ASTRONOMY.

By: Morris Jastrow, Jr., Peter Jensen, Marcus Jastrow, Ludwig Blau, Richard Gottheil, Joseph Jacobs

—Biblical Data:

Biblical Astronomy, in the broad sense, includes the views taken in the books of the Bible of the position of the earth in the universe, the designation of the stars, planets, fixed stars, and the views held regarding them. The material for the subject, except so far as the earth is concerned, is very meager, dependence for the most part having to be placed on ambiguous references chiefly in the poetical sections. In the present article the stars, planets, and fixed stars in general are dealt with. (For the earth, sun, and moon, see Cosmogony, Sun, Moon.) The sky, the abode of the stars, is described as a "raḳia'" (, a plate); that is, a rigid, broad, solid plate possessing a certain thickness. According to Gen. i. 6, this raḳia' was set in the midst of the waters, and it divided the waters above from those beneath. God "made" it of matter already existing at the time of Creation; that is, He did not "create" it at that time. The raḳia' representing the sky in Ezek. i. 22 resembled ice; therefore it is quite possible that the author of Genesis, like Ezekiel, regarded the sky as being composed of solidified water or ice. Such a sky, being transparent, would permit the stars, which are located above its vault, to be seen through it.

The Four Elements in Genesis.

The heavenly bodies, according to Gen. i. 16, were also made (not created) from existing material, after light had come into existence. They were certainly made of the material of light, just as the vault of the sky was made out of water-material, and the human soul from air (Gen. ii. 7), and all things living upon earth from earth (Gen. i. 24). All these were made of the four elements, light (or fire), water, air, and earth; only those creatures which subsist in air and water—that is, in other elements than those of which they are composed—were created; while man, the image of God, although living on earth and being of the earth, was "created and made" (Gen. i. 26, 27; but see ii. 7).

Stars the Hosts of Heaven.

The stars were supposed to be living creatures. If the difficult passage (Judges v. 20) may be regarded as other than a poetical figure, the stars "walk on the way"; they "come out" in the morning, and "go in" at night. By a miracle, sun and moon are made to stand suddenly still (Josh. x. 12). They fight from their courses like warriors on the march (Judges ib.); the poet perhaps thinks of falling stars. In later times the stars are spoken of as "the hosts of heaven." This conception is accurately paralleled among the Assyrians, kinsmen of the Hebrews, who likewise conceive of the stars as soldiers serving the god of heaven, Anu, and probably also the somewhat similar god Ninib, whose abode was the planet Saturn. Eabani (?) is compared in the Gilgamesh epic (tab. i. col. 5, 28, 40; see Schrader, "K. B." vi. i. 130 et seq.) with an army of Anu and falling stars or (tab. i. cols. 11, 33, 35; see ib. p. 120) with the army of Anu and Ninib. The stars stand in God's presence, to the right and the left of His throne (I. K. xxii. 19; II Chron. xviii. 18); they serve Him (Neh. ix. 6; Ps. ciii. 21), and praise Him (Ps. ciii. 21), cxlviii. 2). Like the kings of earth, they may be consigned by God's judgment to the nether world (Isa. xxiv. 21 et seq.); and God will in future execute judgment among them as among the nations of earth (Isa. xxxiv. 4 et seq.). Reverence is offered to them as living creatures, even in later times (Jer. viii. 2), and quite naturally upon the housetops (Jer. xix. 13, xxxii. 29; Zeph. i. 5), in the same manner as the Assyrians worshiped the sun (Gilgamesh epic, iii. 2, 7 (15); Schrader, "K. B." vi. 1, 146).

"Captain of Army."

At the head of this starry host stands a "captain of the army" (, Josh. v. 14; Dan. viii. 11); according to the passage in Daniel, he was the star highest in altitude as well. By this designation probably Saturn was intended, the farthest removed from earth and therefore the highest in the heavens,and which is held by the Assyrians to be the "bellwether" of the flock. This starry army belongs to Yhwh; hence the frequent expression "Yhwh of hosts" or "God of hosts" () indicates that He is the actual leader of the heavenly array. According to a later view, however (Zech. iv. 2, 10), the seven planets are evidently termed the "seven eyes of God" (Smend, "Alttestamentliche Religionsgesch." p. 343, note), just as the planet Saturn was the eye of Anu, lord of heaven among the Babylonians. It would appear, therefore, that they were no longer considered independent beings, and of course the other stars likewise. This passage has probably no reference whatever to the seven-armed candlestick of the Temple; and it has no connection with what the Hebrews may or may not have conceived concerning the planets.

Individual Stars.

