Tag Archives: astronomy

On blood moons and tetrads

lunar eclipse
“Lunar eclipse April 15 2014 California Alfredo Garcia Jr1” by Tomruen – [1]. Licensed under CC BY-SA 3.0 via Commons – https://commons.wikimedia.org/wiki/File:Lunar_eclipse_April_15_2014_California_Alfredo_Garcia_Jr1.jpg#/media/File:Lunar_eclipse_April_15_2014_California_Alfredo_Garcia_Jr1.jpg

There is a lunar eclipse coming the end of this month, and depending on who you ask it is significant for different reasons. In fact, there has been a lot of hype about this particular eclipse (or rather, series of eclipses) in some Christian circles with the term “blood moon tetrad” often being used in conjunction with prophetic claims. I’m certainly not a specialist in Biblical prophecy, interpretation, or the history of Israel, but I can unpack some of the sensationalized terminology here and help sort out the science behind the hype.

Let’s start with the term “blood moon.” The popular press has recently started using this term to refer to a lunar eclipse. Lunar eclipses happen quite frequently, usually twice a year, when the full Moon passes into the Earth’s shadow. This causes the Moon to fade in brightness over the period of a couple hours and often take on a deep red hue due to the Earth’s atmosphere and the way it scatters light.

Consider how the sky looks during a sunset: even though the Sun is hidden beneath the horizon, the atmosphere bends the red portions of sunlight toward us. From the Moon, during a lunar eclipse, the Sun is hidden behind the Earth. The glow of a ring of sunsets casts that red light onto the Moon’s surface, making it appear duly reddish or “blood red.” This effect can be heightened if the Moon is near the horizon, depending on atmospheric conditions.

So what about “tetrad”? There are different types of lunar eclipses. If the Moon only moves partly into the Earth’s shadow, it’s called a partial lunar eclipse. The eclipse of this month is the last in a series of four total eclipses, in which the Moon passes through the darkest portion of the Earth’s shadow. A series of four total lunar eclipses without any partial eclipses between is known as a tetrad. This current tetrad includes the total lunar eclipse of last April as well as the eclipses of April and October of last year.

How rare are such series of eclipses? Glancing through my copy of NASA’s huge “Five Millennium Canon of Lunar Eclipses,” which included information on all lunar eclipses from 2000 BC to 3000 AD, I see that over the past thirty years there was a tetrad in 2003/2004 and 1985/1986 (as well as several lunar “triads”). According to the website EarthSky.org, there will be eight tetrads in the twenty-first century, while the years 1701 to 1899 had none at all. There were five in the twentieth century.

So what does this all have to do with Biblical prophecy? According to some sources, this particular tetrad is unique because it lines up with specific Jewish holidays. Last year, the first lunar eclipse of the series fell during Passover, as did the eclipse of April of this year. Last year the October lunar eclipse was during Sukkot, or the Feast of Tabernacles, which again corresponds with this month’s eclipse.

The important thing to remember though is that the Jewish calendar (unlike ours) is a lunar calendar; its months correspond with the actual phases of the Moon. Both Passover and Sukkot begin on the fifteenth day of the Jewish month, which usually corresponds with the full Moon. And because lunar eclipses only happen when the Moon is full, it’s not strange there would be occasional line-ups between these holidays and a series of lunar eclipses. How occasional? Again, according to EarthSky.org, this has happened eight times since the birth of Christ.

And here’s where the prophet interpreters come in, offering links between the years in which a tetrad of lunar eclipses corresponded with these holidays and important events in the history of Israel. But that’s the problem: history is a complex, messy business, and the human mind is hard-wired to find patterns everywhere, even where they don’t exist. Plus, these “significant events” are subjective: how widely do you want to interpret what events are actually important? The tetrad of 1493-1494 is linked to the expulsion of the Jews from Spain, for instance, but the order for the expulsion wasn’t signed in these years and the persecution lasted for decades. Making 1493-1494 especially significant is arbitrary. And other events that would seem to be significant are ignored: there was no lunar tetrad, for instance, during the Holocaust. Finally, I should add that this whole claim of prophetic significance is offered by individuals outside the Jewish community with little insight or regard into what that community would actually consider culturally or historically important in their own past.

