Rāhu and Ketu

Summary

In Indian tradition Rāhu and Ketu are the head and body of an Asura who drank the drink of immortality: his head was cut off, and the head stayed alive in the sky chasing the sun and moon and swallowing them, which is what eclipses are, while the body became Ketu. Indian astronomers count them among the nine planets, and in their reckoning they are the two nodes where the moon's path crosses the sun's, where eclipses happen. Monier-Williams gives Rāhu as "the Seizer", and Ketu in its oldest senses as bright appearance, banner and sign, then comet and meteor.

The oldest form of the story is in the Rigveda: Svarbhānu, of the Asuras' line, pierces the sun with darkness, and people look like those who do not know where they stand, until the sage Atri finds the sun hidden in the darkness and restores it.

The Mahābhārata then tells the full story in the account of the churning of the ocean. When the drink of immortality, amṛta, came out of the ocean, Viṣṇu took it in the form of a bewitching woman and gave it to the gods. One of the Dānavas, named Rāhu, sat among the gods in a god's guise and drank; when the drink had reached his throat, the Sun and the Moon recognised him and told the gods, and Nārāyaṇa cut off his head with his discus. The huge head, like a mountain peak, rose to the sky uttering dreadful cries, and the trunk fell to the ground rolling, so that the earth shook with its mountains, forests and islands. Since that day there has been unending enmity between Rāhu's head and the Sun and Moon, and to this day it swallows them. The Bhāgavata Purāṇa adds that the head became immortal because the drink had touched it, so Brahmā made it one of the planets, and it attacks the sun and moon on the nights of new and full moon.

The Viṣṇu Purāṇa describes the planets in their chariots: eight black horses draw the dusky chariot of Rāhu, harnessed to it once and for ever, and on the nodal days, the eclipses, Rāhu passes from the sun to the moon and back from the moon to the sun; the eight horses of Ketu's chariot are the dusky red of lac or of the smoke of burning straw; and the chariots of all nine planets are fastened to the pole star by cords of air. Its translator Wilson says that making the body immortal under the name of Ketu, and the cause of meteors, seems to have been an afterthought.

In the sixth century the astronomer Varāhamihira gathered in his Bṛhat Saṃhitā what people said about Rāhu: that he was an Asura whose head was cut off and who did not die because he had tasted the drink of immortality; that he has a black disc which is seen only at eclipses by a boon of Brahmā; that he is shaped like a serpent whose head is severed from its tail; that he has no body and is only darkness, a son of Siṃhikā. Then he asked: if he has a body moving on a fixed path, how does he eclipse the sun and moon when they are half the sky away from him? And he said: the truth is that in her eclipse the moon enters the shadow of the earth, and in the sun's eclipse the moon hides the sun from below, like a cloud. Al-Bīrūnī put these words into Arabic in his book on India around 1030 and called Rāhu "the Head", as Arab astronomers called the two nodes "the Head and the Tail".

The two passed with Indian astronomy into China and Japan. The nine luminaries of Japan, Kuyō, are the sun, the moon and the five planets, with 羅睺, Rago, and 計都, Keito. The Heibonsha encyclopedia says that a Chinese book of the early ninth century calls the first "the god of the eclipse's head" and the second "the god of the eclipse's tail"; that an Indian astronomer in China, Gautama Siddha, translated in 718 a book of Indian astronomy he called "the reckoning of the Nine Graspers", rendering navagraha, the nine planets, the Chinese word translating the sense "seizer" in graha; and that the figure of the nine luminaries, a large circle ringed by eight small ones, became a crest of Japanese houses.

The idea the story turns on is that the one who stole immortality was split in two: a living head without a body and a body without a head, and the head chases the sun and moon that exposed him and swallows them again and again. The same story served the reckoning: the two points where eclipses happen became the head and the body, and when astronomers explained eclipses by shadow the two names stayed, "the Head and the Tail" among the Arabs, "the head and tail of the eclipse" in China.

We read the two names in the Arabic tongue like this, as a reading proposed on the method, since the project's essays do not read them. Rāhu has two consonants, r and h; the u is the stem vowel of the noun. We read it from the nucleus r-h of Arabic rahiqa: in Lane rahiqahu is "he, or it, came upon, properly as a thing that covered, him", "reached, or overtook, him", "followed him, and was near to reaching him", and the Qur'an says "no darkness shall cover (yarhaqu) their faces". That is what Rāhu does: he follows the sun and moon, overtakes them and covers their faces with darkness, which is what the Sanskrit dictionary says his name means, "the Seizer". Arab astronomers call him "the Head", and in the story he is only a head. Ketu we read as Arabic qaṭṭ: in Lane qaṭṭahu is "he cut it breadthwise, across", and qaṭṭa al-qalam is "he cut off its head across", of a reed pen; q becomes k and ṭ becomes t. On this reading Ketu is the body whose head was cut off, which the Arabs call "the Tail".