As regards the individual stars, current opinion holds to-day that four to six, perhaps seven, are named in the Old Testament. Such are: "Kesîl" (, Isa. xiii. 10; Amos v. 8; Job ix. 9, xxxviii., 31), understood generally to be Orion; "Kimah" (, Amos l.c.; Job l.c.), identical with Sirius or the Pleiades; "'Ash" or "'Ayish" (, Job ix. 9, xxxviii. 32), possibly the Great Bear, possibly the Hyades or Pleiades; "Mazzarot" (, Job xxxviii. 32), either the Pleiades or Hyades, or possibly the Northern and Southern Crown. Another is mentioned, "Ḥadre Teman" (, Job ix. 9) but it is doubtful whether or not a constellation is meant by this at all; see G. Hoffmann, in "Zeitschr. Alttestamentliche Wissenschaft," ii. 107, who holds that Kesîl is Orion; Kimah, Sirius; 'Ayish, the Hyades; Mazzarot, the Pleiades; and that is to be amended to read ("chambers of the Twins," Gemini).

According to this view, all the fixed stars and constellations mentioned in the Old Testament would lie in one region of the stellar hemisphere; and according to Stern (Geiger's "Jüd. Zeit." iii. 258), these, and these only, are mentioned because they serve to indicate the seasons of the calendar. These identifications, however, admit of no positive proof; for a disconnected tradition can hardly be considered a demonstration. The only case in which anything approaching proof can be adduced is that of 'Ash or 'Ayish by means of the Talmudic word , "yuta" (mentioned with this star and perhaps etymologically related to it)—in Syriac, ; in Arabic, ("rain")—which would agree with the idea of the constellation of the Hyades, the "rain-stars." It should then be punctuated to read "'ayush" (Hoffmann).

"Mazzarot," in Job xxxviii. 32, may perhaps, by comparison with Job xxxvii. 9, where "mezarim" () is paralleled by "Ḧeder" (, "chamber"), be explained as identical with "Ḥadre Teman" (chambers of the south) (Job ix. 9) or etymologically referred to the Assyrian "massartu" (Babylonian "mazzartu"), a place where something is watched. But it is just as likely to be, as tradition already has it, a variation of "mazzalot" (, II Kings xxiii. 5)—a word also of uncertain meaning, varying as its explanations do between "planets," "constellations of the zodiac," and "stations of the moon." If the word were indisputably of Assyro-Babylonian origin and related to "manzaltu" or "mazaltu," either of the two latter significations would probably be the correct one, seeing that "manzaltu" means "stand" or "station," is also applied to stars, and, like its synonym, "manzazu," denotes probably some one or other of the zodiacal constellations.

"Kesîl," remarkably enough, is found in the plural in Isa. xiii. 10, where "the stars of heaven and its [or their] kesîlim" are spoken of. This is commonly translated "their Orions," and is explained as meaning "their larger constellations"; but the plural of such a proper name is very hard to understand. One would hardly speak of "the Siriuses" or "the Greater Bears" of the heavens. It is probably to be understood as a generic term, not a proper name at all, and to be translated "stars" instead of "Orions." A corollary herefrom would be that "'Ayish" and "Kimah" would then also be generic names and not proper ones, a supposition which their exclusive occurrence in the singular would not disprove (compare the generic singulars in Isa. xxx. 6). And when God, in Job xxxviii. 31 et seq., is said to bind Kimah, open Kesîl, and lead 'Ayish, these proper names may well in reality mean nothing more than planets, meteors, or comets, and thus the word "Kesîl" (fool) be a not inappropriate name for the vagrant comet, the roving planet, or the headlong meteor. It is true, however, that difficulties would arise when considering the "children of 'Ayish" and various other points in connection with these names; and altogether this remarkable plural of Kesîl in Isaiah, with its usual translation, must remain a bone of contention.

That "naḦash bariaḦ" (, "flying serpent"), Isa. xxvii. 1 and Job xxvi. 13, denotes a constellation, as has been claimed, rests upon no evidence.

Planets.

Of planets, as far as ascertainable with any degree of certainty, only two are mentioned in the Old Testament: Saturn, called by his Assyrian name "Kévan" () in Amos v. 26; and "Meleket ha-Shamayim" (), "the queen of heaven," Jer. vii. 18, xliv. 17, 25, etc. That the latter means Venus is shown by the cakes which are said to have been baked for her. Among the Assyro-Babylonians the cakeofferings were called "the bread of Ishtar" (Venus).

Helel, Son of the Morning.