In my mind, searching for codes in the night sky is much less useful than simply appreciating the grandeur of astronomy for what it is. And this month, regardless of prophetic forecasts, we have the chance to witness one of nature’s most impressive spectacles. The “blood moon tetrad” will conclude with the total lunar eclipse beginning the evening of Sunday, September 27th. (If you’re still looking for cosmic coincidents, here’s another one: my birthday is September 27th.)

The full moon rises in the east at sunset that evening. By 9:15 the Moon has begun to enter the darkest portion of the Moon’s shadow, marking the most vivid phase of the eclipse. It will be at its darkest at about 9:45, and the moon will begin to emerge from deep shadow at about 10:20. The Moon will not be completely out of the Earth’s shadow, however, until after midnight. As far as visibility, this will be an easy lunar eclipse to observe—taking place when the Moon is high in the early part of the evening. (Last year I had to make students get up before dawn to spot the eclipse.) So definitely take the opportunity to wonder and ogle, but try not to prognosticate.

This column first appeared in the Kankakee Daily Journal, August 28th, 2015.

August offers a look at Lyra

When I talk to people about observing here in town, they often bemoan the fact that light pollution makes stargazing all but impossible from within the city limits.

Though it is true that observing from an urban setting doesn’t compare to an experience under truly dark skies, it’s certainly not the case that there’s nothing to see from one’s own backyard or even sidewalk.This month I’ll consider some of the sights in the constellation Lyra, which is almost directly overhead throughout August in early evening.

Lyra is a tiny constellation, but it holds a wealth of lovely double stars that are bright enough to be seen without a pilgrimage to the deep, dark countryside.

The constellation Lyra is easy to find on clear nights. Vega, its brightest star and the brightest star of summer, is nearly overhead at sunset. Vega marks one apex of the famous Summer Triangle, an asterism of three bright stars high in the summer skies. Lyra itself though is small formed of a triangle of stars attached to a larger parallelogram. Classically, the constellation was seen as a harp or lyre.


My observations are made with a six-inch reflecting telescope from my own yard in Kankakee, but a smaller telescope will reveal these sights as well. You’ll want to use eyepieces that give a relatively low magnification. (I used about 40x. Calculate the magnification of your eyepiece by dividing your telescope’s focal length by the focal length of your eyepiece. A shorter eyepiece focal length gives greater magnification.)

Sometimes you want higher magnification, as when you’re viewing the planets or the Moon and want to see details, but for the following views a lower magnification is better.

Start your tour with Vega, especially if you’re new to stargazing. A single star doesn’t look much different through a telescope, but this will give you a chance to align your finding scope (if your telescope has one) and test your instrument’s focus. It will also give you an idea of the seeing conditions for the night. If you can focus Vega down to a brilliant, sharp point, and if you can see one or two of its dimmer companions in your telescope’s field of view, you should be able to spot the rest of the objects in this list.

Hop down from Vega to Zeta Lyrae, the dim star where the triangle meets the parallelogram. This is one of the many double stars in Lyra. Double stars are great targets for light polluted skies. Unlike nebulae or galaxies, they are fairly bright and thus easy to enjoy even from one’s own backyard. Through even a small telescope, Zeta Lyrae is revealed to be a wide, uneven double, and many observers report seeing a beautiful color contrast between the component stars.

Moving up to the third star of the tiny triangle that makes up the top portion of Lyra, we find Epsilon Lyrae, one of the most popular double star systems in the sky and an example of why some observers (like me) get so excited about double stars. At 40x you may simply see what looks like a wide pair of white stars. But if you increase your magnification (I used 130x), you’ll see that each of these stars is actually itself a pair of stars. The entire system is known as the “Double-Double.” You’ll need a steady eye and good seeing to split them, but you’ll know if you’ve succeeded by noticing the orientation of each tight pair: they’re inclined at ninety-degrees to each other.

Moving back to a lower magnification, each of the stars at the apexes of Lyra’s parallelogram is a treat.

Delta Lyrae is a wide double star in a diffuse cluster of stars. One of the components is a lovely orange in contrast to the surrounding blue stars.

Beta Lyrae also is a group of colorful stars. (The Ring Nebula is nearby, halfway between Beta and Gamma Lyrae. From my front yard, the Ring Nebula at 70x looked like a faint smoke ring, barely visible.)

