The Manger in the Sky

I

The word Luke chose

3 times in one chapter, and the second time it is the sign.

Luke uses φάτνη at 2:7, 2:12, and 2:16. At 2:12 the angel gives a complete identifying σημεῖον: a baby wrapped in cloths and lying in a manger. The manger is part of the sign, not the whole sign by itself. Spine

In the Greek sky, the same word named a place. AratusAratus of Soli (c. 315–240 BCE), author of the Phaenomena, the most widely read astronomical poem of the ancient world. Paul quotes its fifth line at the Areopagus (Acts 17:28). The Manger and the Donkeys appear in its weather-sign section, c. lines 892–899. tells the reader to watch the Φάτνη, a small mist in Cancer, with a faint star on either side of it he calls the Ὄνοι, the Donkeys. When the Manger dims while the Donkeys still shine, he says, rain is coming. Today the mist is PraesepePraesepe (M44, the Beehive Cluster): an open star cluster in Cancer about 577 light-years away, roughly 1,000 member stars. To the naked eye it is a faint misty patch about 1.5° across. Greek name Φάτνη, “the Manger”; Latin Praesepe, “the stall” or “crib.” and the Donkeys are the AselliThe Aselli, “the little donkeys”: γ Cancri (Asellus Borealis, magnitude 4.7) and δ Cancri (Asellus Australis, magnitude 3.9), the two stars flanking Praesepe. Aratus calls them the Ὄνοι, “the Donkeys.”. Spine

The link to Luke is closer than a shared vocabulary. At Athens, Paul quotes the fifth line of the same poem: “for we are also his offspring” (Acts 17:28), and it is Luke who records the speech. The author of Luke 2 worked in a literary world where φάτνη also named a light in the heavens. That makes the double sense available to his first readers; it does not prove he intended it. Scaffold

II

The donkeys at their lord’s manger

3 Scriptures stand where the sky puts 2 stars beside a mist.

The CatasterismiCatasterismi (“Placings among the Stars”), a Hellenistic handbook attributed to Eratosthenes, giving the myths behind each constellation. Chapter 11 (Cancer) explains the two Donkeys set beside the Manger. (chapter 11) explains the Donkeys as the mounts of Dionysus, set beside the Manger. That is the pagan story. Isaiah had put a donkey at its lord’s manger centuries before, and the Septuagint renders that manger with the same Greek word. Scaffold

III

Reckoning the evening

From the spring equinox of 7 BCE to the dusk of 31 May 7 BCE, every date computed in the Julian calendarJulian calendar: the Roman calendar in force in the 1st century. All dates in this exhibit are Julian. Astronomers number 7 BCE as year −6 (there is no year 0 in BCE/CE counting, but there is in astronomical counting)..

The Sun set at 18:54 local mean time; nautical dusk fell at 19:55. Spine

Mercury deserves its own line. It reached its greatest evening elongationElongation: the angle between a planet and the Sun as seen from Earth. Mercury never strays more than about 28° from the Sun, so it can only be seen low in twilight., 25.2° from the Sun, on 27 May 7 BCE, so this was the best week of its apparition: magnitude 0.8, 9° above the horizon, beside Pollux. On 31 May it stood less than 1° inside the western border of Cancer, between the Twins and the Manger. It was not near El Nath: it passed 3.3° from that star around 4 May, when it was only 14° from the Sun and lost in its glare. Spine

IV

The cradle under Venus

The evening of 30 May 7 BCE, from sunset to moonset. Drag the time to watch the twilight deepen.

This was the first evening the new crescent could be seen. At sunset (18:53 local mean time) the Moon was about 38 hours old, 2.7% lit, 17.9° from the Sun, and it stayed up for about 95 minutes. Its horns lay 13° to 24° from level through the evening: a cradle, low in the west-northwest. In the chart the Moon is drawn about 3 times its true size and the crescent thickened so it can be seen. Spine

Venus stood above it and to the left, 14.4° to 15.2° from the Moon, and 1.3° from the Manger. Spine

The moment you are looking for is a window, not an instant. The geometry hardly changes all evening: Venus stays 17° to 20° off the cradle’s axis, drifting slowly closer to it until moonset at 20:29. It never stands plumb over the Moon; in azimuth it stays 8° to 9° to the left. The crescent would first stand out against the twilight around 19:15, and the best view runs from about 19:20 to 19:50, before the Moon sinks into the horizon haze. The slider opens at 20:03, with the cradle just above the hills; drag back toward 19:20 for the surer sighting. Spine

The messenger in the middle. Mercury stood at the midpoint of the line from the cradle to Venus: 47% to 50% of the way along it, and only 2.2° to 2.4° to one side, for the whole time the crescent was up. The cradle on the ground, the evening star above, and the messenger between them. Spine

It came 1 day after Jupiter and Saturn first met, on the first evening of a new month by the crescent reckoningThe crescent reckoning: the conventional view that each month began at the first sighting of the new crescent in the evening twilight.: the first cradle of the month under the evening star, at the Manger. Conviction

V

A multitude of the heavenly host

Luke’s vocabulary holds both senses of the phrase. Here the host is angels. In Acts 7:42, in Stephen’s speech, στρατιᾷ τοῦ οὐρανοῦ is the stars themselves, following the Septuagint of Jeremiah 8:2 and Zephaniah 1:5. Spine