It is usually claimed that by the word "Helel" , "son of the morning," in Isa. xiv. 12, the morning star, or, more correctly, one of the two morning stars, is meant; and the analogy with ("to glitter") seems to favor the view. Closely considered, however, there is little foundation for the supposition, since Isaiah gives no intimation whatever that Helel is a star (Gunkel, "Schöpfung und Chaos," pp. 132 et seq.).

The supposition that "Gad" () in Isa. lxv. 11 means "Jupiter," the god of Fortune, and that "Meni" (), in the same verse, means "Venus" (if these readings be correct), rests upon mere hypothesis.

If it were not that the late-Hebrew name "Ẓedeḳ" (="justice") for "Jupiter" betrays, not an Assyro-Babylonian origin, but rather a late Jewish one—for among the Assyro-Babylonians Saturn is the star of justice—it might be accepted as an earlyJewish name for that planet; but to endeavor to connect this with the Old Testament proper names "Meichizedek" and "Adonizedek" is, to say the least, hazardous.

The Old Testament contains no more than the preceding concerning Hebrew Astronomy. Of Hebrew astrology before the Babylonian exile, it contains not a word; for the passage Isa. xlvii. 13, wherein astrologers are evidently meant by "the astrologers, the star-gazers, the monthly prognosticators," is regarded by most scholars as post-exilic. This may perhaps indicate that the ancient Hebrews possessed no astrology; at all events, what is known of the astrology of the later Hebrews shows Assyro-Babylonian influence, as is illustrated by the fact that Mercury, for instance, is called "the star," just as the Assyro-Babylonians designate him simply as "the planet."

J. Jr. P. J.Ancient Conception of Astronomy. —In the Talmud:

The study of the universe as a whole was, like all other sciences in olden times, held in closest connection with religion, and was cultivated in the interest of the latter. The starworld was to the heathen an object of worship, but not to the Jews, whether national or Hellenized. With this reverence there was connected a superstition that the stars determined the destiny of man. The computation of time also depends upon a knowledge of the heavenly bodies; and this again was closely connected with religion. It is obvious, therefore, that the Astronomy of the Talmudists could not be an independent science any more than that of the Babylonians, the Egyptians, the Greeks, or of all other nations of antiquity or of the medieval ages: it was a department of knowledge belonging to theology. Only those data which are purely astronomical are dealt with here; for the rest see Astrology, Calendar, and Worship, Idol. Nor can those cosmological speculations which were prevalent among all nations of antiquity be discussed in this article.

The facts handed down form, however, only a fraction of the astronomical knowledge of the Talmudists; for in their academies they touched upon scientific problems only so far as they related to religious questions, and exercised great reserve regarding their stellar investigations, so as not to betray the secrets of the festival calendar, an important privilege of the house of the Palestinian patriarch and of his tribunal. For these two reasons the following account will naturally give only an inadequate idea of the knowledge of Astronomy among the Jews during the first centuries of the common era. Furthermore, these fragments do not emanate from one homogeneous system, as they are the accumulations of at least four centuries, and are traceable to various authors, Palestinian and Babylonian, among whom some were inclined to mysticism.

Astronomy a Religious Study.

The high value of astronomical knowledge is already demonstrated by the astronomical section of the Book of Enoch (about 72-80), as well as by such sayings as those of Eleazar Ḥisma (about 100), a profound mathematician, who could "count the drops in the ocean" (Hor. 10a), and who declared that "ability to compute the solstice and the calendar is the 'dessert [auxiliaries] of wisdom '" (Ab. iii. 18). Among the sciences that Johanan ben Zakkai mastered was a knowledge of the solstices and the calendar; i.e., the ability to compute the course of the sun and the moon (Suk. 28a). Later writers declare that "to him who can compute the course of the sun and the revolution of the planets and neglects to do so, may be applied the words of the prophet (Isa. v. 12), 'They regard not the work of the Lord, neither consider the operation of his hands.'" To pay attention to the course of the sun and to the revolution of the planets is a religious injunction; for such is the import of the words (Deut. iv. 6), "This is your wisdom and your understanding in the sight of the nations" (Shab. 75a).

No Scientific Discoveries in Palestine.