But my favorite sight of all in Lyra is a bit off the beaten path and not terribly well known. It’s sometimes called the “Double-Double’s double,” but I think it’s actually nicer than the more famous Double-Double. It’s a pair of double stars, like the Double-Double, known as Struve 2470 and 2474. They’re dimmer than the pair that make up Epsilon Lyrae, but because the components are farther apart they’re easier to split. They also have more marked colors, the brighter components appearing yellow in contrast to the dimmer bluish companions. Moreover, by some cosmic coincident the pairs are orientated in the same direction so they indeed look like almost perfect twin double stars in a single telescope eyepiece. This view alone would be proof enough for anyone who says the city skies are too bright to hold telescopic wonders.

Struve 2470 and 2474, the “Double-Double’s Double,” image from bestdoubles.wordpress.com.

This column first appeared in the Kankakee Daily Journal.

The Martian

The MartianThe Martian by Andy Weir

My rating: 4 of 5 stars

This is a book written by an engineer for engineers. I’m not an engineer. But I can’t lie and say I didn’t enjoy reading this one. I needed a beach book for my week in Michigan, and when this book appeared on the shelf (as books are wont to do on my wife’s side of the bookcase), I grabbed it. I had seen one of my honors students (an engineer) reading it and had read this fantastic quip on XKCD. And then I saw the movie trailer (which looks AWESOME), so that helped me finally jump on the bandwagon. (And I know this is a departure from my resolution to read fiction by minority authors, but– BEACH.)

Be advised, this is a book by an engineer written for engineers. Did I already say that? It is compelling. The idea is simple and devastating: in the near and pretty believable future, manned missions to Mars are a reality and as gritty and physical and dangerous as an actual mission to Mars would be. On one of these missions, an astronaut gets left behind, assumed dead. It turns out he’s not, and he has to figure out how to survive on Mars, NASA has to figure out what happened and what they can do to fix it, and the crew of his ship have to figure out whether they follow NASA’s lead or mutiny and risk their own lives to save him.

Most of the story was told in the form of journal entries made by the marooned astronaut, Mark Watney, during his time on the surface. Here’s where the whole thing at times felt like a long, science fiction McGyver episode. Mark explains in detail how he’ll provide water and oxygen for himself, how he’ll grow food, and how he’ll get around on the surface. These are gripping details for a few chapters, but they can’t keep a reader’s interest– even one who appreciates the thought and detail the author put into keeping this grounded in reality– forever. Mark himself is a sort of Everyman, competent, foul-mouthed, and with a dry sense of humor. His ordinariness at times though, in spite his incredible technical competence, seems hollow. Not once, for instance, do we find Mark describing the view of Mars out his hab suite windows or reflecting on the nature of his dilemma with anything other than a superficial “do or die” mentality. But then again, what are the chances NASA would be sending a philosopher into space?

Luckily, Weir– himself a software engineer– realizes that stories don’t work without people and that it’s going to be difficult to build suspense about whether Mark lives or dies with him reporting in at the end of each day. So the narrative switches up a few times and we get a glimpse into the lives of the people back on Earth working to send supplies to keep Mark alive and ultimately his shipmates as they learn his fate and decide what they need to do to save him (as well as occasionally some God’s-eye-view narrative of the lives of inanimate equipment parts and geological features about to fail, which oddly enough functions quite well to build suspense).

This is where the actual drama comes in, and for me the most exciting parts of the novel were where the crew of the Hermes had to wrestle with what it might cost them to return to Mars to save Mark. And this– the dynamics between crew members on a months-long voyage and the cost of rescue– is what I hope the upcoming movie plays up. This was the pivot-point of the novel, and it was enough pull to get me as a reader over the hump and into the second part of the book, which chronicles Mark again and all the technical challenges of piloting a rover across a good portion of Mars to arrive at the appropriate rondevouz point and make an orbital-return component capable to escape velocity.

Lots of science here. In fact, Mark’s not really the hero of the story so much as science is. Science, Weir is saying, can pretty much solve anything if we’re plucky enough to keep trying and make the sacrifices required. (He also says something about it being the nature of humans to want to help each other, which is quoted pretty much verbatim in the movie trailer.) Besides the scientific triumphalism (which SPOILER dictates how the book will end– there’s never any real question of Mark’s survival), he deftly sidesteps any deeper questions, such as whether there’s an appropriate cost for saving a single human life or whether humans belong on places like Mars at all. No sir, this is a book about engineering. But I have to admit a book that raises philosophical questions without addressing can be fine in its own right. Sometimes it’s okay to simply present the problem in a clear-eyed fashion and leave it to the reader to puzzle through like Mark had to puzzle through the reality of Mars.

