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"A Half-Century of Comets"
I've been interested in astronomy for a very long time, really most of my life. And the first "comet" I became very interested in wasn't a comet at all; it was a meteor storm left behind from a long-ago comet.
In early 1966, I became aware of the "predictable" Leonid meteor storm. Unlike the standard run-of-the-mill garden-variety meteor shower, this one was predicted to spew upwards of thousands of visible meteors per hour.
A meteor storm, as differentiated from sporadic meteors (the Earth running into celestial debris in its orbit, usually at the rate of about 4-7 naked-eye meteors per hour) or meteor showers (wherein the Earth encounters a thickened debris field left behind by any number of wayfaring comets, often exuding 20-60 naked-eye meteors per hour) -- a meteor storm is characterized by the Earth's rendezvous with thousands of naked-eye meteors per hour. The reason for this is simple -- the three-dimensional debris fields of comets possess thicker and thinner areas, hence the vast differential in meteor encounters.
So, inpatient boy that I was, I prepared and expected to view this explosion of meteors in the early morning hours of November 18, 1966. All set up (with a camera even then) ready for the event, predicted to peak just before dawn. But alas, it was utterly cloudy (as it almost always is in November on the east coast), and no meteors (or stars, even) were seen. However, on the west coast and in the Rocky Mountain West, those lucky witnesses viewed thousands of meteors per hour.
An article in Sky and Telescope Magazine noted the following:
"Perhaps the best views were from California and Arizona. At the Table Mountain Observatory, near Wrightwood, Calif., one resident astronomer commented that he and a colleague, '... watched a rain of meteors, turn into a hail of meteors and finally a storm of meteors, too numerous to count by 3:50 A.M. Pacific Time. Instinctively, we sought to shield our upturned faces from imagined celestial debris.'
From 6,850-foot Kitt Peak in southern Arizona, thirteen amateur astronomers were trying to guess how many could be seen by a sweep of their heads in one second. The consensus of the group was that the peak occurred at 4:54 A.M. Mountain Time, when the staggering rate of 40 per second (144,000 per hour) was reached!" –- from https://www.space.com/3096-shooting-star-reflections-leonid-meteor-storm-1966.html
Luckily this phenomenon has been studied extensively both long before and after the 1966 event. It turns out that this phenomenon happens every 33-35 years as the Earth passes through the dense debris field of Comet 55P/Tempel-Tuttle. Not surprisingly, the debris field is not-at-all consistent -- that is, in some years (new estimates suggest every 133 years or so, as in 1966), the resultant debris field is the absolute densest. Those European drawings of an impressive (actually frightening) meteor storm in the 1800s are of the debris left behind by Comet Tempel-Tuttle. Alternatively, this comet has an orbital period of ~33 years, with wide variation in its resultant debris field.
On the morning of November 18, 2001, I photographed this meteor storm from a location in South Park, CO. Here is part of what I wrote in the 2002 Christmas card and the book Ghosts of Christmas Past:
From the beginning, we became immediately aware that it was to be a noteworthy morning. In the first hour, we observed at least one meteor every 15-30 seconds. At the maximum, we saw an astounding 50 meteors per minute, almost one per second. Most were 2nd to 4th magnitude (the brightness of the stars in the Big / Little Dippers), but some were very bright bolides (much more brilliant than Jupiter!), leaving dust trails lingering for sometimes well over 2 minutes.
This maximum lasted only about 20 minutes, from about 03:10 to 03:30 A.M. MST (10:10 to 10:30 UT). These times correspond very favorably to the models presented in the November 2001 issue of Sky and Telescope and Astronomy magazines. Our observed maximum and times were very close to the predictions of Esko Lyytinen and Tom Van Flandern of Meta Research in Washington, D.C.
Although there were great comets in the 1960s, some even visible from my parents' home on the east coast, the first actual comet I observed (and photographed) was the well-known-supposed-dud Comet Kohoutek, in January 1974 from the then deserted Genesee Park, CO. This close-in Front Range location was uninhabited and utterly undeveloped in 1974 -- I set up a film camera on an electric "drive" (to mimic/nullify the Earth's rotation). My companion and I were alone in the large park and enjoyed an unobstructed view to the western horizon. I would strongly suggest that taking notes is imperative if you decide to embrace this sort of astronomical endeavor.
In the passing years, I did not view or photograph any comets. This anomaly was due in part because I was busy starting a family and also because there was an absence of comets visible from the northern hemisphere. Comet West, appearing in February/March of 1976, was an exception. Unfortunately, for reasons long-forgotten, I did not experience this spectacular comet, often referred to as "showstopper." Comets are commonly rated by experienced comet-watchers –- West is always near the top of many lists, as are Hyakutake and Hale-Bopp, two comets of which I have seen and photographed.
