Comets, historical records and vedic literature

Abstract

A verse in Book One of the Rigveda mentions a cosmic tree with rope-like aerial roots held up in the sky. Such an imagery might have ensued from the appearance of a comet having a ‘tree stem’-like tail, with branched out portions resembling aerial roots. Interestingly, a comet referred to as ‘heavenly tree’ was seen in 162 BC, as reported by old Chinese records. Because of weak surface gravity, cometary appendages may possibly assume strange shapes depending on factors like rotation, structure and composition of the comet as well as solar wind patterns. Varāhamihira and Ballala Sena listed several comets having strange forms as reported originally by ancient seers such as Parashara, Vriddha Garga, Narada and Garga. The Mahābhārata speaks of a mortal king Nahusha who ruled the heavens when Indra, King of Gods, went into hiding. Nahusha became luminous and egoistic after absorbing radiance from gods and seers. When he kicked Agastya (the southern star Canopus), the latter cursed him and he became a serpent and fell from the sky. We posit arguments to surmise that this Mahābhārata lore is a mythical recounting of a cometary event wherein a comet crossed Ursa Major, moved southwards with an elongated tail in the direction of Canopus and eventually went out of sight. In order to check whether such a conjecture is feasible, a preliminary list of comets (that could have, or did, come close to Canopus) drawn from various historical records is presented and discussed.