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Encke’s Comet, Celestial Poetics, and the Dawn of Popular Astronomy: How Emma Converse Became the Carl Sagan of the 19th Century

“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.”

“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.

Emma M. Converse
Emma M. Converse

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.

Drawing of a comet, similar in appearance to Encke’s Comet, from The Comet Book, 1578. (Available as a print.)

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.

The great comet of 1881, observed on June 26, 1:30 A.M.
One of Étienne Léopold Trouvelot’s stunning 19th-century astronomical drawings. (Available as a print.)

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!”

Art from The Comet Book, 1578. (Available as a print.)

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.


Wonder-Sighting in the Medieval World: Stunning Sixteenth-Century Drawings of Comets, with Carl Sagan’s Poetic Meditation on Their Science

“A comet 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.”

Wonder-Sighting in the Medieval World: Stunning Sixteenth-Century Drawings of Comets, with Carl Sagan’s Poetic Meditation on Their Science

In 1985, Carl Sagan and Ann Druyan wrote in the introduction to their book Comet (public library):

Before the Earth was formed, there were comets here. Afterwards, and for all subsequent eons, comets have graced our skies. But until very recently, the comets performed without an audience; there was, as yet, no consciousness to wonder at their beauty. This all changed a few million years ago, but it was not until the last ten millennia or so that we began to make permanent records of our thoughts and feelings. Ever since, comets have left a good deal more than dust and gas in their wakes; they have trailed images, poetry, questions, and insights.

Four centuries before Sagan, two before comet-huntress Caroline Herschel spearheaded the systematic scientific study of comets, and one before Johannes Hevelius created his intricate comet drawings, an author and illustrator whose name or names remain lost to history produced one of the most breathtaking such works of “images, poetry, questions, and insights” inspired by comets: Kometenbuch, or The Comet Book, created in 1587 in what was then Flanders and is now France.

Available as a print.
Available as a print.

More akin to the Medieval Book of Miracles than to modern popular science — this, after all, was a pre-Newtonian world in which Galileo was still a student — the book concerns itself with the various superstitions about comets, the periodicity of which triggered the human mind’s pattern-seeking propensity: they came to be seen as omens of drought, famine, or bloodshed to come. As such, this stunningly illustrated book stands as a testament, both beautiful and tragic, to the perennial human tendency toward filling the void of fact with fictions that alleviate the anxiety of the unknown.

Available as a print.
Available as a print.

It is also an invaluable piece of media history — sightings of “wonders,” comets chief among them, were major news in that era, but until the invention of the printing press just a couple of decades earlier, they were transmitted only by word of mouth and one-on-one letter correspondence. Superstitions and mythical beliefs like those surrounding comet sightings are among the oldest and most virulent of memes; pamphlets like The Comet Book became a key early medium of memetic transmission.

Available as a print.
Available as a print.
Available as a print.
Available as a print.
Available as a print.
Available as a print.
Available as a print.

For a counterpart from across the precipice between the pre-scientific and scientific worlds, see French artist and astronomer Étienne Léopold Trouvelot’s stunning astronomical drawings created three centuries later at the Harvard Observatory, then let Sagan and Druyan take us out:

Comets may act as the creators, the preservers, and the destroyers of life on Earth. A surviving dinosaur might have reason to mistrust them, but humans might more appropriately consider the comets in a favorable light—as bringers of the stuff of life to Earth, as ocean-builders, as the agency that removed the competition and made possible the success of our mammalian ancestors, as possible future outposts of our species, and as providers of a timely reminder about large explosions and the climate of the Earth.

A comet is also a visitor from the frigid interstellar night that constitutes by far the greatest part of the known universe. And a comet is, further, 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. If, by chance, the period of a bright comet happens to be the same as a human lifetime, we invest it with a more personal significance. It reminds us of our mortality.

Public domain images courtesy of Open Repository Kassel


Carl Sagan on Moving Beyond Us vs. Them, Bridging Conviction with Compassion, and Meeting Ignorance with Kindness

“In the course of looking deeply within ourselves, we may challenge notions that give comfort before the terrors of the world.”

“Unless we are very, very careful,” wrote psychologist-turned-artist Anne Truitt in contemplating compassion and the cure for our chronic self-righteousness, “we doom each other by holding onto images of one another based on preconceptions that are in turn based on indifference to what is other than ourselves.” She urged for “the honoring of others in a way that grants them the grace of their own autonomy and allows mutual discovery.” But how are we to find in ourselves the capacity — the willingness — to honor otherness where we see only ignorance and bigotry in beliefs not only diametrically opposed to our own but dangerous to the very fabric of society?

That’s what Carl Sagan (November 9, 1934–December 20, 1996) explores with characteristic intelligence and generosity of spirit in the seventeenth chapter of The Demon-Haunted World: Science as a Candle in the Dark (public library) — the masterwork published shortly before his death, which gave us Sagan on science as a tool of democracy and his indispensable Baloney Detection Kit.

