Galileo wasn't the first to the Moon

By Phil Plait | January 14, 2009 9:39 am

One of the most common misconceptions people have about astronomy is that Galileo invented the telescope. We know he didn’t; it had been around for years before he used one. What he did do was make one himself that was a big improvement over what had been done previously, and was among the first to turn it to the skies.

But that last part is important: he was among the first. He wasn’t the first person to use the telescope to look at astronomical objects, and he wasn’t even the first to document what he saw!

The first telescopic map of the Moon ever made, by Thomas Harriot in July, 1609.
Credit Lord Egremont and the RAS.

The image above is the first known drawing of the Moon made using a telescope. It was done by Thomas Harriot in July 1609, many months before Galileo published his own drawings. It’s crude, to be sure, but it shows that Galileo was not the first to set eyes on the Moon using the new instrument. Harriot was a mathematician and astronomer, and apparently beat Galileo in observing the skies by many months. The whole story is detailed by astronomical historian Allan Chapman at the University of Oxford. He wrote an article on this that will be published in the February edition of Astronomy and Geophysics. He gives evidence, from letters sent by Harriot to friends, that at least some of these drawings were made before Galileo’s.

Not to downplay what Galileo did! He was a pioneer in astronomy, and his careful observations are one of the reasons we remember him today, and are celebrating the International Year of Astronomy this year. But what you have to understand that one reason we celebrate Galileo’s contributions is because Galileo was very good at self-promotion. He published his drawings, while Harriot did not.

Of course, Galileo’s self-image is what got him into so much trouble later in life. He went way out of his way to insult the Pope and the Church, and was pretty much a huge jerk about it. The Church at the time was not exactly the picture of acceptance and tolerance, but I think even Mahatma Gandhi would have poked Galileo in the eye after being around him for a few minutes. Obviously, self-promotion has its place. But you have to remember others did good work, too.

A map of the entire Moon’s face made by Harriot.
Credit Lord Egremont and the RAS.

This map made above is pretty amazing. It was made by Harriot around 1613, around the time he suddenly (and for unknown reasons) stopped observing the sky. I’ve spent my fair share of time eyeballing the Moon, and this is a pretty decent map, certainly way better than I could do, even with the far-superior optics in my own telescope. Harriot independently discovered sunspots, and observed Jupiter’s moons (though after Galileo discovered and announced them; to his credit Harriot timed carefully the motions of the moons, and his observations have been confirmed).

As far as his stopping observing, it’s possible that with the crude instruments available to him, Harriot had pushed the state-of-the-art as far as he could. Galileo’s superior telescope let him do more, but I think we need to remember Thomas Harriot during this celebratory year. If you happen to peer through a telescope at the Moon, or Saturn, or some other celestial object this year, take a moment to remember those people who, four centuries earlier, were doing it for the very first time, and try to imagine what it must have been like to see a whole new world — a new Universe — open up in front of them.

CATEGORIZED UNDER: Astronomy, Cool stuff

Comments (53)

  1. Brian

    Check out that unlabeled item in the center.Is that another point of interest, or just the mark left behind by his compass when he drew the outline?

    In any case, it’s a beautiful map. (The fullsize image makes a pretty decent desktop background, too.)

  2. chaboyax

    i saw this on this months sky at night here in the uk
    that map is amazing seeing as it was drawn 400 years ago with a scope most of us wouldn t even bother with
    still bet he had nice dark skys

  3. David Schrimpf

    What did Galileo do or say to the Pope and Church that you find hugely jerky?

  4. Apart from “self promotion” (I am not sure what to think of this dig at Galileo, but then I am not an expert on his life/personality), we remember Galileo because he interpreted what he saw, rather than merely reporting or drawing. Seeing bright dots around Jupiter is one thing. Repeatedly observing them to see them change position, and interpreting this as a moon system in orbit around Jupiter is quite another.


    Phil Plait:

    This map made above is pretty amazing. It was made by Harriot around 1613, around the time he suddenly (and for unknown reasons) stopped observing the sky.

    According to Wikipedia, in 1615 or 1616, Thomas Harriot wrote to an unknown friend with medical expertise, describing what would have been the reason for the eruption of a cancerous ulcer on his lip. This progressed until 1621, when he was living with a friend named Thomas Buckner on Threadneedle Street, where he died on 2 July 1621. Several sources describe his condition for having cancer of the nose. In either case, Harriot apparently died from skin cancer.

  6. SteveG

    Perhaps we should be naming the next satellite / moon / asteroid after the noble Mr. Harriot.