It is a fun, compelling, riveting book, but it ultimately felt unfulfilling for me because the pieces that made it tick– the people, and particularly the crew of the Hermes— never got closure. That is, we learn Mark’s fate but we don’t any view of his reunions with the people who saved his life. That would all be a compelling follow-up novel: call it The Earthling. It could show Mark’s life returned as the most famous human on the planet and him interacting with the people who contributed to his rescue as well as his return voyage to Earth with his crew (as well as the implied hook-up with Mindy, the NASA worker who contributed to his recovery and about whom I can only assume there’s an in-joke here regarding “Mork and Mindy” with Weir’s proclivity for 70s television). But the book is still tight and cogent leaving all that up in the air, especially as messy inter-personal stuff like that would take the focus off the science.

New Horizons

108417main_image_feature_267_ajhfullImage courtesy NASA.gov.

Fast, small, cheap, and putting us in touch with the outer reaches of the solar system, the New Horizons spacecraft, which will reach its closest approach to Pluto this month on July 14th, is billed by NASA as the “smart phone” of interplanetary robotic explorers. The fastest spacecraft ever launched from Earth, New Horizons is an example compact, efficient engineering opening the door to new discoveries. This month the probe, launched nearly a decade ago in January of 2006, completes its three billion mile journey, the longest journey ever to a particular object in space.

Besides the technological achievements this plucky probe represents, New Horizons is a step into a new solar system frontier, a glimpse of a region of our own planetary system where we have not yet ventured. The close look at Pluto afforded by this mission is an opportunity for the first time to study the place where the solar system gets weird. Since tiny Pluto was serendipitously discovered in 1930 by Illinois native Clyde Tombaugh, we’ve known that it didn’t quite fit with the rest of the planets. We have small, rocky planets (Mercury, Venus, Earth, and Mars) in the interior of the solar system and large, gaseous planets (Jupiter, Saturn, Uranus, Neptune) on the periphery. Pluto—usually beyond Neptune and much smaller than any other planet—is the odd man out.

Yet it’s only recently that we’ve realized Pluto isn’t alone in its strangeness. Rather, it’s the first known object from a whole new region of the solar system. This region—which is turning out to be filled with small icy objects like Pluto—is known as the Kuiper Belt, and we still don’t know much about it. We do know that Pluto was only the first dwarf planet discovered in this region. Recently Pluto has been joined by the discovery of other dwarf planets beyond Neptune like Eris, Makemake, and Huamea. New Horizons affords the first close look at this strange region of space. Once it passes Pluto, the spacecraft may be redirected to pass another Kuiper Belt object.

Besides the Kuiper Belt, Pluto is itself still an oddity. It will be the first icy planet studied closely, for instance, and may help answer the question of whether certain types of comets are simply objects like Pluto that fall into the inner solar system. Pluto also offers an example of a gravitational oddity: along with its largest moon, Charon, Pluto is technically a double planet. Pluto and Charon orbit a common center of mass between the two objects, making them unique in the solar system by forming a double planet instead of simply a planet and moon.

And then there’s Pluto’s complicated system of newly discovered moons besides Charon. Tiny Nix, Hydra, Styx, and Kerberus have recently been shown to tumble about Pluto in a chaotic system. These miniscule objects have been studied using the Hubble Space Telescope, but New Horizons will provide the first opportunity to study them up close. Indeed, the presence of Pluto’s unexpectedly complex satellite system represents one of the large unknowns of the mission: is the space around Pluto empty or filled with debris that could pose a danger to the speeding spacecraft? The weeks leading up to New Horizon’s encounter with Pluto have been a time of suspense.

New Horizons is a fly-by mission, meaning that it’s not landing on Pluto’s surface (like the Mars rovers) nor is it entering orbit around the dwarf planet (like Cassini around Saturn or Messenger around Mercury). New Horizons will study Pluto from its closest distance of about six thousand miles on July 14th while barreling past the planet at nearly forty thousand mph. It has to be moving fast—it’s had over three billion miles to cover since leaving Earth almost ten years ago.

