LtE in CMO #269

From William SHEEHAN

. . . . . . . . . . Apologies for not being in touch the last week and a half or so -- I have been away (at Yerkes Observatory, where I was doing research on a history of the study of the structure and evolution of the Galaxy, particularly by focusing on the work of W. W. Morgan the spectroscopist and discoverer of the spiral-arm structure of the Milky Way).


I have returned, however, and just today sent out to you the first edition of Percival Lowell's *Noto*. It is sent with my sincere best wishes for your enjoyment of it, also in expectation of our successful explorations of the peninsula next year!

With my warmest regards,

(3 February 2003 email)


. . . . . . . . . .Subject: more on Martian dust storms


Dear Masatsugu,


Here's an interesting data set that may be of some use. I pulled it down when I was searching for other NOAA information. It goes way back but may be of interest in looking at even more remote aspects of the Martian data set.


Note that this researcher found evidence of the Little Ice Age dating through 1920, then a present warm stage that began then. It may be significant in view of the fact that your historical search of the Martian dust storm literature reveals no planet-encircling or global events before 1909 and 1924. I know that part of Sallie Baliunas's argument about the solar contribution to global warming on Earth is that the largest part of the warming in the 20th century took place prior to the increase of carbon dioxide owing to human emissions.

Meanwhile, I'll keep looking,

(9 February 2003 email)

(Note) The attached article is Temperature Variation in China During the Last Two Millennia (World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program)


. . . . . . . . . .Dear Masatsugu, I do hope the book brings you pleasure.

I am pressed for the time at the moment, so will be brief, but will respond more fully soon.

With my very best wishes,

(12 February 2003 email)


. . . . . . . . . . In the event you might be interested, an article I just wrote for the Astronomical Society of the Pacific's magazine, Mercury. You may use anything you like for your publications.

With very best regards,

(24 February 2003 email)

In late August 2003, Mars will be closer than it has been for a very long time. In the past, astronomers have savored Mars's close approaches, and have even gone to the ends of the Earth for good views of the mysterious Red Planet.


William Sheehan and Thomas A. Dobbins


This late summer, the faster-moving Earth will catch up with Mars as the two planets pursue their perennial paths around the Sun. At opposition on August 28, 2003 -Mars will, according to Jeff Beish of the Mars Section of the Lunar and Planetary Observers and Jim DeYoung of the U.S. Naval Observatory Time Service, approach within only 34,649,589 miles. That's slightly closer than it's been in 60,000 years. The last time it surpassed this record was during the Mousterian, when flaked hand-tools represented the most sophisticated technology humans possessed and Neandertals still shared Europe with Cro-Magnons.


Perihelic oppositions actually occur once every 15 or 17 years, whenever Mars lines up on Earth side of its orbit when it is also nearest its most sunward point, or perihelion. However, a collusion of factors, including slight changes over time in Mars's orbital eccentricity, will make the coming opposition the most favorable of our lifetimes.


Unfortunately for Northern Hemisphere observers, perihelic oppositions are always best seen from the Southern Hemisphere. The reason for this is that the perihelion of Mars's orbit lies in the direction of the constellation Aquarius. In 2003, Mars will lie 16 degrees south of the celestial equator, which means it will be far south, lurking in the mist near the horizon for observers even in the south of England, but overhead from Chile or Peru.




In the past, astronomers have traveled the globe in pursuit of the best conditions for observations of eclipses and transits of Venus. Mars's oppositions have also been the objects of a number of grand quests. At the September 5, 1877 opposition - when Mars at its closest was a few hundred thousand miles farther away than it will be this summer - David and Isobel Gill traveled to Ascension Island (10 degrees south of the equator) in order to obtain measures of the planet's positions relative to background stars.

They were seeking the precise value of the astronomical unit (the distance between the Earth and the Sun). Isobel charmingly described her first sight of the skies over Ascension:


"Sitting that first evening after sunset in the verandah ... we could speak of nothing, think of nothing, but the beauty of the heavens. Though Ascension was barren, desolate, formless, flowerless, yet with such a sky she could never be unlovely. The stars shone forth boldly, each like a living fire. Mars was yet behind Cross Hill, but Jupiter literally blazed in the intense blue sky now guiltless of cloud from horizon to zenith; and thrown across in graceful splendour, the Milky Way seemed like a great streaming veil woven of golden threads and sparkling with gems."


