In astrology, exaltation is one of the five essential dignities of a planet. The exaltation is a place of awareness for the planet, whereas the fall is a position of weakness concerning the function of the planet. The sign position directly opposite a planet's sign of exaltation is considered to be its fall. Each of the seven traditional planets has its exaltation in one zodiac sign. The positions are: Sun: 19th degree of Aries (i.e., 18°00' - 18°59') Moon: 3rd degree of Taurus Mercury: 15th degree of Virgo Venus: 27th degree of Pisces Mars: 28th degree of Capricorn Jupiter: 15th degree of Cancer Saturn: 21st degree of Libra Exaltations have also been attributed to the north node (3rd degree of Gemini) and the south node (3rd degree of Sagittarius). These positions are listed in astrological texts of the early medieval Arabic period, such as al-Biruni's 11th-century Book of Instruction in the Elements of the Art of Astrology. Whilst modern Vedic astrologers place significance on the exaltation positions of the nodes, the western astrological tradition transmitted through medieval Europe demonstrates little use of them in practice traditionally and currently. Al-Biruni also points out that, in contradiction to the Greeks and Persians, the Hindu astrologers of his period disagreed upon the degree positions of the Sun, Jupiter and Saturn, and did not recognize the exaltations of the nodes - a principle he described himself as being "quite proper". The exaltations are one of the most ancient astrological factors still in use. They are used in ancient Mesopotamian astrology from an era which pre-dates the known use of the zodiac (using reference to constellation positions which shows correspondence with those later attributed to zodiac degrees). Francesca Rochberg has pointed out that since the system is found in the tradition of Enuma anu enlil, its roots may extend into the second millennium BCE. Joanne Conman believes that certain decan stars the ancient Egyptians venerated in Middle Kingdom Coffin Texts appear to be the source of the "places of secret" of the later Babylonian astrological texts referenced by Rochberg and of the corresponding planetary exaltations or hypsomata of Hellenistic astrology. The coffin texts pre-date attested Babylonian astrological texts. The pattern of the honored decans matches and appears to account for the pattern of the exaltation for four of the planets. Why the Babylonians considered these placements to be dignified is not known to Western astrologers.