What sort of things do scientists hope to learn from this mission? For one thing, scientists want to better understand how Pluto “fits in” with the other planets of the solar system. What do its unique properties tell us about the origins and evolution of the solar system? For the first time this month, we’ll get a close look at the strange boundary region of the solar system that we’ve only ever been able to study from afar. As far as the solar system goes, it really is “the final frontier,” and we’ll get our first close views of it this month.

This article first appeared on Friday, July 10th, 2015 in the Kankakee Daily Journal.

Double and Multiple Stars and How to Observe Them

Double and Multiple Stars: And How to Observe ThemDouble and Multiple Stars: And How to Observe Them by James Mullaney

My rating: 4 of 5 stars

“The amateur astronomer has access at all times to the original objects of his study; the masterworks of the heavens belong to him as much as to the great observatories of the world. And there is no priviledge like that of being allowed to stand in the presence of the original.”
-Robert Burnham, Jr. (my emphasis)

One of my goals this summer has been to spend more time with the fleet of telescopes I have access to through my university. I teach about the night sky and I research scientists who spent their lives studying the night sky, but I find I’ve had very few opportunities myself to get to know the sky outside the simulated confines of the planetarium dome.

Double stars are an ideal target for starting out. Unlike nebula, galaxies, and other deep sky targets, double stars are bright and fairly easy to spot. They’re like tiny gems hidden up there in the sky. The sky is a map, and sometimes it’s hard to learn. It’s often difficult to tell whether the star you have in your sights is actually the star on your charts that you think you might be looking at. Yet if your resources tells you it’s supposed to be a tight, nearly equal double with a separation of six arcseconds, and if you see it staring back at you like a pair of distant celestial headlights, then you know you’ve found it. They’re targets that are immediately rewarding, bright enough to spot on moonlit nights or in light polluted skies, and varied enough to be interesting.

Take separation, for instance. My six-inch reflecting telescope hasn’t had any troubles on the evenings I’ve been observing splitting pairs down to a separation of about four arcseconds. Izar in Bootes, with a separation of just under three arcseconds, shows a hint of the bluish companion star elongated from the edge of the brighter orangish primary. Depending on the viewing conditions each night, my scope should theoretically be able to distinguish even closer pairs, but the challenge of realizing this is part of what makes these targets rewarding.

Then there’s color contrast. You view an image from the Hubble Space Telescope, and it seems like space is vibrant with color. Yet actually viewing a nebulae or galaxy with the eye in a telescope eyepiece reveals perhaps a hint of greenish glow at best. With double stars though, the color contrast in star pairs is often quite dramatic. Different people observe different colors, which are artifacts of both intrinsic color differences in the stars and contrast between them.

Finally there’s simply the conceptualization of what you’re actually looking at. Most very close doubles are binary stars, which means systems of two (or more) stars rotating around a common center of mass. These are the objects John Herschel and others were studying in the early 1800s in order to directly calculate stellar masses. (They’re still the only method we have for directly measuring the mass of stars.) These star pairs, I argue in my dissertation, were instrumental in changing the way people thought of the stars: seeing them as vast physical systems. They continue to inform our popular stellar conceptions; recall the iconic scene of the double sunset on Tatooine in Star Wars.

Fortunate for the enthusiast like me there are a host of guides and resources regarding showcase double stars to observe. The Cambridge Double Star Atlas is a great place to start, and banking on the usefulness of that resource I purchased this observing guide by one of the authors of that atlas: Double and Multiple Stars and How to Observe Them. This slim guide is an ideal introduction to the topic, exploring in an overview the practical aspects of observing these objects but also going into some detail on the real scientific contributions an amateur could pursue. Mullaney’s enthusiasm for the topic is contagious, from the introductory physical descriptions of double stars as astrophysical objects (reminescent of the language popularizers were using to describe them in the 19th century) to his own advice on keeping observing journals.