Despite the general importance and religious significance attached to Astronomy in the Holy Land, no scientific discoveries were made there. Astronomical observatories and instruments are nowhere mentioned, unless among the latter are included a chart illustrating the various phases of the moon (R. H. ii. 8), and a sort of telescope for the calculation of air-line distances ("meẓofot," Yer. 'Er. v. 22d; "shefoferet," Bab. 'Er. 43b). The starry heavens of Palestine interested the Jews, indeed, as creations of God, as means to determine the holidays; but for a better knowledge of them the Jews were undoubtedly indebted to the Babylonians and their Hellenic pupils, as evidenced by the foreign term "gemaṭria," used to designate the computation of the calendar. Possibly this word represents a transposition of γραμματεία= "arithmetic, mathematics" (Sachs, "Beiträge," ii. 74)—"a sister science of astronomy from the earliest times, but destined as the mathematical element to obtain adequate importance only in later periods" (Pauly-Wissowa, "Realencyklopädie der Classischen Alterthumswissenschaft," 1831, ii.). Most of the observations of a scientific nature were transmitted by Samuel (250), who attended the schools of the Babylonians, and who claimed to possess as exact a knowledge of the heavenly regions as of the streets of his own city Nehardea. Certain rules must nevertheless have existed; for the patriarch Rabban Gamaliel (about 100), who applied the above-mentioned lunar tablets and telescope, relied for authority upon such as had been transmitted by his paternal ancestors (Yer. R. H. ii. 58b; Bab. R. H. 25a).

Conceptions of Heaven and Earth.

As in the Bible, so also in the Talmud, heaven and earth designate the two borders of the universe. The former is a hollow sphere covering the earth. It consists, according to one authority, of a strong and firm plate two or three fingers in thickness, always lustrous and never tarnishing. Another tannaitic authority estimates the diameter of this plate as one-sixth of the sun's diurnal journey; whileanother, a Babylonian, estimates it at 1,000 parasangs. According to others, the diameter of the firmament is equal to the distance covered in 50 or 500 years; and this is true also of the earth and the large sea ("Tehom") upon which it rests (Yer. Ber. i. 2c; Targ. Yer. Gen. i. 6). The distance of the firmament from the earth is a journey of 500 years—a distance equivalent to the diameter of the firmament, through which the sun must saw its way in order to become visible (Yer. Ber. i. 2c, bot.; Pes. 94a). The firmament, according to some, consists of fire and water, and, according to others, of water only; while the stars consist of fire (Yer. R. H. ii. 58a). East and west are at least as far removed from each other as is the firmament from the earth (Tamid. 32a). Heaven and earth "kiss each other" at the horizon; and between the water above and that below there are but two or three fingerbreadths (Gen. R. ii. 4; Tosef., Ḥag. ii. 5). The earth rests upon water and is encompassed by it. According to other conceptions the earth is supported by one, seven, or twelve pillars. These rest upon water, the water upon mountains, the mountains upon the wind, and the wind upon the storm (Ḥag. 12b; Yer. Ḥag. ii. 77a). The nations of antiquity generally believed that the earth was a disk floating on water. There is also mentioned the terrestrial globe, "kaddur," though it may also be translated as "disk." When Alexander the Great attempted to ascend to heaven he rose even higher and higher, until the earth appeared as a globe and the sea as a tray (Yer. 'Ab. Zarah iii. 42c, bot.). The earth is divided into three parts, viz., habitable land, desert, and sea.

It was assumed that our present earth was preceded by many others which were not good in the eyes of the Creator, who traverses in all 18,000 worlds, and for this reason is frequently styled "Lord of the Worlds" (Gen. R. iii. 7, ix. 2; Midr. Teh. xxxiv.). The ocean also is mentioned in the Talmud, and the whole world is said to drink of its waters (Ta'an. 9b). According to mystic speculation there are seven heavens, the first of which is called "velum" (curtain); the second, "firmament," etc. (Ḥag. 12b). Whether these worlds are similar to ours is not stated. The correct impression concerning the infinitude of the starry host is expressed in the following sentence of R. Simeon b. Laḳish (about 250): "There are twelve mazzalot [signs of the zodiac], each having thirty armies; each army, thirty camps [ = castra]; each camp, thirty legions [compare Matt. xxvi. 53]; each legion, thirty cohorts; each cohort, thirty corps [compare Krauss, "Lehnwörter," s.v. ]; and each corps has 365,000 myriads of stars entrusted to it" (Ber. 32b).

Motions of the Heavenly Bodies.