  7. I guess this shows something isn’t science until it’s published – observation, experiment, and theory aren’t enough. Galileo may have intended self-promotion, but he achieved the promotion of (the new Copernican) astronomy. Which is why we remember him rather than Harriot (or Simon Marius, for that matter).

  8. Cheyenne

    It is so beyond cool to think of what the scientists and engineers are giving us in this day and age. Galileo’s ‘scope has been upgraded to-

    Hubble, Herschel, Kepler, Webb, Allen, VLA, Spitzer, Planck, ALMA, the whole lots in Hawaii, Chile, Arizona, Antarctica, and even flying around on balloons and modified 747’s and….pant pant…need breath……science rocks. The Casbah.

  9. Thanny

    “The Church at the time was not exactly the picture of acceptance and tolerance”

    That has got to be the understatement of the year thus far. This is also the first reference I’ve seen suggesting that Galileo was being a jerk, aside from Xian apologists who attempt to defend the completely indefensible actions of the Church.

    Beyond that, that first drawing of the moon is crude even by the standards of what one can see with the naked eye. The map clearly requires a telescopic view, but what evidence is there to suggest that the drawing was made at an eyepiece at all?

  10. Off topic (a bit):
    Everyone take a look at Astronomy Picture of the (to)Day
    (click my nick)

    Looks awesome.

  11. Hmm. I was under the impression that very little time passed between Lippershey’s telescope and Galileo’s (months, at best). Just because Galileo didn’t publish immediately doesn’t mean he wasn’t making observations, right?

  12. Read the history of Galileo and the Church. His writings mocked the Pope and the Church. The Pope had been a friend of Galileo’s before becoming the pontiff, so was lenient at first, but Galileo was such an arrogant jerk that eventually action had to be taken.

  13. “around the time he suddenly (and for unknown reasons) stopped observing the sky.”


  14. RawheaD

    Loved this post, Phil. I hope there will be a lot like this (i.e., bringing some intellectual history of astronomy into perspective), especially this year being what it is.

  15. kuhnigget

    Nice. I especially like the suggestion to try and imagine what it would have been like to see objects like the moon and Jupiter – and especially the stars of the Milky Way – for the first time! Without having already planted in your head an idea of what you are about to see…wow. Just think of the sudden expansion of the universe that Galileo must have grasped.

    @ Thanny:

    Beyond that, that first drawing of the moon is crude even by the standards of what one can see with the naked eye. The map clearly requires a telescopic view, but what evidence is there to suggest that the drawing was made at an eyepiece at all?

    I think the little squiggles you see on the terminator, right about dead center, are what tell you it’s a sketch of a telescopic view. To the naked eye, you wouldn’t be able to see the uneven shadows of the terminator crossing over mountains and valleys. But maybe I misunderstood your comment.

  16. sean hogge

    I, too, disagree with the implication that Galileo purposefully or intentionally mocked the Church. Galileo was rather distraught and quite upset that at his trial, the Church believed him to be a heretic. His mental and physical health soon deteriorated immediately following, and with the exception of one small rebound, he was never quite the same.

    The “intentional” mockery might be construed from his used of Simplicio in his “Dialogues” (which I don’t believe was published in his lifetime) and his other works which flagrantly attacked Aristotle’s description of the heavens. However, he actually sought permission from the church before publishing such works. Hardly the act of a rebel or gainsayer.

    He seemed more hurt, confused and frustrated by what transpired with the Church, the home of many of his friends, the benefactor of some of his wealth, amd the home of his (arguably favorite) daughter.

  17. Kurt Kohler

    I’m curious what the numbers on Harriot’s full moon map refer to. Is a key available somewhere? I couldn’t find it on the RAS site. Although perhaps if I was “bona fide media”…

  18. Nigel Depledge

    Nice post, Phil.

    I’m surprised, however, that you didn’t use the phrase “self-promotion has its place” as another opportunity to link to a certain book on Amazon…


  19. Sundance

    Opinions seem to differ on how much of a jerk Galileo was. The Sleepwalkers, by Arthur Koestler, certainly paints a very bad picture of him as arrogant, secretive, self-promoting and rude, not only to the pope, but also to other scientists like Kepler. If Koestler’s account is accurate Galileo went out of his way to ensure that other people couldn’t make equivalent discoveries, and publicly dismissed other people’s results to create the impression that he was the only one who’d discovered anything interesting.

    Caveat; The Sleepwalkers is a rather old book now, and the research upon which it is based may be badly out-of-date.