Though the prose is good, I had two big complaints with the work. The first is the quality of printing. It was clear as soon as I cracked the cover that this was a print-on-demand title by Springer, with the pages consisting of scans of a PDF or other electronic image. The text is not crisp or clear, and on many pages there is grey stippling in what should be the white space between letters and lines. It’s not bad enough to make the text illegible, but it is annoying. The second is that Mullaney says the work is really two resources in one: a background or overview on double stars and observing them, along with an observing guide of locations and descriptions for one hundred showcase double stars. Yet– though I haven’t compared it star to star– this list seems to duplicate the list provided in the Cambridge Double Star Atlas. So if you’re looking for a lot of new double stars to admire, you might be disappointed.

“What we need is a big telescope in every village and hamlet and some bloke there with that fire in his eyes who can show something of the glory the world sails in.”
-Graham Loftus (my emphasis)

Mason & Dixon

Mason and DixonMason and Dixon by Thomas Pynchon

My rating: 2 of 5 stars

The past is a different country, but in Pynchon’s work it might as well be a different planet– or at least a different reality. It is without a doubt someplace foreign, somewhere on the boundary of narrative and myth. Pynchon’s Mason & Dixon is, superficially, a historical fiction recounting the work of the British astronomers Charles Mason (1728–1786) and Jeremiah Dixon (1733–1779), who observed the 1761 transit of Venus across the Sun from the Cape of Good Hope but are better known today for measuring the colonial boundary known today as the Mason-Dixon line.

Mason & Dixon had been recommended to me because of its treatment of the history of astronomy. And there is indeed some great historical astronomy in here. I tagged a passage for my introductory astronomy class to read to illustrate that much of what we know as astronomy in the eighteenth century had nothing to do with probing the nature of celestial objects but was instead a means of measuring position and distances on the Earth’s surface. The primary characters are historical personages, and the narration frequently alludes to Mason’s journals. I wish, however, Pynchon would have explained in either a prefix or an afterward exactly what his sources were that formed the kernel of truth behind what was in many respects a shifting landscape of surreality.

On the skeleton of a historical framework, Pynchon rears a sprawling, phantasmagoric edifice that belies any sort of easy classification. Early on in the narrative the main characters meet a talking dog. Things get stranger from there, and their travels include encounters with a sentient, robotic duck, erotic Jesuit assassins, a Jewish Golem as large as a mountain, ghosts, giant vegetables, and signs of a pre-historic advanced civilization among ancient burial mounds. Most of the action takes place in the wilds of colonial America, where Pynchon uses his stream-of-consciousness approach to paint a wilderness of our own national legends and myths. It is a realm where what we think of as “real” history blends with history-that-could-have-been, or should have been, or was once imagined.

Pynchon’s writing style doesn’t make it any easier for the casual reader. The first thing to master is the eighteenth-century spellings and capitalizations, carried throughout the work. To be fair, once you’ve gotten used to this, it is no longer quite so noticeable and indeed deepens the feeling that you’re actually experiencing life as it was lived and thought over two hundred years ago. The following passage gives a good feeling for Pynchon’s stylistic approach. All of the ellipses are true to the text:

“What Machine is it,” young Cherrycoke later bade himself goodnight, “that bears us along so relentlessly? We go rattling thro’ another Day,– another Year,– as thro’ an empty Town without a Name, in the Midnight . . . we have but Memories of some Pause at the Pleasure-Spas of our younger Days, the Maidens, the Cards, the Claret,– we seek to extend our stay, but now a silent Functionary in dark Livery indicates it is time to re-board the Coach,and resume the Journey. Long before the Destination, moreover, shall this Machine come abruptly to a Stop . . . gather’d dense with Fear, shall we open the Door to confer with the Driver,. . . no Horses, . . . only the Machine, fading as we stand, and a Prairie of desperate Immensity. . . .”

What is harder to come to grips with is Pynchon’s casual treatment of chronology. Dialogue between characters describing a past event will move without warning into a firsthand narrative of said event with no transition. Pynchon’s approach of presenting the entire narrative as a story being told as a recollection by one of Mason and Dixon’s traveling companions in post-independence Philadelphia and switching back and forth between the narrative and description of what’s happening in this Philadelphia drawing room– frequent at first but falling away by the novel’s end– is also disconcerting. All of these scene and temporal shifts come on top of the reality-surreality disjunction that runs through the entire work, contributing to a sense vertigo that makes the whole thing– the primary extent of which chronicles the wanderings of the surveyors in America– feel like an extended fever dream.

