If you have ever been to a traditional Latin Mass, you no doubt noticed that the altar servers make a big ceremony out of carrying the big book to the left side of the altar before the priest reads the Gospel. Is there some kind of symbolism going on with left and right? Are we supposed to think of those who stand at our Lord’s left and right at the judgment?
It turns out that the ceremony has nothing to do with left and right.  According to the rubrics, the priest reads the Gospel toward the north. In fact, what we usually see at a Low Mass or High Mass is a compressed version of the full ceremony of a Solemn Mass, where the subdeacon chants the Epistle on the right side and the deacon, after a procession with candles, chants the Gospel on the left side of the Church, facing directly toward the north. We’re all aware that churches are traditionally oriented toward the east, and east is important because the rising sun symbolizes Christ coming. But in liturgical terms, north is also important because, by a long tradition, the north represents the dark realm where the light of the gospel has not yet shone. We read the Gospel toward the north to represent the Church’s mission to the unevangelized.
In fact, after the Council of Trent permission was given for churches to be oriented not just toward the east but in other directions, if needed for some reason—any direction, in fact, except to the north. No church shall point in the direction of evil.
Where would such an idea come from? Some biblical texts come to mind. For example, Jeremiah 1:14, “From the north shall an evil break forth upon all the inhabitants of the land, for behold, I will call together all the families of the kingdoms of the north.” There are many such passages, because Israel’s great enemies, Assyria and Babylon, were north of the promised land. In Ezekiel 8:3, an idol was set up in the Temple in the inner court that faces north. Such scattered hints congeal into a solid tradition with time, so that, for example, Hildegard of Bingen’s mystical vision Scivias speaks of the north with horror:
Ach, ach! In the north, I have been attacked and plundered with the eyes and with the joy of knowledge, with my garment completely torn. I was removed from my rightful place, and I was led into another place which lacked any beauty and honor where I was subjected to the worst servitude. 
At first glance, it all seems a bit arbitrary. Scripture is not uniformly negative about the north. The east’s importance rests on the obvious and glorious fact of the sun’s path, while north’s infamy seems to rest on a bit of ancient geography and the dim memory of a sour moment in Israel’s history.
To go deeper, we have to question our assumptions. What exactly does “north” mean?
The ancients knew nothing of magnetic north, of course. They found the north by looking to the heavens: to everyone before the advent of electric lights, it was obvious that all the constellations in the night sky rotate around the north star. As the sun’s rising is the overwhelming fact of day, the north star’s constant and central presence is the obvious fact of night, second to the moon in brilliance but second to none in reliability. But what in fact is the north star?
It turns out that the earth’s rotation is not entirely steady. It wobbles a bit, a phenomenon called “precession”. So over the course of about 26,000 years, a line drawn through the earth’s axis describes a complete circle in the sky, and along the way various stars become the “north star,” i.e., the star currently aligned with the earth’s axis.  Today, the north star is Polaris, but as recently as 4,000 years ago the north star was Thuban, located in an entirely different constellation.  Egyptian temples were specially built so that Thuban would be visible through a door on one particular side.  If you go out at night and find Thuban in the sky, you are looking at the north star as Abraham would have known it when God called him in about 2000 BC.
This is more than a bit of trivia. While our names for the constellations are Latin translations of Greek names, the Greeks got their traditional constellations from civilizations before them. If we map out the traditional constellations, they rotate around Thuban: in other words, the constellations familiar to us today were “discovered” at least 4,000 years ago.  That’s far too old for the Greeks to have invented them.
So who invented them? The traditional constellations give us no names for anything within 36 degrees of the South Pole, so whoever first invented them must not have been able to see anything that far south. If we know exactly how far south their view of the night sky extended, then we can deduce how far north they were: they were located at a latitude of about 36 degrees north. This is too far south to be Greece—and the Greeks were already out of the running on the basis of chronology. On the other hand, it’s too far north to be Egypt, that most ancient of civilizations. What great people existed more than 4,000 years ago and was located at a latitude of 36 degrees north?
The answer is simple: the great civilizations of the fertile crescent, beginning with the Sumerians and continuing with the Babylonians. And in fact we do know that the civilizations of the fertile crescent maintained a lively interest in astronomy—hence the “magi from the east”.
To sum up: we assume that north means toward Polaris, but the heavens as we know them were mapped out more than 4,000 years ago in Sumeria, when Thuban was the north star.
So what is Thuban? It’s name is simply the Arabic word for the constellation of which it forms a part: Draco. 
For the ancient Babylonians, our closest witnesses to the original Sumerian tradition, the constellation Draco was Tiamat, the sea.  As the story goes, Tiamat was the mother of all the gods, but then turned on the gods in the form of a serpent and attempted to eat them all.  Marduk slew her with a bolt of lightening and then carved up her body to make the earth and the sky. It would be easy to show that the creation account in Genesis 1 specifically wishes to counter this Babylonian creation myth—note for example how God divides up the ocean to make everything. Either this myth or the Canaanite version of it is adapted to Israel’s God in many passages of the Old Testament, for example:
Psalm 74:13, “Thou didst divide the sea by thy might; thou didst break the heads of the dragons on the waters.”
Isaiah 27:1, “In that day the LORD with his hard and great and strong sword will punish Leviathan the fleeing serpent, Leviathan the twisting serpent, and he will slay the dragon that is in the sea.”
Isaiah 51:9, “Was it not thou that didst cut Rahab in pieces, that didst pierce the dragon?”
Job 26:12-13, “By his power he stilled the sea; by his understanding he smote Rahab. By his wind the heavens were made fair; his hand pierced the fleeing serpent.”