Halley's Comet (discovered in 1758 by Edmund Halley and pronounced "HAL-eeees" like the computer in 2001 – A Space Odyssey, not "hail-eeees" like the precipitation) came around with much brouhaha in 1986, promising to equal its performance in 1910, as described in Sky and Telescope Magazine . . .
"Halley's May 6–27, 1910 After perihelion, it evolved into an increasingly large and imposing object in the eastern morning sky. On the morning of May 19th, after the Moon had set, the tail was seen to stretch for 120° — two-thirds of the way across the sky!" -– from https://skyandtelescope.org/uncategorized/the-greatest-comets-of-the-past-century/
One wonders as to the accuracy of this description. Still, indeed the comet did impose "fear and loathing" on London's good citizens, which at the time did not have any artificial light; that paucity contributing to the visibility of the otherwise amorphous tail of the comet. I do not doubt that it was a spectacular object.
Halley's Comet became visible again in March of 1986. A buddy of mine, his wife, and my wife and kids traveled to Big Bend National Park to get a better view. Unfortunately, there were brush wildfires in adjacent Mexico, so the observing wasn't all that great. We did, however, have a great side trip across the Rio Grande astride of donkeys and onward to the remote village of Boquillas, MX. As I wrote in Ghosts of Christmas Past:
Later, while disappointingly traveling northward and home, we did get a great view from Carlsbad Caverns National Park, New Mexico (actually, we observed the comet above-ground from Carlsbad’s mirror park, Guadalupe National Park; that location sporting some of the darkest skies I've ever encountered). From there, we visually observed the comet in all of its grandeur, it exhibiting a spectacularly bright tail.
After returning, I decided that perhaps I ought to photograph the comet, having spent a fair bit of my life previously observing astronomical subjects and occasionally photographing them. I set up on our second-story deck in Conifer, Colorado in March of 1986 and obtained some adequate time exposed shots of Halley's Comet, using my telescope/mount as a makeshift tripod.
The resultant final image became the first family Christmas card.
A full ten years later, another most spectacular comet (some characterize it as the twentieth century's best comet!) appeared. And if it wasn't for a workmate of mine, who called the clueless me asking how he should observe it, I may have missed it altogether. Luckily, due to his "warning," I didn't. Here's how Sky and Telescope Magazine describes Comet Hyakutake:
"Hyakutake March 19–April 4, 1996 It came to within 0.1018 a.u. of Earth on March 25th, the intrinsically brightest comet to pass so close to Earth since 1556. It could be observed almost directly overhead during the predawn hours, shining as bright as zero magnitude and against a dark sky sporting a tail that approached 100° in length. John Bortle calls it 'One of the grandest comets of the millennium!'" -– from https://skyandtelescope.org/uncategorized/the-greatest-comets-of-the-past-century/
Comet Hyakutake was undoubtedly one of the most significant comets of my lifetime; some rank it as one of the most visually impressive comet visitations ever. This object was so bright that my wife and I could see it while driving around through the brightly lit Conifer, Colorado Safeway parking lot at night. And it stretched, at maximum, approximately a remarkable 90 degrees (one-half the width of the visible sky). I furiously wrote notes and created crude drawings of the celestial visitor over several days of optimum viewing. Of course, its somewhat less than month-long visit allowed ample photographic opportunities as well. I took many rolls of film, generally employing a physically-altered hyper-sensitized Kodak copy film.
As one observed the comet during the late weeks of March, watchful bystanders could perceive the comet's ever-changing motion as it circled the sun. Cometary tails "point" away from the powerful gravity of the sun, so as they orbit around it (Hyakutake was a sun-grazing comet) comets pivot on their axes. Observers ascertained this movement night-to-night.
Not much more than a year later (quite an uncommon occurrence), the spectacular and widely predicted Comet Hale-Bopp graced our skies. It had been co-discovered two years previously by Americans Alan Hale and Thomas Bopp. Sky and Telescope described it as follows:
"Hale-Bopp Feb. 15–May 15, 1997 Visible with the unaided eye from July 1996 thru Oct. 1997, an all-time record. From Mar. 5th to Apr. 5th, it could be observed both in the northeast sky at dawn and the northwest sky at dusk. Perihelion was Apr. 1st and during the next couple of weeks evening skywatchers could see a prominent dust tail and a fainter gas tail, each 15 to 20° long. According to a survey by Maricopa Research, the comet was seen by 81% of American adults; more than the Super Bowl." -– from https://skyandtelescope.org/uncategorized/the-greatest-comets-of-the-past-century/
From our residence in Conifer, Colorado, Comet Hale-Bopp graced our western sky for hours after sunset, providing adequate time to get a great photograph. Comet Hale-Bopp was particularly photogenic; its location in the sky among Milky Way star fields and its magnificent blue ion tail (seen and photographed in late March 1997) were beautiful highlights of this remarkable object.
