Babylonian astronomy in the context of MUL.APIN

Astronomy is a natural science that studies celestial objects and the phenomena that occur in the cosmos. It uses mathematics, physics, and chemistry to explain their origin and their overall evolution. Objects of interest include planets, moons, stars, nebulae, galaxies, meteoroids, asteroids, and comets. Relevant phenomena include supernova explosions, gamma ray bursts, quasars, blazars, pulsars, and cosmic microwave background radiation. More generally, astronomy studies everything that originates beyond Earth's atmosphere. Cosmology is the branch of astronomy that studies the universe as a whole.

Astronomy is one of the oldest natural sciences. The early civilizations in recorded history made methodical observations of the night sky. These include the Egyptians, Babylonians, Greeks, Indians, Chinese, Maya, and many ancient indigenous peoples of the Americas. In the past, astronomy included disciplines as diverse as astrometry, celestial navigation, observational astronomy, and the making of calendars.

Ancient Greek astronomy is the astronomy written in the Greek language during classical antiquity. Greek astronomy is understood to include the Ancient Greek, Hellenistic, Greco-Roman, and late antique eras. Ancient Greek astronomy can be divided into three phases, with Classical Greek astronomy being practiced during the 5th and 4th centuries BC, Hellenistic astronomy from the 3rd century BC until the formation of the Roman Empire in the late 1st century BC, and Greco-Roman astronomy continuing the tradition in the Roman world. During the Hellenistic era and onwards, Greek astronomy expanded beyond the geographic region of Greece as the Greek language had become the language of scholarship throughout the Hellenistic world, in large part delimited by the boundaries of the Macedonian Empire established by Alexander the Great. The most prominent and influential practitioner of Greek astronomy was Ptolemy, whose Almagest shaped astronomical thinking until the modern era. Most of the most prominent constellations known today are taken from Greek astronomy, albeit via the terminology they took on in Latin.

Greek astronomy was influenced heavily by Babylonian astronomy, as well as Egyptian astronomy to a lesser degree. In later centuries, Greek-language astronomical works were translated into other languages, enabling their further spread. Most notably, Arabic translations of these works benefitted astronomers and mathematicians throughout the Muslim world during the Middle Ages.

The zodiac is a belt-shaped region of the sky that extends approximately 8° north and south celestial latitude of the ecliptic – the apparent path of the Sun across the celestial sphere over the course of the year. Within this zodiac belt appear the Moon and the brightest planets, along their orbital planes. The zodiac is divided along the ecliptic into 12 equal parts, called "signs", each occupying 30° of celestial longitude. These signs roughly correspond to the astronomical constellations with the following modern names: Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, and Pisces.

The signs have been used to determine the time of the year by identifying each sign with the days of the year the Sun is in the respective sign. In Western astrology, and formerly astronomy, the time of each sign is associated with different attributes. The zodiacal system and its angular measurement in 360 sexagesimal degree (°) originated with Babylonian astronomy during the 1st millennium BC, probably during the Achaemenid Empire. It was communicated into Greek astronomy by the 2nd century BC, as well as into developing the Hindu zodiac. Due to the precession of the equinoxes, the time of year that the Sun is in a given constellation has changed since Babylonian times, and the point of March equinox has moved from Aries into Pisces.

Nabu (Akkadian: 𒀭𒀝, romanized: Nabû, Jewish Babylonian Aramaic: נְבוֹ‏, romanized: Nəḇo) is the Babylonian patron god of literacy, scribes, wisdom, and the rational arts. He is associated with the classical planet Mercury in Babylonian astronomy.

Berossus (/bəˈrɒsəs/) or Berosus (/bəˈroʊsəs/; Ancient Greek: Βηρωσσός, romanized: Bērōssos; possibly derived from Late Babylonian Akkadian: 𒁹𒀭𒂗𒉺𒇻𒋙𒉡, romanized: Bēl-reʾû-šunu, lit. 'Bel is his shepherd') was an early-3rd-century BCE Hellenistic-era Babylonian writer, priest of Bel Marduk, and astronomer who wrote in the Koine Greek language.

His original works, including the Babyloniaca (Ancient Greek: Βαβυλωνιακά), are lost, but fragments survive in some quotations, largely in the writings of the fourth-century CE early Christian writer Eusebius.

Iraq, a country located in West Asia, largely coincides with the ancient region of Mesopotamia, often referred to as the cradle of civilization. The history of Mesopotamia extends back to the Lower Paleolithic period, with significant developments continuing through the establishment of the Caliphate in the late 7th century AD, after which the region became known as Iraq. Within its borders lies the ancient land of Sumer, which emerged between 6000 and 5000 BC during the Neolithic Ubaid period. Sumer is recognized as the world's earliest civilization, marking the beginning of urban development, written language, and monumental architecture. Iraq's territory also includes the heartlands of the Akkadian, Neo-Sumerian, Babylonian, Neo-Assyrian, and Neo-Babylonian empires, which dominated Mesopotamia and much of the Ancient Near East during the Bronze and Iron Ages.

Iraq was a center of innovation in antiquity, producing early written languages, literary works, and significant advancements in astronomy, mathematics, law, and philosophy. This era of indigenous rule ended in 539 BC when the Neo-Babylonian Empire was conquered by the Achaemenid Empire under Cyrus the Great, who declared himself the "King of Babylon." The city of Babylon, the ancient seat of Babylonian power, became one of the key capitals of the Achaemenid Empire.

Babylonian astronomy collated earlier observations and divinations into sets of Babylonian star catalogues, during and after the Kassite rule over Babylonia. These star catalogues, written in cuneiform script, contained lists of constellations, individual stars, and planets. The constellations were probably collected from various other sources. The earliest catalogue, Three Stars Each, mentions stars of Akkad, of Amurru, of Elam and others.Various sources have theorized a Sumerian origin for these Babylonian constellations, but an Elamite origin has also been proposed. A connection to the star symbology of Kassite kudurru border stones has also been claimed, but whether such kudurrus really represented constellations and astronomical information aside from the use of the symbols remains unclear.

Star catalogues after Three Stars Each include the MUL.APIN list named after the first Babylonian constellation APIN, "the Plough", which is the current Triangulum constellation plus Gamma Andromedae. It lists, among others, 17 or 18 constellations in the zodiac. Later catalogues reduce the zodiacal set of constellations to 12, which were borrowed by the Egyptians and the Greeks, still surviving among the modern constellations.