Jyothisha is the 6th vedanga which is given the status of the crown of the Vedas. The jyothisha has four branches. This is available as small books corresponding to four Vedas. They are aarcha jyothisha belongs to Rig-Veda, Yaajusha jyothisha connected with Yajurveda, Saama jyothisha and Atharvana jyothisha respectively belonging to Saama Veda and Atharva Veda. Unfortunately the Saama jyothisha book has lost for ever. All these are very small books containing few lines on the days, nights, seasons, the eclipse etc. Jyothisha has three parts : mathematics and astronomy which are pure science subjects like modern mathematics and and astronomy. But the prediction part is not a science as defined in modern terms. According to Sanskrit word Saastra, this is a Saastra. The word Saastra means which is directing/guiding /motivating. Thousands of books have been written in jyothisha . So generally everyone says that jyothisha is a Saastra, in the sense that it guides and directs our life , the past, present and future. It is Varaha mihiraacharya who has contributed maximum for the prediction part of the Jyothisha in the 6th century AD