At the same opposition, Nathaniel Green, a professional artist who had given lessons to Queen Victoria, observed Mars from Madeira. He certainly enjoyed the climate; he may have enjoyed the famous wine. In any case, he captured the fine wine of that memorable opposition in one of the most aesthetically pleasing maps of the planet ever made.

{Illustration: Green's map of the planet}

And yet no two maps of the planet could have been more jarringly dissimilar than Green's Madeira map, made with a 13-inch Newtonian reflector, and another produced that same year by Giovanni Schiaparelli using the 8.6-inch Merz refractor at the Brera Observatory in Milan.

{Illustration: Schiaparelli's map of the planet. Dome and 8.6-inch Merz refractor at the Brera Observatory, Milan.}

A contemporary, Rev. T. W. Webb, called Green's map a "picture," Schiaparelli's a "plan." Personally, we prefer to think of them in terms of the two distinct styles of Japanese writing: Kanji, the picture or ideographic writing, versus Kana, the phonetic and combinative form. Green's map is Kanji, Schiaparelli's is Kana. They are right- and left-hemisphere views of Mars. In this particular case, it would be the left-hemisphere view - with the canals - that would cause all the trouble!


The next far-southerly perihelic opposition was in 1892, when William H. Pickering - the younger never-do-well brother of Harvard College Observatory's director Edward C. Pickering - found himself briefly in charge of Harvard's Southern Hemisphere Station at Arequipa, Peru. Perched at an elevation of 4,000 feet the foot of the towering, nearly-extinct volcano El-Misti, Arequipa was a Mars-observer's dream, even though the political situation in Peru was precarious at the time - there was a civil war in Chile, and Peru itself was lurching toward another revolution, leading one of the Harvard astronomers to quip that it might become necessary to remove the lenses of the telescopes and use the tubes as cannons! But the real disaster was William H. Pickering. He had no sense of the value of money, and quickly overdrew his account by building a large house complete with servant's quarter and a stable. He also ignored the stellar spectroscopy work that was his brother's priority in favor of making lunar and planetary observations. At least there is no denying that he was exceptionally keen-sighted, and he whetted the appetite of the Mars-crazed public with telegrams, published in the New York Herald, describing what he was seeing on the planet:


"September 2. Mars has two mountain ranges near the south pole. Melted snow has collected between them before flowing northward. In the equatorial mountain range, to the north of the gray regions, snow fell on the two summits on August 5 and melted again on August 7.


"October 6. Discovered forty small lakes on Mars."


Though recalled from Arequipa at the end of the opposition, Pickering's connection with Mars led him to become tutor to the well-to-do American amateur astronomer Percival Lowell, who hoped to find a site where the air was as steady as might be in which to set up an observatory specializing in the study of Mars. In 1894, he settled on "Mars's Hill," a low-lying mesa at Flagstaff, Arizona. Though Lowell and Pickering did not get along, and Pickering left Flagstaff after a year, Lowell continued his quest for the best conditions for studying Mars, exploring sites in Mexico, the Sahara, and - in 1907, at the peak of the Martian canal furor which he did so much to provoke -Chile for the purpose of studying Mars.


"Think back on '07," the Wall Street Journal mused as that year approached its close. "What has been in your opinion the most extraordinary event of the twelve months?" In the Journal's opinion, it was not the severe financial panic but "the proof afforded by astronomical observations that ... intelligent human life exists upon the planet Mars."


For the almost-perihelic opposition of July of that year, Lowell joined forces with David Peck Todd, professor of astronomy at Amherst College, to mount the most ambitious expedition of the opposition. On its results the expectations of many hung as to the resolution of the question of life on Mars. Todd was a world-class eclipse chaser -- Lowell himself had gone eclipse-trotting with him to Tripoli in 1900 -- and, at least in his own mind, a world-class skirt-chaser. (His wife Mabel once commented forlornly that it would be impossible to make a "monogamous animal" out of him.

