Karka

Karka is the fourth rashi, the Vedic sign of the crab, corresponding to Cancer. In jyotisha it is ruled by the Moon (Chandra), the only sign the Moon governs, and it is the sign of Jupiter's exaltation. Its quality is movable (chara), the cardinal mode, and its element is water (jala tattva). Jyotisha reads Karka through the Moon's nurturing, protective, emotional nature and the crab's shell: home, mother, feeling, and the instinct to shelter. As a sidereal sign it is fixed to the stars and runs about 24 degrees behind tropical Cancer. The Moon's rulership and Jupiter's exaltation here are dignities shared with Western astrology. In a Vedic chart the strength of the Moon in Karka is weighed heavily, since the Moon is the chief significator of the mind.

Karka, crab, is a direct translation of the Greek karkinos, carried into Sanskrit through the Yavanajataka, a versification of a Greek astrological text datable to roughly the second through fourth centuries CE. The twelve equal thirty-degree signs this name belongs to were fixed centuries earlier in Babylonian celestial divination of roughly the fifth or fourth century BCE, a Mesopotamian scheme with no precedent anywhere in the older Vedic corpus, where no twelve-sign zodiac appears at all. The Moon's sole rulership of Karka and Jupiter's exaltation here, dignities jyotisha shares with the equivalent tropical Cancer, belong to a later classical layer, generally credited to compilations such as the Brihat Parashara Hora Shastra of roughly the seventh or eighth century CE, a text pseudepigraphically ascribed to the sage Parashara.

Sources Brihat Parashara Hora ShastraSage Parashara (attributed) with The Yavanajataka of SphujidhvajaDavid Pingree, Jyotihsastra: Astral and Mathematical LiteratureDavid Pingree

Chandra, the Moon, owns Karka, and it is the only sign the Moon owns. Surya owns one sign as well, Simha, while the other five grahas own two apiece. That asymmetry is structural in jyotisha and it makes Karka and Simha the two signs whose lordship cannot be shared or diluted.

Guru, Jupiter, is exalted in Karka, with the fifth degree given as the exact point. Mangala, Mars, is debilitated in the same sign, with the low point at the twenty eighth degree. The two sit near the opposite ends of the sign, which means the beginning and the end of Karka carry very different weight, and a reading that treats the sign as a uniform block will miss it. Jupiter exalted in the Moon's own sign is among the more favourably regarded placements in the system, and the classical texts return to it repeatedly.

The nakshatras crossing Karka are the last quarter of Punarvasu, then Pushya entire, then Ashlesha entire. Pushya is ruled by Shani in the vimshottari scheme and Ashlesha by Budha, and Pushya is widely regarded as among the most auspicious of the twenty seven, which sets up an unusual situation: a mansion of high standing ruled by the planet of restriction, sitting inside the Moon's own sign, in the arc where Jupiter reaches its highest dignity. Jyotisha does not resolve such convergences into a single verdict. It reads them as layers, and the layers are expected to disagree.