The Talmud subscribes, as do all astronomers before the time of Copernicus, to the geocentric worldconception, according to which the stars move about the earth. The conceptions of this motion were various. Aristotle believes that the stars have no motion of their own, being firmly attached to circles of rotation; and he further ascribes to every circle containing a star a sphere of motion whose center is the earth (Pauly-Wissowa, "Realencyklopädie der Classischen Alterthumswissenschaft," 1841, ii.). Perhaps the wonderful Baraita PesaḦim 94b gives expression to this idea in the following: "The learned of Israel say, 'The sphere stands firm, and the planets revolve'; the learned of the nations say, 'The sphere moves, and the planets stand firm.' The learned of Israel say, 'The sun moves by day beneath the firmament, and by night above the firmament'; the learned of the nations say, 'The sun moves by day beneath the firmament, and by night beneath the earth.'" The patriarch Judah I. (about 200) believed that in the first instance the Jewish, and in the second the non-Jewish, conception was correct. The sun travels in four directions. During Nisan, Iyyar, and Siwan (spring) it travels in the south, in order to melt the snow; during Tammuz, Ab, and Elul (summer), directly above the earth, in order to ripen the fruit; during Tishri, Ḥeshwan, and Kislew, above the sea, in order to absorb the waters; and in Ṭebet, Shebaṭ, and Adar, over the desert, in order that the grain may not dry up and wither (ib.).

The sun has 365 windows through which it emerges; 182 in the east, 182 in the west, and 1 in the middle, the place of its first entrance. The course described by it in a year is traversed by the moon in 30 days. The solar year is longer by 11 days than the lunar year (Yer. R. H. ii. 58a). The sun completes its course in 12 months; Jupiter, in 12 years; Saturn, in 30 years; Venus and Mars, in 480 years (Gen. R. x. 4); however, an objection is raised here (in a gloss) against the last-mentioned number. King Antoninus asked the patriarch why the sun rises in the east and sets in the west. At the time of the Deluge it traveled in the opposite direction (Sanh. 91b, 108b). Every 28 years it returns to its original point of departure, and on Tuesday evening of the spring solstice it is in opposition with Saturn, although Plato maintained that the sun and planets never return to the place whence they started. This is the cycle of 28 years (Ber. 59b); the moon-cycle of 19 years may have been meant in the Targ. Yer. Gen. i. 14.

Six Seasons.

The four solstices (the Teḳufot of Nisan, Tammuz, Tishri, and Ṭebet) are often mentioned as determining the seasons of the year; and there are occasional references to the rising-place of the sun ('Er. 56a). Sometimes six seasons of the year are mentioned (Gen. R. xxxiv. 11), and reference is often made to the receptacle of the sun (ναρθήκιον), by means of which the heat of the orb is mitigated (Gen. R. vi. 6, and elsewhere). The revolutions of the moon were undoubtedly known; for "Israel computes by the moon, the other nations by the sun" (Suk. 29a, and elsewhere). God expressly prohibits the revealing of the secrets of chronology (Ket. 112a). Samuel sent to R. Johanan a list of the leap-years for sixty years, which the latter did not regard as exhibiting any remarkable mathematical skill. (Ḥul. 95b). "The moon begins to shine on the 1st of the month; its light increases until the 15th, when the disk [ (δίσκοσ)] is full; from the 15th to the 30th it wanes; and on the 30th it is invisible" (Ex. R. xv. 26).

Seven Planets.

From the names of the seven planets were derived the names of the days of the week; and each daywas consecrated to the particular planet that ruled during the early hours of the morning. The Talmudists were familiar with the planets and their characteristics (see Astrology); but only the week-days were counted, while the Sabbath had a name of its own. The names of the seven planets are: (1) "Shabbetai," Saturn; (2) "Ẓedeḳ," Jupiter; (3) "Maadim," Mars; (4) "Ḥammah," the sun; (5) "Kokebet" or "Nogah," "Kokab-Nogah," Venus; (6) "Kokab," Mercury; (7) "Lebanah," the moon. According to the first letter of each of their names, they are called "SheẒaM ḤeNKaL" (Shab. 129b, 156a; Pesiḳ. R. xx.; Pirḳe R. El. vi.). The worship of Venus is mentioned (Pesiḳ. R. xxxi., ed. Friedmann, p. 143a), and warning is given not to confuse it with the dawn (; Yer. Ber. i. 2c).

The Zodiac.

