Ides of March 15, 44 BCE, Astronomically Signified the Full Moon Phase

Summary: The Ides of March 15, 44 BCE, astronomically signified the onset of the full moon phase, according to ancient Roman and Julian calendars.

laureate head of Julius Caesar with winter's waxing crescent moon; obverse of coin, minted February-March 44 BCE by moneyer Lucius Aemilius Buca: Classical Numismatic Group, Inc. http://www.cngcoins.com, CC BY SA 3.0 Unported, via Wikimedia Commons

The Ides of March 15, 44 BCE, astronomically signified the appearance of the full moon phase, according to three-part monthly divisions in ancient Roman and Julian calendars.

The assassination of Roman general and statesman Gaius Julius Caesar (July 12, 100 BCE-March 15, 44 BCE) took place in the afternoon of March 15, known as the Ides of March, in 44 BCE. Caesar's senatorial assassins fatally stabbed him in the Curia of Pompey (Latin: Curia Pompeia), a meeting hall at the entrance to the Theater of Pompey (Latin: Theatrum Pompeii) in the southern sector of Rome's Campus Martius ("Field of Mars").

The ancient lunar Roman calendar, in effect during the Roman Kingdom (Latin: Regnum Romanum; 753 BCE-509 BCE) and from 509 BCE to 46 BCE during the Roman Republic (Latin: Res publica Romana), and the solar Julian Calendar, in effect as of Jan. 1, 45 BCE, recognized three-part divisions of each month. The kalends opened each month as the first day, with succeeding emphases on the nones and ides, according to JSTOR Daily author Liz Tracey in "Beware the Ides of March. (But Why?)," posted March 15, 2022.

Kalends, each month's first marker day, etymologizes from Latin's kalendae, “first day of a Roman month." Kalendae occurs as an archaic variant of calendae, case and number inflection of calandus, "which is to be called or announced solemnly." The Kalends announced the appearance of each month's new moon.

Nones, each month's second critical point, sources from Latin's nonae, "ninth days," feminine plural of nonus, "the ninth." Ancient Rome's inclusive counting placed the nones on the seventh day in 31-day months (March, May, July, October) and on the fifth day in all other months. The nones referenced each month's first quarter lunar phase.

Ides, each month's third emphasis, derives from Latin feminine plural noun idus, from Latin iduare and possibly Etruscan itu-, "to divide." Ancient Rome's inclusive counting assigned the Ides to 15th day in 31-day months and the 13th day in all other months. The Ides proclaimed the sighting of each month's full moon.

(left) laureate Julius Caesar with winter's waxing crescent moon and (right) Venus, Julian lineage's ancestral goddess, with winged victory and sceptre; obverse and reverse of coin, minted February-March 44 BCE by moneyer Lucius Aemilius Buca: Classical Numismatic Group, Inc. http://www.cngcoins.com, CC BY SA 3.0 Unported, via Wikimedia Commons

The full moon occurred March 15, 44 BCE, at 10:01 Coordinated Universal Time (UTC), according to California-born computer programmer John Walker in his table of "New and Full Moons" in the Lunar Perigee and Apogee Calculator section of his Fourmilab Switzerland website. Central European Time (CET), the modern time zone observed by Italy's capital, retrojects the time of 44 BCE's Ides of March full moon to 11:01 a.m., one hour later (UTC+1), according to the Time and Date website.

March 1, 44 BCE heralded the month's opening new moon. The March kalends new moon occurred at 11:23 UTC (12:23 p.m. CET).

The first quarter phase took over March 8. The March nones quarter moon commenced at 11:43 UTC (12:43 p.m. CET).

The third, or last, quarter, which was not announced in ancient Rome, appeared March 23. It started at 07:52 UTC (8:52 a.m. CET).

A center-to-center distance of 383,422 kilometers separated Earth from its satellite at the moment of fullness. The distance equates to 60.1 Earth radii, according to Walker's earthly equatorial radius conversion.

In March 44 BCE, perigee (Ancient Greek: περί, perí, “near” + γῆ, gê, “Earth”) was achieved on March 9 at 0:42 UTC (1:42 a.m. CET). The month's closest moon-to-Earth distance measured 369,954 kilometers. Thus, the lunar distance on March 15, 44 BCE was only 13,468 kilometers less close than the closest distance credited to the month's first quarter phase.

In March 44 BCE, apogee (Ancient Greek: ἀπόγειον, apógeion, “away from Earth”) occurred on March 22 at 13:37 UTC (2:37 p.m. CET). The month's farthest moon-to-Earth distance measured 404,154 kilometers. Thus, the lunar distance on March 15, 44 BCE was only 20,732 less distant than the farthest distance acquired by the month's transitioning waning gibbous-to-third quarter phase.

The appearance of the moon on the night before his assassination concerned Julius Caesar, according to Greek biographer Plutarch (46 BCE-ca. 122 CE) in his Lives of the Noble Greeks and Romans, commonly known as Parallel Lives. "After this, as he was in bed with his wife, all the doors and windows of the house flew open together; he was startled at the noise, and the light which broke into the room, and sat up in bed, where by the moonshine he perceived Calpurnia fast asleep, but heard her utter in her dream some indistinct words and inarticulate groans," according to the translation (volume two, page 576), published in 1683, by first Poet Laureate of England John Dryden (Aug. 19 August [O.S. Aug. 9], 1631-May 12 [O.S. May 1], 1700).

Ides of March 15, 44 BCE, full moon, at 10:01 Coordinated Universal Time (UTC), viewed from 383,422 kilometers above Curia of Pompey, place of Julius Caesar's assassination (41 degrees 53 minutes 42 seconds North, 12 degrees 28 minutes 26.4 seconds East: John Walker, via Fourmilab Switzerland

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

laureate head of Julius Caesar with winter's waxing crescent moon; obverse of coin, minted February-March 44 BCE by moneyer Lucius Aemilius Buca: Classical Numismatic Group, Inc. http://www.cngcoins.com, CC BY SA 3.0 Unported, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:RSC_0022.jpg; via NASA APOD @ https://apod.nasa.gov/apod/ap160229.html

(left) laureate Julius Caesar with winter's waxing crescent moon and (right) Venus, Julian lineage's ancestral goddess, with winged victory and sceptre; obverse and reverse of coin, minted February-March 44 BCE by moneyer Lucius Aemilius Buca: Classical Numismatic Group, Inc. http://www.cngcoins.com, CC BY SA 3.0 Unported, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:RSC_0022.jpg; via NASA APOD @ https://apod.nasa.gov/apod/ap160229.html

Ides of March 15, 44 BCE, full moon, at 10:01 Coordinated Universal Time (UTC), viewed from 383,422 kilometers above Curia of Pompey, place of Julius Caesar's assassination (41 degrees 53 minutes 42 seconds North, 12 degrees 28 minutes 26.4 seconds East: John Walker, via Fourmilab Switzerland @ https://www.fourmilab.ch/cgi-bin/Earth?imgsize=320&opt=-l&lat=41.8949&ns=North&lon=12.474&ew=East&alt=383422&img=LRO_100m.evif&date=1&utc=-44-03-15+10:01:00

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