    But speaking of Kepler, I think we should remember what he achieved as well. Sadly he seems to often be viewed as a second-rate Newton, who invented three laws of planetary motion and had some whacky ideas about Platonic solids, but did little else, while we applaud the observational achievements of Galileo (and others like him and Harriot). But at a time when it was believed that different physical laws applied in different regions of the Universe, Kepler recognised that his laws of planetary motion (formulated by studying Mars) could be observationally tested by looking at the moons of Jupiter. In doing so he laid the foundations of the idea that all bodies gravitate, not just the Earth, and all bodies obey a set of _universal_ physical laws. He explicitly stated that “astronomy is a part of physics”. He defended his mother against accusations of witchcraft and was one of the first people to write a science fiction novel, to explain new scientific discoveries to a lay audience. If he was alive today he’d have a blog, extolling the wonders of the cosmos and debunking cranks.

  20. I don’t think that Galileo intentionally tried to mock the Pope (who was indeed his friend) or the Church. He did, however, fail to successfully navigate the politics of the Church at the time by making a couple crucial mistakes. The Pope, for example, was angry that Galileo never told him about the 1616 injunction that prohibited Galileo from holding or defending the heliocentric worldview. He thought that his book circumscribed this by making it a dialog, but it was clear from reading it which side he came down on. Not only that, but he included the Pope’s favorite argument against heliocentricism in the mouth of the dim-witted Aristotelian, Simplico, at the very in the of the book. Errors in judgment, to be sure, but that doesn’t make him a jerk. Overly confident, perhaps.

  21. Wildride

    Galileo was definitely bloodminded when dealing with the church over this issue but that was probably due to his previous ones. He’d already dealt with them stifling scientific learning simply on the basis that it conflicted with their world view. As he got older, he simply became less willing to tolerate their oppression.

  22. It’s reminiscent of the Newton/Liebnitz thing with calculus — if the Brits had published there would be no controversy. But Galileo, as Pieter Kok mentions above, didn’t just draw pictures, he figured things out and then brought the story to the people. I don’t think this discovery really lessens his reputation in the least.

  23. I have read 60 books about Galileo and one about Harriot. Many of the books about Galileo mention Harriot as well.

    I find it truly astonishing at the number of various opinions held by intelligent people about who Galileo was and what he did.

  24. Thanks, Phil. I’ve always wondered about why if the telescope had already been around and was introduced to Galileo he was was always credited as the first person to say “Hey! Let’s look at the moon!”

    I’m sure we’ll never know who the very first person who looked at the moon through a magnifying lens was, but they might not have realized they were the first.

  25. kuhnigget

    You also have to remember that when telescopes were first being introduced to the various courts of Europe one of the selling points was that you could look through them (backwards, to us) and view a “pixie world” in miniature.

    I suspect the very idea of there being anything worth looking at in the sky was just as big a leap as the act itself.

  26. ColinB

    “He went way out of his way to insult the Pope and the Church, and was pretty much a huge jerk about it. The Church at the time was not exactly the picture of acceptance and tolerance, but I think even Mahatma Gandhi would have poked Galileo in the eye after being around him for a few minutes.”

    I don’t want to come off as a church sympathizer, but doesn’t this sound a bit like a certain cracker dissing, squid fetishist we all admire so? :-)

  27. Davidlpf

    E pur si mouve. Another part of the Galileo legend but no matter how you phrased the Earth was not the center of the universe it was going to cause ripples back then. At the time Bruno asked if the stars might have planets around them and get a really hot foot for it(and the rest of his body).

  28. justcorbly

    Harriot was an interesting guy who played a significant role in England’s first attempts to colonize North America. Employed at the time by Walter Raleigh, he joined an expedition to North American in 1585, where he visited the islands off the North Carolina, learned some Algonquian, and, in 1588, authored what is likely the first serious study of native Americans and their environment.

  29. Mike Noren

    For what it’s worth, compare that first map Harriot drew, with the one Galileo drew in december the same year:
    That’s FOUR YEARS before Harriots more convincing map.

    Frankly, I still consider Galileo to have been the first to draw a moon map.

  30. KC

    I agree with Phil re: the jerk comment. Galileo was pretty arrogant if you read his writings (Starry Messenger etc.). I have little love of the Catholic Church (and neither IIRC does Phil) but Galileo certainly shares some of the blame for the situation. At the very least I think most scholars would agree that he failed “to successfully navigate the politics of the Church” as James put it above.

  31. Tim McCormley

    Believe it or not, the Catholic Church at that time was very supportive of Science, in general. They weren’t “liberal minded” by any stretch, but they certainly appreciated the value of reason and scientific research.

    The point that Phil makes (and I agree wholeheartedly) is that Galileo went out of his way to pull the Pope’s nose after he promised to steer clear of the controversy when he wrote his book. (The controversy being that the reconciliation of the heliocentric theory and Catholic dogma.)

