Encke’s Comet, Celestial Poetics, and the Dawn of Popular Astronomy: How Emma Converse Became the Carl Sagan of the 19th Century
By Maria Popova
“A comet,” wrote Carl Sagan and Ann Druyan, “[is] a great clock, ticking out decades or geological ages once each perihelion passage, reminding us of the beauty and harmony of the Newtonian universe, and of the daunting insignificance of our place in space and time.” But a century before Sagan, another writer became the poet laureate of popular astronomy and distilled the science of space in luminous prose — Emma Converse (1820–1893), who pioneered the art of astropoetics in the 19th century. Her columns, syndicated widely in newspapers across the country, were among the first popular articles on astronomy to appear in any daily paper. Well before the first class of women astronomers graduated from Vassar and began revolutionizing our understanding of the universe, Converse was singlehandedly enchanting the common reader with the uncommon magic of the cosmos.
In an especially poetic piece published in Appleton’s Journal on January 6, 1872, Converse took up the subject of comets — in particular, Encke’s Comet, discovered nearly a century earlier, on January 17 of 1786.
Encke’s Comet is unusual for a number of reasons — not only does it pass closer to the Sun than Mercury, the innermost planet of the Solar System, once per its strikingly short 3.3-year orbit, but it also seems to defy Newton by deviating from the motion pattern predicted by his law of gravity and instead arriving at that point closest to the Sun a couple of hours early each orbit. The anomaly puzzled generations of astronomers, but its study, alongside the broader study of its kin, has helped illuminate the mysteries of the universe and even the probable origin of life on Earth.
Converse paints the backdrop of the comet’s significance:
Sir William Thompson [Lord Kelvin], the president of the British Association for the Advancement of Science, in his recent inaugural address startled his audience by the suggestive assertion that life on the earth may have had its origin from seeds borne to our earth by meteors, the remnants of former worlds. He united this theory with the partially-established one that comets and comets’ tails consist of meteoric rocks, becoming luminous by concussion, and a change of position in regard to our planet, thus divesting comets of the ancient superstition which made them the harbingers of war, pestilence, and famine, and transforming them into the beneficent creators who brought vegetation and life to the chaotic surface of the globe.
She returns to the particular subject of her article:
Encke’s comet is principally interesting for the reason that it performs its entire revolution within the boundaries of the solar system; that its period is the shortest of any comet whose revolution has been calculated; and that its twenty recorded returns give us a feeling of relationship which does not belong to any other individual of the cometic brotherhood. We hope that its present return to our neighborhood will give more light on the composition of the strange class to which it belongs.
It may seem that this comet is of little importance in the boundless world of space. But its short revolution of twelve hundred days illustrates the great laws which sway the material universe as fully as the vast sweep described by more distinguished members of the family, like the comet of 1680, whose perihelion was so near the sun that the heat on its surface was 25,600 times fiercer than that of an equatorial sunshine at noonday, and whose aphelion is so distant that it will not be reached for nearly 5,000 years… Its minute tail is fashioned by the same laws as that of the comet of 1744, whose six tails spread over the heavens like an immense fan; or like that of 1843, which stretched half-way across the sky at sunset; or the well-remembered one of 1858, called Donati’s comet, whose tail, with its superb cigarettelike form, says the late Sir John Herschel, “looked like a tall plume, wafted by the breeze!”
With her characteristic penchant for poetics, Converse turns from space to the Earth, bridging the magic of cosmic awe with the rigorous inquiries of science:
All over the scientific world, this little nebulous patch of light is being scrutinized by earnest gazers through the silent hours of starlit nights. The most powerful telescopes thus far have discovered no trace of a nucleus, and no shadow of a tail under its present condition of development; there is nothing to be seen but a fleecy cloudlet. That modern magician, the spectroscope, has also been faithfully applied to test the constitution of the celestial visitor.
Noting that such spectrographic analyses of the comet were being done at Washington’s Naval Observatory and the Harvard Observatory — which would soon become home to a brilliant team of unsung women astronomers — Converse turns a lyrical eye at once to the past and to the future of our celestial exploits:
The moment so long looked for may be nearer than we think, when, with a powerful grasp, like that of Newton, some watcher of the stars shall seize the secret of cometic history. Then will they still pursue their erratic course about the solar system, regulated by laws as easy of comprehension as those which sway the planets; then, also, will their fiery constituents be as fully determined as the grosser materials that make up the globe; and then will their use in the celestial economy be as plainly understood as the action of the sun on the planets that revolve around him! Fortunate is the observer who discovers the key to this celestial secret!
Complement with Converse’s scientific serenade to the evening sky and Étienne Léopold Trouvelot’s stunning 19th-century astronomical drawings, then leap forward with modern-day astropoetics maestro Alan Lightman on dark energy, the multiverse, and why we exist.
Published January 17, 2017