Sagan considers how we can bridge conviction and compassion in dealing with those who disagree with and even attack our beliefs. Although he addresses the particular problems of pseudoscience and superstition, his elegant and empathetic argument applies to any form of ignorance and bigotry. He explores how we can remain sure-footed and rooted in truth and reason when confronted with such dangerous ideologies, but also have a humane and compassionate intention to understand the deeper fears and anxieties out of which such unreasonable beliefs arise in those who hold them

He writes:

When we are asked to swear in American courts of law — that we will tell “the truth, the whole truth, and nothing but the truth” — we are being asked the impossible. It is simply beyond our powers. Our memories are fallible; even scientific truth is merely an approximation; and we are ignorant about nearly all of the Universe…


If it is to be applied consistently, science imposes, in exchange for its manifold gifts, a certain onerous burden: We are enjoined, no matter how uncomfortable it might be, to consider ourselves and our cultural institutions scientifically — not to accept uncritically whatever we’re told; to surmount as best we can our hopes, conceits, and unexamined beliefs; to view ourselves as we really are… Because its explanatory power is so great, once you get the hang of scientific reasoning you’re eager to apply it everywhere. However, in the course of looking deeply within ourselves, we may challenge notions that give comfort before the terrors of the world.

Sagan notes that all of us are deeply attached to and even defined by our beliefs, for they define our reality and are thus elemental to our very selves, so any challenge to our core beliefs tends to feel like a personal attack. This is equally true of ourselves as it is of those who hold opposing beliefs — such is the human condition. He considers how we can reconcile our sense of intellectual righteousness with our human fallibility:

In the way that skepticism is sometimes applied to issues of public concern, there is a tendency to belittle, to condescend, to ignore the fact that, deluded or not, supporters of superstition and pseudoscience are human beings with real feelings, who, like the skeptics, are trying to figure out how the world works and what our role in it might be. Their motives are in many cases consonant with science. If their culture has not given them all the tools they need to pursue this great quest, let us temper our criticism with kindness. None of us comes fully equipped.

But kindness, Sagan cautions, doesn’t mean assent — there are instances, like when we are faced with bigotry and hate speech, in which we absolutely must confront and critique these harmful beliefs, for “every silent assent will encourage [the person] next time, and every vigorous dissent will cause him next time to think twice.” He writes:

If we offer too much silent assent about [ignorance] — even when it seems to be doing a little good — we abet a general climate in which skepticism is considered impolite, science tiresome, and rigorous thinking somehow stuffy and inappropriate. Figuring out a prudent balance takes wisdom.

The greatest detriment to reason, Sagan argues, is that we let our reasonable and righteous convictions slip into self-righteousness, that deadly force of polarization:

The chief deficiency I see in the skeptical movement is in its polarization: Us vs. Them — the sense that we have a monopoly on the truth; that those other people who believe in all these stupid doctrines are morons; that if you’re sensible, you’ll listen to us; and if not, you’re beyond redemption. This is unconstructive… Whereas, a compassionate approach that from the beginning acknowledges the human roots of pseudoscience and superstition might be much more widely accepted. If we understand this, then of course we feel the uncertainty and pain of the abductees, or those who dare not leave home without consulting their horoscopes, or those who pin their hopes on crystals from Atlantis.

Or, say, those who vote for a racist, sexist, homophobic, misogynistic, climate-change-denying political leader.

Sagan’s central point is that we humans — all of us — are greatly perturbed by fear, anxiety, and uncertainty, and in seeking to becalm ourselves, we sometimes anchor ourselves to irrational and ignorant ideologies that offer certitude and stability, however illusory. In understanding those who succumb to such false refuges, Sagan calls for “compassion for kindred spirits in a common quest.” Echoing 21-year-old Hillary Rodham’s precocious assertion that “we are all of us exploring a world that none of us understand,” he argues that the dangerous beliefs of ignorance arise from “the feeling of powerlessness in a complex, troublesome and unpredictable world.”

In envisioning a society capable of cultivating both critical thinking and kindness, Sagan’s insistence on the role and responsibility of the media resonates with especial poignancy today:

Both skepticism and wonder are skills that need honing and practice. Their harmonious marriage within the mind of every schoolchild ought to be a principal goal of public education. I’d love to see such a domestic felicity portrayed in the media, television especially: a community of people really working the mix — full of wonder, generously open to every notion, dismissing nothing except for good reason, but at the same time, and as second nature, demanding stringent standards of evidence — and these standards applied with at least as much rigor to what they hold dear as to what they are tempted to reject with impunity.

The Demon-Haunted World remains one of the great intellectual manifestos of the past century. Complement it with Sagan on science and spirituality, his timeless toolkit for critical thinking, and this lovely animated adaptation of his famous Pale Blue Dot monologue about our place in the cosmos.


Carl Sagan on Humility, Science as a Tool of Democracy, and the Value of Uncertainty

“Science is a way to call the bluff of those who only pretend to knowledge… It can tell us when we’re being lied to. It provides a mid-course correction to our mistakes.”