    As an example, one of the principle characters in the “Dialogue” is named “Simplicio.” Simplicio was the one that advocated the “Earth centered theory.” It was an obvious (to the Pope, anyway) insult aimed directly at the Church, if not the Pope himself.

    To quote a fictional character, “It was like telling Al Capone that you don’t like the color of his tie.”

    So Galileo got called out on the carpet. Then he got all noble, and ended up with a much more severe punishment, than if he had just said he was sorry. Unfortunately, IIRC, by the time the book was published, saying “sorry” meant recanting his belief in the heliocentric theory.


  32. Bill Nettles

    Malcolm Longair’s take on Galileo is interesting. He considers that Galileo knew of Kepler’s elliptical orbits but in …Two World Systems as the character Salviatus, clung to the concept of CIRCULAR orbits. Ah, tradition.

  33. Troy

    Taking on the church is one of Galileo’s merits. The Roman Catholic church, as a power that stifled free thought, Galileo was the victim here. I suppose being friends with the pope probably saved his life.

  34. Nemo

    But what you have to understand that one reason we celebrate Galileo’s contributions is because Galileo was very good at self-promotion. He published his drawings, while Harriot did not.

    I don’t see that as an issue of self-promotion. If it’s not published, it’s of no value to the rest of humanity.

  35. Phil Plait: “Read the history of Galileo and the Church.”

    There has been written quite a lot about Galileo and the Church, so you can probably find texts that advocate either point. His Dialogo was certainly provocative (as pointed out above), and we know that he stood by his convictions and refused to recant. But isn’t that of huge importance to science? In fact, isn’t exposing attacks on science one of the main points of this very blog?

    He may very well have been arrogant, I don’t know. But calling him a “huge jerk” seems too judgemental to me.

  36. Joseph Lavelle

    I enjoyed all the comments about Galileo, and used such a telescope as he devised. Rome did apologise for their mistake, recently. Saint Francis of Assisi, Italy’s male patron saint wrote a poem where he called the moon sister and the sun brother. In his day it was possible to see the sky at night, big and bright as it was, deep in the heart of Texas. Despite it being forty years since a foot was set on the moon, what have we learned? I would suggest that we are hoping to use a moon base to attack someone or country. Remember that we are all loonies at heart but capable of the worst atrocities.

  37. Sir Eccles

    Is it just me, or looking at that first picture does it not look like Jesus standing on a grassy knoll dropping his pants at JFK’s presidential cavalcade as it drives past?

  38. I’m guessing that Galileo just published in the journal much quicker.

    If you read Timothy’s Ferris’s Coming of Age in the Milky Way, he catalogues how much of a jerk Galileo was in re: the Church. Kepler was outraged when his antics got De Revolutionibus banned, if I recall correctly.

  39. Nice nod of the head to Harriot Phil, thank you however there are two technical historical points in your explanation that are wrong.

    1) As somebody has already pointed out the first historical record of the telescope, which concerns Lippershey is 25th September 1608 (I was at the 400th birthday bash in Middelburg last September!). So Harriot’s first moon map is only 9 months later.

    2) Galileo’s telescopes were not better than Harriot’s they were about equal, if anything Harriot’s were superior, so that is not the reason that Harriot quit observing.

    Pieter Kok: There are no two ways, the evidence is very clear Galileo was very insulting to the Pope and got kicked for it.

  40. It was an obvious (to the Pope, anyway) insult aimed directly at the Church, if not the Pope himself.

    Er, not really. The Pope didn’t even realize he was being insulted (from the biographies I’ve heard), if he was actually intetionally being insulted at all, until the Inquisition went to him and started whispering in his ear about it. And, as has been mentioned already, Galileo got the book past the censorship office before publication. Only later did the Inquisition claim it was problematic.

    And, in fact, the Inquisition had been pursuing Galileo for quite a while before they finally were able to convince the Pope to let them charge him. There’s copious evidence of irregularities in their case file on him, for example (places where it had been taken apart and new pages inserted to make them look as if they were older documents than they were, etc.), to convince most people that it didn’t really matter much what Galileo did, they were going to get him by hook or by crook.

    Which isn’t to say Galileo wasn’t an egotist and wasn’t far too undiplomatic for his own good. But he always respected the Church and was, according to his own statements, trying to save it from eventual embarrassment when they were proved to be holding to a wrong world-view.