The twelve constellations of the zodiac are: Aries ("Ṭaleh"), Taurus ("Shor"), Gemini ("Teomim"), Cancer ("Sarṭon"), Leo ("Ari"), Virgo ("Betulah"), Libra ("Moznayim"), Scorpio ("'Aḳrab), Sagittarius, Archer ("Ḳasshat"), Capricornus ("Gedi"), Aquarius ("Deli"), and Pisces ("Dagim"). According to the first letter of each, they are collectively called "ṬeSHeT," "SaAB," "Ma'AḲ," "GeDaD" (Pesiḳ. R. l.c., and Pirḳe R. El. l.c.; Rashi on B. M. 106b, and elsewhere). The first three are in the east, the second three in the south, the third three in the west, and the last three in the north; and all are attendant on the sun. According to one conception, Aries, Leo, and Sagittarius face northward; Taurus, Virgo, and Capricornus westward; Gemini, Libra, and Aquarius southward; and Cancer, Scorpio, and Pisces eastward (Yalḳ., Ex. 418; Kings 185). According to the tannaitic view, Taurus ("'Eglah") is in the north and the Scorpion in the south ('Er. 56a; Pes. 94a). [Some read "'Agalah" (Wagon = Charles's Wain), see Tos. to Pes. l.c.] Each constellation rules for one month; viz.; Aries in Nisan (March), Taurus in Iyyar (April), etc. (Pesiḳ. R. xxvii., ed. Friedmann, p. 133b; Pesiḳ. R. K. xiii. 116a). That the zodiacal circles were generally known is evident from the frequency of their interpretation in sermons and from their liturgical application in post-Talmudic times. An allusion to Aquarius is found also in a Babylonian incantation (Giṭ. 69a).

Other Stars and Comets.

The Milky Way is called "Fire-Stream," a name borrowed from Daniel vii. 10 ("Nehar di-nur"), where it may possibly have had the same signification. The statement is also made that the sting of Scorpio may be seen lying in the Milky Way (Ḥag. 13b; Ex. R. xv. 6, ; Ber. 58b). Samuel said: "We have it as a tradition that no comet ever passed across the face of Orion ["Kesil"]; for if this should happen the earth would be destroyed." When his hearers objected to this statement, saying, "Yet we see that this occurs," Samuel replied: "It only appears so; for the comet passes either above or below the star. Possibly also its radiance passes, but not its body." Again, Samuel says: "But for the warmth of Orion, the earth could not exist, because of the frigidity of Scorpio; furthermore, Orion lies near Taurus, with which the warm season begins (Yer. Ber. ix. 13c; Bab. Ber. 58b). The comet, because of its tail, is called "kokba de-shabbiṭ." (rodstar). Joshua b. Hananiah, the famous teacher of the Law (about 100), declared that a star appears once every seventy years and leads mariners astray; hence they should at such time lay in a larger store of provisions (Hor. 10a). Rapoport endeavors to prove that the path of Halley's comet had been computed by a wise rabbi (Epistle to Slonimski in "Toledot ha-Shamayim," Warsaw, 1838). Samuel said: "I know all the paths of heaven, but nothing of the nature of the comet."

The following Biblical names of constellations are mentioned and explained: . Pleiades [a cluster of] about a hundred stars, and for the muchdisputed , its equally obscure Aramaic equivalent (MS. M. ), Syriac , is given (Ber. 58b). The following two sagas also have reference to natural phenomena. When R. Jacob died, stars were seen by day; when R. Ḥiyya died, stones of fire fell from heaven (M. Ḳ. 25b). The latter may possibly be a reference to meteors.

J. Sr. L. B.—In Post-Talmudic Times:

With the revival of Greek science which took place in Islam, Jews were intimately connected, and the "Almagest" is said to have been translated by Sahal ibn Tabari as early as 800, while one of the earliest independent students of Astronomy among the Arabs was Mashallah (754-873?). Jews seem to have been particularly concerned with the formation of astronomical tables of practical utility to astronomers. Sind ben Ali (about 830) was one of the principal contributors to the tables drawn up under the patronage of the Sultan Maimun. No less than twelve Jews were concerned in the Toledo tables, drawn up about 1080 under the influence of Aḥmad ibn Zaid, and the celebrated "Alfonsine Tables" were executed under the superintendence of Isaac ibn Sid, while Jews were equally concerned in the less-known tables of Pedro IV.

Isaac al-Ḥadib compiled astronomical tables from those of Al-Rakkam, Al-Battam, and Ibn al-Kammad. Joseph ibn Wakkar (1357) drew up tables of the period 720 (Heg.); while Mordecai Comtino and Mattathia Delacrut commented upon the Persian and Paris tables respectively; the latter were commented upon also by Farissol Botarel. Abraham ibn Ezra translated Al-Mattani's Canons of the Khowarezmi Tables, and in his introduction tells a remarkable story of a Jew in India who helped Jacob ben Tarik to translate the Indian astronomical tables according to the Indian cycle of 432,000 years. Other tables were compiled by Jacob ben Makir, Emanuel ben Jacob, Jacob ben David ben Yom-Ṭob Poel (1361), Solomon ben Elijah (from the Persian tables), and Abraham Zacuto of Salamanca (about 1515).