Rather than remain on the sidelines while he cheated on her, Mabel engaged in her own love affairs, including a torrid one with the poet Emily Dickinson's brother Austen, as described in the book Austen and Mabel. For all that, the Todds continued to travel together, enjoying what can only be described as an open marriage and blazing a trail of sexual notoriety by Victorian standards.)


Lowell agreed to pay the charges needed to transport the Todds, young Lowell Observatory assistant Earl C. Slipher, and two other men, as well as Amherst College's 18-inch refractor to South America for the purpose of photographing Mars from the Andes. Photography had greatly improved since Benjamin Apthorp Gould of Argentina's Cordoba Observatory had obtained the first blurry image of the planet in 1879. It routinely registered the polar caps and dark areas, and seemed, in 1907, on the verge of recording fine details such as the canals. So much fanfare attended the sailing of the party from New York to South America by way of Panama that Slipher, arrived at the Canal-Zone (in Panama, not Mars!) informed his brother that "Lowell expedition to Andes" was sufficient address for mail.


The party set up their observing station at Alianza, Chile, a site 4,000 feet high from which Mars would glare down from the zenith. Seventy miles inland from the Port of Iquiqui, beyond the coast range of the Andes, it lay in the "rainless and almost cloudless waste" of the Tarapaca desert. Under these conditions, shelter for the telescope was unnecessary, and it was simply mounted in the open air, under the dome of the burnished and ineffable sky. Using a planetary camera designed by Todd, Slipher obtained 13,000 images of Mars. They were small, a quarter inch to the disk of the planet, but on the sharpest of them the canals seemed to be visible, as Todd excitedly cabled to Lowell. Magazines such as the Cosmopolitan, which had a circulation of over a million, clamored for rights to reprint the images, and Lowell telegraphed from Flagstaff: "Bravo!... The world, to judge from the English and American papers, is on the qui vive about the expedition.... They send me cables at their own extravagant expense and mention vague but huge (or they won't get 'em) sums for exclusive magazine rights for the photographs." In the end, Lowell had to serve an injunction on the Cosmopolitan to prevent them publishing the photographs, for which he claimed exclusive rights, in an article penned by Todd. The threat of legal action so scared the management that the January 1908 issue was delayed ten days.


In fact, it was all much ado about nothing. The fine details on the photographs were too delicate to reproduce, except if they were retouched; but then the evidentiary value was lost.


After his return from Chile, Todd's career went into rapid decline. He was forced to leave Amherst and became obsessed with ideas like communicating by with the Martians by radio. During the close 1924 opposition he prevailed on the military to briefly suspended radio transmissions in order not to interfere with any messages from Mars. By then he was clearly suffering the effects of tertiary syphilis; he spent his last years until his death in 1939 in an insane asylum. Mabel, who saved from obscurity the poems of her former-lover's sister, Emily Dickinson, died in 1934. Slipher remained at Lowell Observatory and became the most prolific photographer of Mars of his time. He led National Geographic sponsored photographic expeditions to Bloemfontein, South Africa in 1939, 1954, and 1956. He died in 1964, on the eve of the first of the Mariner flyby missions to the planet.


It was those flyby missions that finally demolished the canal system. We now know that the disk of Mars is swarmed over with so much detail that the eye and brain cannot grasp it all, but at times the illusion of lines and dots - Lowell's canals and oases - can be compelling. Observing Mars from a mountaintop in Chile in 1971, under the finest conditions he had ever known, the professional astronomer Peter Boyce had a view of the Syrtis Major hemisphere of Mars that startled him. A Lowellian system of canals and oases suddenly appeared. Of course, he knew that according to the spacecraft photographs there were supposed to be no canals -- yet even so, there they were, and they could not have been more unmistakable.


A clever magician uses the sleight of hand to perform tricks that the audience finds spellbinding, even though it knows better. What a master magician is Mars! It continues to cast its spells and to work its enchantment.


Bill SHEEHAN (Willmar, MN, USA)

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