“Without science, democracy is impossible,” Bertrand Russell wrote in his foundational 1926 treatise on education and the good life. Three generations later, Carl Sagan (November 9, 1934–December 20, 1996) — another one of our civilization’s most inspired minds and greatest champions of reason — picked up where Russell left off to make an elegant case for the humanizing power of science, its vitality to democracy, and how applying the scientific way of thinking to everyday life refines our intellectual and moral integrity.

In his 1995 masterwork The Demon-Haunted World: Science as a Candle in the Dark (public library) — the source of his indispensable Baloney Detection Kit — Sagan writes:

Avoidable human misery is more often caused not so much by stupidity as by ignorance, particularly our ignorance about ourselves… Whenever our ethnic or national prejudices are aroused, in times of scarcity, during challenges to national self-esteem or nerve, when we agonize about our diminished cosmic place and purpose, or when fanaticism is bubbling up around us — then, habits of thought familiar from ages past reach for the controls.

The true power of science, Sagan suggests, lies not in feeding into our culture’s addiction to simplistic and ready-made answers but in its methodical dedication to asking what Hannah Arendt called the “unanswerable questions” that make us human, then devising tools for testing their proposed answers:

There is much that science doesn’t understand, many mysteries still to be resolved. In a Universe tens of billions of light-years across and some ten or fifteen billion years old, this may be the case forever.


Science is far from a perfect instrument of knowledge. It’s just the best we have. In this respect, as in many others, it’s like democracy. Science by itself cannot advocate courses of human action, but it can certainly illuminate the possible consequences of alternative courses of action.

The scientific way of thinking is at once imaginative and disciplined. This is central to its success. Science invites us to let the facts in, even when they don’t conform to our preconceptions. It counsels us to carry alternative hypotheses in our heads and see which best fit the facts. It urges on us a delicate balance between no-holds-barred openness to new ideas, however heretical, and the most rigorous skeptical scrutiny of everything — new ideas and established wisdom. This kind of thinking is also an essential tool for a democracy in an age of change.

Art by Olivier Tallec from Louis I, King of the Sheep
Art by Olivier Tallec from Louis I, King of the Sheep

The scientific way of thinking, Sagan asserts, counters our perilous compulsion for certainty with systematic assurance that uncertainty is the only arrow of progress and error the only catalyst of growth:

Humans may crave absolute certainty; they may aspire to it; they may pretend, as partisans of certain religions do, to have attained it. But the history of science — by far the most successful claim to knowledge accessible to humans — teaches that the most we can hope for is successive improvement in our understanding, learning from our mistakes, an asymptotic approach to the Universe, but with the proviso that absolute certainty will always elude us.

We will always be mired in error. The most each generation can hope for is to reduce the error bars a little, and to add to the body of data to which error bars apply. The error bar is a pervasive, visible self-assessment of the reliability of our knowledge.

In this continual self-assessment, Sagan argues, lies the singular potency of science as a tool for advancing society:

The reason science works so well is partly that built-in error-correcting machinery. There are no forbidden questions in science, no matters too sensitive or delicate to be probed, no sacred truths. That openness to new ideas, combined with the most rigorous, skeptical scrutiny of all ideas, sifts the wheat from the chaff. It makes no difference how smart, august, or beloved you are. You must prove your case in the face of determined, expert criticism. Diversity and debate are valued. Opinions are encouraged to contend — substantively and in depth.


Science is part and parcel humility. Scientists do not seek to impose their needs and wants on Nature, but instead humbly interrogate Nature and take seriously what they find. We are aware that revered scientists have been wrong. We understand human imperfection. We insist on independent and — to the extent possible — quantitative verification of proposed tenets of belief. We are constantly prodding, challenging, seeking contradictions or small, persistent residual errors, proposing alternative explanations, encouraging heresy. We give our highest rewards to those who convincingly disprove established beliefs.

Embracing this ethos is an exercise in willingly refining our intellectual and ideological imperfections. Sagan captures this with elegant simplicity:

Valid criticism does you a favor.

He returns to the greatest promise of science as fertilizer for intellectual and spiritual growth, a democratic tool of social change, and a framework for civilizational advancement:

Science is a way to call the bluff of those who only pretend to knowledge. It is a bulwark against mysticism, against superstition, against religion misapplied to where it has no business being. If we’re true to its values, it can tell us when we’re being lied to. It provides a mid-course correction to our mistakes.


Finding the occasional straw of truth awash in a great ocean of confusion and bamboozle requires vigilance, dedication, and courage. But if we don’t practice these tough habits of thought, we cannot hope to solve the truly serious problems that face us.

Complement the enduringly elevating The Demon-Haunted World with Sagan on science and spirituality, the vital balance between skepticism and openness, his reading list, and this wonderful animated adaptation of his famous Pale Blue Dot monologue, then revisit cosmologist Lisa Randall on the crucial difference in how art, religion, and science explain the universe and Neil deGrasse Tyson’s touching remembrance of Sagan.


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