The earliest to treat of Astronomy in Hebrew on a systematic plan was Abraham bar Ḥiyya, who wrote at Marseilles, about 1134. Discussions on astronomical points, especially with regard to the spheres, and disputed points in calculating the calendar occur frequently in the works of Judah ha-Levi, Abraham ibn Ezra, and Maimonides, while a new system of Astronomy is contained in the "Warsof the Lord" ("Milḥamot Adonai") of Levi ben Gershon.

Jews were especially helpful in the progress of the science by their work as translators: Moses ibn Tibbon translated from the Arabic Jabir ben Aflah's acute criticisms of the Ptolemaic system, an anticipation of Copernicus, and thus brought them to the notice of Maimonides. Ibn al-Haitham's Arabic compendium of Astronomy was a particular favorite of Jewish astronomers; besides being translated into Spanish by Don Abraham Faquin, it was turned into Hebrew by Jacob ben Makir and Solomon ibn Pater Cohen and into Latin by Abraham de Balmes. Other translations from the Arabic were by Jacob Anatoli, Moses Galeno, and Kalonymus ben Kalonymus, who thus were the means of bringing the Greco-Arabic astronomers to the notice of western Europe. Jacob Anatoli, for example, translated into Hebrew both the "Almagest" and Averroes' compendium of it, and this Hebrew version was itself translated into Latin by J. Christmann. Other translators from the Hebrew into Latin were Abraham de Balmes and Kalonymus ben David of Naples, while David Kalonymus ben Jacob, Ephraim Mizraḥi, and Solomon Abigdor translated from the Latin into Hebrew. The well-known family of translators, the Ibn Tibbons, may be especially mentioned. In practical Astronomy Jewish work was even more effective. Jacob ben Makir (who is known also as Profiat Tibbon) appears to have been professor of Astronomy at Montpelier, about 1300, and to have invented a quadrant to serve as a substitute for the astrolabe. Levi ben Gershon was also the inventor of an astronomical instrument, and is often quoted with respect under the name of Leon de Bañolas. Bonet de Lattes also invented an astronomical ring. Abraham Zacuto ben Samuel was professor of Astronomy at Salamanca, and afterward astronomer-royal to Emanuel of Portugal, who had previously been advised by a Jewish astronomer, Rabbi Joseph Vecinho, a pupil of Abraham Zacuto, as to the project put before him by Columbus, who, in carrying it out, made use of Zacuto's "Almanac" and "Tables."

With the Renaissance, Jewish work in Astronomy lost in importance, as Europe could revert to the Greek astronomers without it. The chief name connected with the revival of astronomical studies on the Baltic is that of David Gans of Prague (d. 1613), who corresponded with Kepler, Tycho Brahe, and Regiomontanus; he was acquainted with the Copernican system, but preferred that of Ptolemy, while as late as 1714 David Nieto of London still stood out against the Copernican system. Altogether, in reviewing Jewish Astronomy in the Middle Ages, one can not claim that Jews themselves made many contributions to the science; but by making the Greco-Arabic Astronomy accessible to Europe, they aided in keeping the interest in the subject alive, and prepared the way for the revival of the science in the sixteenth century. On the practical side of the science, their chief contributions were of more value: almost all the tables used by astronomers and navigators were their work, while they introduced several improvements in astronomical instruments. See also Calendar.

The modern epoch of the science begins with a great Jewish name, that of Sir William Herschel (1738-1822), whose Jewish origin is acknowledged by his biographer. His systematic survey of the heavens, continued and completed by his son John, his catalogues of nebulæ and clusters, and his discovery of the planet Uranus, may be classed among the greatest exploits in the history of Astronomy. He also started the investigation into the constitution of the universe, determined the path of the sun toward the constellation Vega, and in innumerable ways started this science along the lines on which it developed up to the time of the discovery of spectrum analysis. He was assisted throughout his work by his sister Caroline Herschel (1750-1848). Since his time no very great Jewish name has been connected with the development of astronomical science, but no less than fourteen of the asteroids were located by H. Goldschmidt (1802-66)—at a time when the discovery of an asteroid was by no means so easy a task or so frequent an occurrence as it is nowadays—and W. Beer (1797-1850), the brother of Meyerbeer, was the first to draw an accurate map of the moon. Of contemporaries, the most distinguished is Moritz Loewy (b. 1833), director of the Paris Observatory, and the inventor of the coudé or elbow telescope, by which the stars may be observed without bending the neck back and without leaving the comfortable observatory.