Linguistic Root

Rāhu between rahiqa and raʾs

Monier-Williams derives rāhu from the verb rabh, to take hold of, notes in an older edition that it is said to come from rah, and gives its meaning as "the Seizer". He says the word graha itself, a planet, means "seizer (eclipser)", is used of Rāhu or the dragon's head, then of any planet, and that nine are counted: sun, moon, the five, Rāhu and Ketu.

The name Rāhu has only two consonants, r and h. The Juthoor method looks at a nucleus as well as a full root, and in Arabic these two letters are the nucleus of r-h-q, which holds covering and overtaking: rahiqahu is "came upon him as a thing that covered", "overtook him", "followed him and was near to reaching him", and "I sought such a one until I drew near to him, and, as it sometimes means, took him". The q is a third letter with nothing to answer it in the Sanskrit name. The second reading comes from the meaning, not the letters: Arab astronomers called the two nodes "the Head and the Tail", as Lane notes, and al-Bīrūnī, quoting Varāhamihira, calls Rāhu "the Head". The hamza of raʾs may answer the h, both being throat sounds, but its s has nothing to answer it.

Ketu and qaṭṭa

Monier-Williams derives ketu from the verb cit, to appear, to shine, and gives it in the Rigveda as bright appearance and rays of light, then banner and sign, then any unusual phenomenon, comet and meteor, then the descending node and the severed body of the Asura. Varāhamihira says that ketus are luminous appearances like fire that do not burn, some in the sky, some in the air and some on the earth; that some count a hundred and one and others a thousand; and that Nārada says there is one Ketu appearing in many shapes. So the oldest sense is appearing and shining, and qaṭṭa reads the name by what it became in the story: the body whose head was cut off across, as the head of a reed pen is cut.

The shifts: q becomes k, as it does into Greek and Latin in the Juthoor table, and ṭ becomes t, since Sanskrit has no emphatic sounds.

Key Mythic Narratives

Svarbhānu and Atri

In hymn 5.40 of the Rigveda the singer says to the sun: when Svarbhānu pierced you with darkness, all creatures looked like one who does not know where he stands; then he names Indra, who struck down Svarbhānu's magic spread beneath the sky, and Atri, who found the hidden sun by his fourth prayer; then the sun speaks and asks not to be swallowed by the darkness. So in the oldest text the eclipse is the work of an Asura, and its cure the work of a sage who knows the prayer.

The mother Siṃhikā

Wilson's note on the Viṣṇu Purāṇa says that the most famous of the sons of Siṃhikā, called the Saiṃhikeyas, are Rāhu and Ketu, whom the Bhāgavata and the Vāyu Purāṇa name, Rāhu as the eldest.

Symbolic Reading

The essay rereading the Indian myths reads the churning of the ocean as a chemical extraction: the churning is stirring and distilling, the amṛta the useful substance that comes out at the end; and it reads the number 108 as an astronomical reckoning of the distances of sun and moon. That is its reading of the great story Rāhu comes out of.

The essay rereading the Japanese myths reads Amaterasu's hiding in the cave as a solar eclipse or the winter solstice.

In the Indian texts themselves Rāhu moves from story to reckoning: in the Mahābhārata he is a head that cries out, in the Viṣṇu Purāṇa a chariot with horses, and in Varāhamihira a name for a point where an eclipse is calculated, of which he says that the calculation of a really learned astronomer will never fail.

Cross-Cultural Parallels

In Egypt Apophis, the great serpent, attacks Ra's barque every night, trying to swallow it or to swallow the river's water until the barque runs aground, and the Egyptian essay makes him the darkness that tries to swallow the sun each night. Rāhu swallows the sun and moon at the nodes. The difference is that Apophis is defeated every night before dawn, while Rāhu cannot die and comes back at every node.

In the North the wolf Sköll chases the sun and the wolf Hati the moon, and the mightiest of the Ironwood giantess's brood, Mánagarmr, "Moon-hound", swallows the moon and spatters the sky with blood, as told on the Sól and Máni page. In both the eclipse is a chase; in India the chaser is a head, in the North a wolf.

In China the Huainanzi says: "The moon lights all under heaven, yet it is eaten by the toad", and the toad in the moon is what Chang'e became when she stole the drug of immortality. The Records of the Grand Historian say that the "Heavenly Dog" looks like a great shooting star with a sound, and that where it comes down to earth it is like a dog, and that it passed over the land of Liang when the seven kingdoms rebelled. The toad eats the moon as Rāhu does, and the Heavenly Dog is a meteor as Ketu is meteor and comet.

Rāhu drinking the amṛta in disguise and losing his head belongs to the food of immortality, his disguise among the gods to the trickster, and the enemy who waylays the sun to the sun's journey.