The Manger fits the phrase closely. To the naked eye Praesepe is a single faint glow. The first telescope turned on it, in 1610Sidereus Nuncius (“Starry Messenger”), 1610: Galileo’s first telescopic report. He wrote that the nebula called Praesepe is not one star but a mass of more than 40 small stars., found more than 40 stars; the modern count is about 1,000. Looked into, the manger is a multitude. Wink

VI

What the evening is, and what it is not

Venus at the Manger recurs. Through the octaeterisOctaeteris: the 8-year cycle in which Venus returns to almost the same place among the stars on almost the same calendar date (5 synodic periods of Venus ≈ 8 solar years, to within about 2 days). The Moon’s phases also nearly repeat on it (99 lunations ≈ 8 years), but drift about 1.5 days per cycle., Venus reached Praesepe on 1 June 15 BCE, 31 May 7 BCE, 31 May 2 CE, and 30 May 10 CE, each time within 0.8°. The crescent beside it does not repeat so faithfully: in those neighbouring cycles the Moon stood 20° to 52° away. Spine

The week does not recur easily. A triple conjunction of Jupiter and Saturn comes on the order of once in 139 years. That its first meeting fell 2 days before Venus and the new crescent entered the Manger joins a rare event to a recurring one. Scaffold

No one saw the Manger itself that night. Praesepe at magnitude 3.7, 33° from the Sun in twilight, was almost certainly invisible. What a watcher could see was the brightest planet and the new Moon, standing where the Manger is. Spine

Reading it. Luke gives a sign whose name is written in the sky; the Scriptures put donkeys at their lord’s manger and a child between two living creatures; and in the week the kings first met, the evening star and the new crescent came to the Manger. Conviction

VII

From evening star to morning star

The light that stood over the cradle in 7 BCE rose before the dawn at Nazareth in 25 CE.

In 7 BCE Venus was the evening star. It stood over the cradle on 30 May and in the Manger on 31 May, and it held the evening sky until it passed the Sun on 5 November 7 BCE. Spine

30 years later it was the evening star again as the ministry opened. At the baptism placement, 7 September 24 CE, it stood 25° east of the Sun; at Cana, about 20–22 October 24 CE, 35°. “Mine hour is not yet come” (John 2:4). Spine The dates are the house harmony of The 45 Days from Baptism to Cana. Conviction

Then it crossed. The spring equinox of 25 CE fell on 22 March at 17:27 UT. About 30 hours later, on 24 March, Venus reached inferior conjunctionInferior conjunction: Venus passing between Earth and Sun. Before it, Venus is the evening star; after it, the morning star. It happens every 584 days., passing 7° north of the Sun. It was last seen in the evening around 19–20 March and first seen before dawn around 25–26 March. Spine

Nisan 1. The first full moon after that equinox came on 1 April at 20:21 UT, 22:42 at Nazareth, so by the full-moon reckoningThe full-moon reckoning held in this corpus: Nisan 1 is the first day after the first full moon following the spring equinox, and each later month opens the day after its full moon. Nisan 1 was 2 April 25 CE. That morning Venus rose at 04:51, almost exactly due east, at magnitude −4.2. In the west at the same hour the full moon was setting, with Jupiter 1.8° beside it. Spine

The sabbath at Nazareth. The first sabbath after that full moon was Saturday 7 April 25 CE, Nisan 6. This exhibit places the Nazareth reading (Luke 4:16–21) on that day. Conviction Venus rose at 04:30, magnitude −4.3, 21.5° from the Sun, and stood 9° up at civil dawn with Mercury below it. Saturn, Shabbtai, the sabbath star, rose with the Sun, 10.5° from it and unseen. Spine

Mercury rose 2° from the point among the stars where Jupiter and Saturn metThe point among the stars where Jupiter and Saturn met in longitude on 29 May 7 BCE, near 09:00 UT, in Pisces. Stars move so slowly that the point is the same place on the sky 31 years later. on 29 May 7 BCE, and Venus 6.5° from it. The messenger and the morning star came up in the east from the place where the kings had met at the birth. Wink

The scroll handed to him was Isaiah; the passage he read is Isaiah 61, and the chapter before it opens, “Arise, shine; for thy light is come … and kings to the brightness of thy rising” (Isaiah 60:1–3). Wink Luke calls the coming Christ ἀνατολήἈνατολή: “rising,” “the east,” “dawn.” Luke 1:78 calls the coming Christ ἀνατολὴ ἐξ ὕψους, “the dayspring from on high.” The LXX uses the same word for the promised Branch (Zechariah 3:8; 6:12)., the dayspring (Luke 1:78). Peter writes, “until the day dawn, and the day star arise in your hearts,” and his word is φωσφόροςΦωσφόρος, “light-bringer”: the ordinary Greek name for Venus as the morning star (Latin Lucifer). Peter uses the word in 2 Peter 1:19., the morning star (2 Peter 1:19). The Lord names himself “the bright and morning star” (Revelation 22:16). Scaffold

Base rate: Venus changes from evening to morning star every 584 days, and through the octaeteris a spring crossing like this one returns every 8 years, about 17, 25, and 33 CE. Venus and Mercury pass through Pisces most springs. The crossing itself is common; its placement at the opening of the ministry belongs to the house chronology.

VIII

Check the sky yourself

Nothing here belongs to the author. These steps put the same evening on your own screen.