For the ancient Greeks, Draco had a parallel role.  As Tiamat turned on Marduk and company, so the Greeks told of the time the Titans attempted to overthrow the gods of Olympus. At one point in the battle, a dragon attacked Athena, but she slew it and threw it up into the sky where it wrapped around the earth’s axis to form the constellation we see today.
The Realm of Darkness
We are now close to answering our original question, because scholars today generally agree that the creation myth in which God combats the dragon stands in the background of Revelation 12, where the dragon is directly identified as “that ancient serpent, who is called the Devil and Satan” (Rev 12:9). 
According to an ancient Jewish interpretation (see, e.g., 2Enoch 29:1), Isaiah 14:12-15 already associates Satan with the northern stars:
How you are fallen from heaven, O Lucifer, son of Dawn! How you are cut down to the ground, you who laid the nations low! You said in your heart, “I will ascend to heaven; above the stars of God I will set my throne on high; I will sit on the mount of assembly in the far north; I will ascend above the heights of the clouds, I will make myself like the Most High.” But you are brought down to Sheol, to the depths of the Pit.
Notice that, if we take this text as referring to Satan, he is depicted as a star that rises up against God, he is associated with the stars in the north, and he is defeated in a pattern reminiscent of the myth of Tiamat or the Titans.
Revelation 12:1-9 also describes Satan’s rebellion and defeat, but there the image of the dragon is explicit and the association with stars even clearer:
And a great portent appeared in heaven, a woman clothed with the sun, with the moon under her feet, and on her head a crown of twelve stars; she was with child and she cried out in her pangs of birth, in anguish for delivery. And another portent appeared in heaven; behold, a great red dragon, with seven heads and ten horns, and seven diadems upon his heads. His tail swept down a third of the stars of heaven, and cast them to the earth. And the dragon stood before the woman who was about to bear a child, that he might devour her child when she brought it forth; she brought forth a male child, one who is to rule all the nations with a rod of iron, but her child was caught up to God and to his throne, and the woman fled into the wilderness, where she has a place prepared by God, in which to be nourished for one thousand two hundred and sixty days. Now war arose in heaven, Michael and his angels fighting against the dragon; and the dragon and his angels fought, but they were defeated and there was no longer any place for them in heaven. And the great dragon was thrown down, that ancient serpent, who is called the Devil and Satan, the deceiver of the whole world—he was thrown down to the earth, and his angels were thrown down with him.
The stars cast down to the earth seem to be the angels who fell with Satan. That being the case, Satan himself would seem to be a star or group of stars. Interestingly, the word semeion or “portent” used to describe Satan can also refer to a constellation of stars. 
Given the trail of evidence I have laid out associating Satan with the north and with stars and with the dragon of ancient mythology, I don’t think it too much of a leap to see Satan as represented by the constellation Draco.
If I may push the evidence further (perhaps to the breaking point): notice that the constellation Draco, long and snaky, twines around and between the constellations of Ursa Maior and Ursa Minor, the Big Bear and the Little Bear. If Draco fell to the earth, he would bring with him first and foremost a great beast and a little beast, which happen to be the next two characters we meet in Revelation 12.
The Gospel of Light
This post has mostly been suggestive speculation, but the picture that seems to emerge is this:
For the ancient Sumerians, “north” meant toward the dragon, who ruled the sky when all was dark, but around the time when God called Abraham out of Sumeria, Thuban lost his place as the center of the night sky. This dragon was understood as the foe of the gods, and in Scripture was eventually seen as the foe of God—Satan, that ancient serpent. The reign of the dragon has been overthrown by the resurrection of Christ, the rising sun.
It makes all the sense in the world that we would face the rising sun when we worship. It makes all the sense in the world that we would not face north, toward Draco, when we worship. And although it might surprise our human instincts, it makes perfect sense in God’s infinite mercy that we would proclaim the Gospel to the north, to all those under Satan’s dominion.
On a recent camping trip, I stumbled out of our camper at 4:30 AM to check out the constellations. We were far from any electric lights, and at 8,000 feet high there was almost no humidity to dim the stars, which were dazzlingly bright. When I looked east—a great sign appeared in the heavens! I saw the morning star, and it was the biggest thing short of the moon that I have ever seen in the sky. I couldn’t believe my eyes. I stumbled back to the camper and shook my wife out of bed: “You’ve got to come see this. You’ll never believe it! I’ve—I’ve seen Mary.”
 Everything about liturgy and the Council of Trent in this blog post comes from a letter from my friend Peter Kwasniewski, who over the years has collected notes from various learned tomes relating to “north” in the liturgy.
 Hildegaard of Bingen, Scivias, trans. Bruce Hozeski (Santa Fe: Bear & Company, Inc., 1986), 42.
 The content of this paragraph is from Mark R. Chartrand, National Audobon Society Field Guide to the Night Sky (New York: Alfred A. Knopf, 1991), 51-52.
 Ibid., 53 and 512.
 Ibid., 512.
 The information in the remainder of this section is taken from The Teaching Company’s course, Our Night Sky, taught by Prof. Edward M. Murphy. The material can be found in the first lecture, beginning at 12 minutes and 30 seconds. The shape of the argument is easy to follow, although I’m taking the specific conclusion about “36 degrees north” on faith from Prof. Murphy.
 National Audobon Society Field Guide to the Night Sky, 512.
 Ibid., 511.
 My summary of the story is based on the translation in Victor H. Matthews and Don C. Benjamin, Old Testament Parallels: Laws and Stories from the Ancient Near East (New York: Paulist, 1997), 10-18.
 National Audobon Society Field Guide to the Night Sky, 511.
 That the chaos battle myth stands behind Revelation 12 is a commonplace in scholarship. One can look in almost any contemporary more technical commentary.
 I accessed this in an electronic form, so I can’t give a proper footnote. But it’s the semeion entry in Lewis and Short’s huge Greek lexicon.