Again, many years passed. According to various lists, the Earth wasn't blessed with many comets during that period. Understand that every year the Earth does intersect cometary paths, and every year multiple comets ARE discovered (or rediscovered, as is sometimes the case, i.e., Halley's Comet). Most are visually unremarkable.
During that period, something miraculous DID take place -- that being the almost complete replacement of film photography with digital photography. In the realm of more advanced astronomical research, the digital approach had been employed for some time, but during the more recent period noted, this process became normalized and popularized. I resisted the change from film to digital for a while but eventually embraced it. The last three comets discussed here were photographed digitally.
Comet Pan-STARRS was the first of this group. According to Sky and Telescope, this lowly comet is ranked down in the "garden-variety-comets" category. Nevertheless, we viewed and photographed it from our rural property near Taos, NM.
"Pan-STARRS Mar. 4–16, 2013 Difficult for many to see due to a combination of strong evening twilight while also remaining very low to the western horizon. Visually, very disappointing. "Rarely is such a bright comet so hard to see." – from https://skyandtelescope.org/uncategorized/the-greatest-comets-of-the-past-century/
I took the shot from a fixed tripod and sent the digital file to the local newspaper, which, to my surprise, published it.
In January 2015, we celebrated "first light" (grand opening) of my permanent Rabbit Valley Observatory. Our dogs and I attended the gala event! Virtually the second object I photographed from a sophisticated equatorial tracking platform and magnified through a fine refracting telescope was Comet Lovejoy.
Frankly, upon seeing the comet come up on my computer screen (astrophotography of this type is highly computer and software-centric), I was stunned. Such a beautiful and detailed image, and so green! For the final image, I combined five shots and did the post-processing in Photoshop. What is great about this sort of photography is that the photographer can immediately assess the acquired image's quality. The creator doesn't have to depend AT ALL on a darkroom technician. Instead, you (the photographer) process the photo from start to finish –- essentially doing all the "darkroom" work yourself -- and then send the digital file off for printing, if desired. I always check the "do not alter or manipulate the image in any way" checkbox. WYSIWYG. Really!
There have been several Comet Lovejoys –- the comet-hunting discoverer is Australian astronomer Terry Lovejoy, who discovered this object on August 17, 2014.
Finally, this year (2020), the magnificent Comet NEOWISE appeared, first in the morning sky and then later in the northwest evening sky. I wrote copious notes on the observing and photographic process –- these can be accessed at my taosastronomer.com website. I'd rate this comet right up there with Hale-Bopp and even Hyakutake. It was extraordinary to see (with the naked eye) the comet rising above our spectacular Sangre de Cristo mountain range east of town, and then later in July witness it (easily seen and photographed with caveats noted) in the Big Dipper of the evening sky. Displaying an elegant, gently curving dust tail and a subtle yet beautiful blue ion tail, Comet NEOWISE was a remarkable object!
"Comets have this peculiar duality whereby they first brought the building blocks of life to Earth some 3.8 billion years ago, and subsequent cometary collisions may have wiped out many of the developing life forms, allowing only the most adaptable species to evolve further. It now seems likely that a comet or asteroid struck near the Yucatan peninsula in Mexico some 65 million years ago and caused a massive extinction of more than 75% of the Earth's living organisms, including the dinosaurs. At the time, the mammals were small burrowing creatures that seemed to survive the catastrophic impact without too much difficulty. Because many of their larger competitors were destroyed, these mammals flourished. Since we humans evolved from these primitive mammals, we may owe our current preeminence atop Earth's food chain to collisions of comets and asteroids with the Earth." -– from https://cneos.jpl.nasa.gov/about/life_on_earth.html
It's no wonder; then, when experiencing a comet, you get the feeling that you may never again witness something as ethereal and exquisite. In essence, that realization, along with an understanding of what role comets have likely played in the development of life across our solar system –- that astute and sanguine realization embodies and defines the profound and special magic of comets. Comets are unique, unpredictable visitors. They are rare and unexpected gifts from the heavens, as they may very well have been since even before the dawn of life on Earth. And I have personally been blessed to view and even photograph quite a few of them over (almost) a full half-century!
(Click this text to access the photographic and historical details of the discussed comets.)
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