  41. Phil, after reading _Galileo’s Daughter_ by Dava Sobel, I have a different perspective on Galileo and his relationship with the Catholic Church. I’m convinced that he thought his dialogue didn’t violate the spirit of the 1616 injunction. He knew he had to do some literary tap dance, hence the dialogue. What the clash between the man against the Church really highlights is Galileo’s faith that God wasn’t afraid of Truth while the same couldn’t be said for the Church. He may have been mocking certain beliefs held by the Church, intentionally even, but characterizing him as “a jerk” seems too strong. I’d start with “foolish” and go from there.

    I enjoyed _Galileo’s Daughter_ immensely and posted a review here:

  42. quasidog

    You learn something new everyday. Top bit Phil.

  43. poke

    Galileo is primarily remembered for his contributions to physics and the scientific method, I think, while his contributions to astronomy are usually seen as extension and promotion. If you read Galileo’s writings I think he sounds a lot like “one of us.” For example, after he published his observations of the moon he spent a lot of time defending himself against philosophers who claimed he must be wrong because the moon is a perfect sphere (according to the Aristotelism of the time), and his arguments are almost word for word the same sort of arguments rationalists still use. (Note that we’re also accused of being jerks.) The philosophers first claimed that Galileo’s observations were simply wrong and spent their time trying to discredit his life and work. Later, after more people came to support Galileo’s conclusions, they turned to arguing that the moon may have observable features but could still be surrounded in an imperceptible but perfectly spherical crystalline structure. Galileo argued that if it’s imperceptible then it, too, could be covered in mountains and craters and then the philosophers would have to propose another sphere around that, and so on, ad infinitum. This is pretty much exactly how we argue with supernaturalists now (to no end). It’s also a good illustration of the fact that philosophers were opponents of science from the very start and modern science was never a development or extension of philosophy. Galileo and other scientists came primarily from a practical background. Galileo’s early work involved solving engineering problems and this led to his interest in mechanics, optics, etc.

  44. “It’s also a good illustration of the fact that philosophers were opponents of science from the very start and modern science was never a development or extension of philosophy.”

    That is a generalization and an oversimplification.

  45. Paul S.

    Some philosophers were opposed to Galileo, others supported him. Remember that the physical sciences were actually considered a variety of philosophy up until the 19th century – that’s why what we call scientists were called “natural philosophers” until the mid 19th century.

  46. Mike Noren

    It is beyond me why people are defending the church on this, and by slandering Galileo at that. It irks me because it seems the motivation for slandering Galileo simply is to defend the church’s reputation.

    The “insults” Galileo flung at the pope were statements like these:
    “I do not feel obliged to believe that same God who endowed us with sense, reason, and intellect had intended for us to forgo their use.”
    “I think that in the discussion of natural problems we ought to begin not with the Scriptures, but with experiments, and demonstrations.”
    “It vexes me when they would constrain science by the authority of the Scriptures, and yet do not consider themselves bound to answer reason and experiment.”

    Those WERE highly controversial and insulting to the church of the day. Fightin’ words. That doesn’t make Galileo wrong or obnoxious for saying them. He was opinionated, principled, AND RIGHT.

    His “unpleasantness” was that he persisted in saying these things, even when told to shut up. He recanted only when the torturer showed him the various pliers, irons and hooks which would be used to torture him into submission.

    As for Harriots map: it was never published and has no historical importance. Not only that, but it’s hardly even a doodle. At best it is a curiosity.

    Meanwhile, Galileo published an actual map, better than EITHER of Harriots, and changed western society forever.

    It annoys me to no end when people for ideological reasons belittle Galileos achievements and enormous importance.

  47. Jim Craig

    Harriot’s biggest error was one we often hear in academia today: publish or perish. His maps were largely unknown until recently. The better of the two above was found pressed between the pages of a book by another author.

    Harriot did a lot of amazing work in mathematics and optics but failed to let anyone outside his immediate circle of friends know about it. Consequently, today we celebrate Galileo’s discovery of the four largest moons of Jupiter while James Harriot is largely forgotten by history (here in North Carolina we remember him because he was the ship scientist who traveled with Sir Walter Raleigh and one of the first to try to translate Native American languages).

    So while I’d never disparage Harriot’s work, it didn’t do him or the rest of the world very much good. At least Galileo, with his gift for self promotion, allowed the rest of us in on the secret.

  48. JupiterIsBig

    Not publishing definitely limits your historical significance.
    Take New Zealand’s Richard Pearse versus the Wright Brothers.

    “11 May 1903 – Pearse took off along the side of the Opihi River, turned left to fly over the 30′ tall river-bank, then turned right to fly parallel to the middle of the river. After flying nearly 1,000 yards, his engine began to overheat and lost power, thus forcing a landing in the almost dry riverbed. ”
    There may have been others ….


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