The following list of Jewish astronomers of the Middle Ages, with the approximate periods of their activity, arranged in alphabetical order of first names, some of whom are mentioned elsewhere in this work, may be of service in drawing attention to the minuter details:

• Abraham de Balmes.
• Abraham ibn Ezra (1093-1168).
• Abraham bar Ḥiyya (1130).
• Abraham of Toledo (1278).
• Abraham Zacuto ben Samuel (16th cent.).
• Andruzagar ben Zadi Faruch.
• Augustinius Ricius (1521).
• Baruch Sklow (circa 1777).
• Baruch ben Solomon ben Joab (1457).
• Bianchino (15th cent.).
• Bonet de Lattes (1506).
• Caleb Afendopolo (15th cent.).
• David Gans (died 1613).
• David Kalonymus ben Jacob (1464).
• David ibn Nahmias.
• David Nieto (died 1728).
• Dayyan Ḥasan (972).
• Elia Misraḥi (died 1526).
• Emanuel ben Jacob (1346-65).
• Ephraim Mizraḥi.
• Farissol Moses Botarel (1465).
• Hananeel ben Ḥushiel (died 1020?).
• Ḥayyim Lisker (1612-36).
• Ḥayyim Vital Calabrese (died 1620).
• Isaac ben Aaron (1368).
• Isaac Abu al-Khair ben Samuel (1340).
• Isaac Albalia ben Baruch (1035-94).
• Isaac ibn al-Ḥadib (1370).
• Isaac Israeli ben Joseph (1310-30).
• Isaac ben Meir Spira.
• Isaac ben Moses Efodaeus, Proflat Duran (1392-1403).
• Isaac ibn Sid (1252).
• Israel Lyons (died 1775).
• Israel Samose (died 1772.)
• Jacob Anatoli (1232).
• Jacob Carsi (Jacob al-Corsono ben Abi Abraham Isaac, 1376).
• Jacob ben David ben Yom-Ṭob Poel (1361).
• Jacob ben Elia.
• Jacob ben Judah Cabret (1382).
• Jacob ben Makir, Proflat Tibbon (1289-1303).
• Jacob ben Samson (1123-42).
• Jacob ben Tarik (9th cent. ?).
• Jeremiah Cohen of Palermo (1486).
• Joseph ben Eleazar (14th cent.).
• Joseph ben Isaac ben Moses ibn Wakkar (about 1357).
• Joseph ben Israeli ben Isaac (died 1331).
• Joseph ibn Nahmias (1300-30).
• Joseph Parsi.
• Joseph Taytazak (about 1520).
• Judah Farissol (1499).
• Judah ha-Levi (1140).
• Judah ben Israeli (1339).
• Judah ben Moses Cohen (1256).
• Judah ben Rakufial (before 1130).
• Judah ben Samuel Shalom (15th cent.).
• Judah ben Solomon Cohen (1247).
• Judah ibn Verga (1457).
• Kalonymus ben David of Naples (1528).
• Kalonymus ben Kalonymus (130-723).
• Levi ben Abraham ben Ḥayyim (1299-1316).
• Levi ben Gershon (Leon de Bañolas), (1327-44).
• Maimon of Montpellier.
• Manoah ben Shemariyah (died 1612).
• Mashallah (754-813).
• Mattathia Delacrut (cir. 1530-50).
• Meier Neumark (1703).
• Meir Spira (14th cent. ?).
• Menahem (Emanuel) Zion Porto (1636-40).
• Meshullam Kalonymus.
• Mordecai Comtino (1460-85).
• Mordecai Finzi (1440-46).
• Moses ben Abraham (Nismes).
• Moses Almosnino (d. about 1580).
• Moses Galeno ben Elia (16th cent.).
• Moses Goli ben Judah.
• Moses Ḥandali.
• Moses Isserles (d. 1573).
• Moses ibn Tibbon (1244-74).
• Nathan Hamati ben Eliezer (1279-83).
• Raphael Leki Hannover (1734).
• Sahal (Rabban) al-Ṭabari (800).
• Samuel ibn Abbas ben Judah (1163).
• Samuel Abulafia (1278).
• Samuel Ha-Levi (1280-84).
• Samuel ben Judah of Marseilles (1331).
• Shalom ben Joseph (1450-60).
• Shalom ben Solomon Yerushalmi (1482-87).
• Sheshet ben Isaac ben Gerundi (1320).
• Sind ben Ali (829-833).
• Solomon Abigdor ben Abraham (1399).
• Solomon Davin of Rodez (14th cent.).
• Solomon ben Elijah (1344-86).
• Solomon Esobi (Azubius), (1633).
• Solomon ben Moses Melgueil (1250).
• Solomon ibn Pater Cohen of Burgos (1322).
• Solomon Shalom ben Moses (1441-86).
• Tobias Cohen (1708).
• William Raimund de Moncada (end 15th cent.).

G. J.