the Weaubleau-Osceola Structure on Presidents' Day, Monday, February 20, 2006. The field trip is for undergraduate students at Missouri State University but the public is invited to attend.
They will leave Springfield at 8:00 a.m. and plan on meeting at the MoDOT garage at Highway 13 & 82 junction at Osceola around 9:00. The tour will last until lunchtime. See you there!
If you go, please wear a hard hat and boots; and here's a map link.