It was beautiful in many places, and the weirdness and wonder of the story itself hung nicely with the practice of astronomy during this period, often portrayed in other sources as dull and unromantic. Pynchon plays with connections between carving lines of latitude across a wilderness and early modern (and lingering) beliefs in lines of energy and occult forces across landscapes. (Dixon, we learn, spent his student years not only learning how to mark surveying lines but also using them to fly across the English countryside on a broomstick by night.) But the sheer volume of the tale and its dizzying arabesques of flashback and fantasy and story within story grew (for me) wearing. Maybe Pynchon was making us feel the grind of Mason and Dixon across the unexplored countryside, driving a carefully calibrated visto across America’s “dreamtime,” but all of their eastward and westward peregrinations started to blend together in my own mind. What was I supposed to find in Mason’s melancholy and Dixon’s tales under those strange stars?

The strongest aspect of the story was the relationship between the two astronomer-surveyors, which is played to an excellent effect in the novel’s beginning, during their time at the Cape of Good Hope in South Africa, loses momentum in the bulk of the novel, and only reappears after they have returned to England at the novel’s conclusion. In between, for much of the work, I was as lost as Pynchon makes it feel Mason and Dixon were themselves, with only their lenses and latitudes to guide them. It’s a journey with no real destination– into the wilderness and back, and Pynchon shows you that not even the astronomers themselves were satisfied with it, leaving the reader with ghosts and narrative echoes: an imagined image of them continuing westward and Mason at long last returning (maybe?) from England to America to die.

“Meanwhile, there all of you are, accosting Strangers in Taverns, spilling forth your Sorrows, Gratis. One day, if it be his Will, God will seize and shake you like wayward daughters, and you will thenceforward give nothing away for free.”


Sometimes I’m a lazy stargazer. The first lunar eclipse of the year was April 15th. I wrote a post about it on the Adler Planetarium blog. But when it came to setting the alarm to get up in the middle of the night to view it, I was secretly relieved to go to bed to an overcast sky. William Herschel used to fall asleep reading astronomy books in bed. He, of course, eventually got out under the night sky. I often don’t get beyond the books in bed.

Which is perhaps one reason why the history of astronomy appeals to me. I admit it: sometimes I like reading about the discoveries made by observers throughout history more than I like sitting under a cold observatory dome alone at night. Books don’t cloud over. Manuscript collections usually can only be visited by day. If I fall asleep over my work, there’s no real fear– as there was for the Herschels– of falling off a telescope platform.

I do wish though I had caught the most recent lunar eclipse. They’re slow events, more sublime than spectacular. Not like a solar eclipse (which I have never witnessed, though 2017 is fast approaching).

The most recent display I curated at the Adler was of eclipse depictions throughout history. These are all from the works on paper collection at the Adler (maps, diagrams, pictures, things that can be hung on a wall). The images really are quite nice, though the pictures I took don’t do them justice. (The gallery has subdued lighting, and a camera flash would have only created glare.) My favorite is of a broadside poster printed in the 1760s in England providing information on an upcoming solar eclipse. This would have been hung in a public place and is an early form of public science education, explaining what causes the eclipse and what the public could expect to see.

There’s a diagram from a medieval textbook as well, illustrating how the shape of the Earth can be deduced from the shape of the shadow during a lunar eclipse, and a few other images.

If you’re in Chicago, stop by the planetarium and take a look.


Lunar Frontiers


For the past two-and-a-half years I have served as a research and curatorial intern at the Adler Planetarium & Astronomy Museum as part of my fellowship at the University of Notre Dame. Much of my work there has involved creating and curating a database of surviving pre-1775 refracting telescopes from around the world. Lately I have had the opportunity to help select artifacts and write up descriptions for some temporary exhibits. This was my first, part of a display on lunar maps and globes.

I was surprised how challenging it was to present the information on these objects via concise captions that were accessible yet accurate and retained the details that made them such interesting pieces. This particular display contained three lunar globes from the Adler’s collection as well as a lunar atlas and telescope. I’ve included captions and images of my favorite objects below.

DSCF3900 DSCF3906

DSCF3902 DSCF3908

This last globe offered a mystery, as a previous owner had affixed unlabeled colored markers at various locations. A bit of homework indicated they corresponded with various lunar landings and helped estimate the globe’s date. If you’re in Chicago, head to the Adler and check them out!