Mula is the nineteenth nakshatra, from 240 to 253 degrees 20 minutes of the sidereal zodiac at the start of Sagittarius, in the direction of the galactic centre. Its Vimshottari ruler is Ketu, its presiding deity is Nirriti, goddess of dissolution, calamity, and the ground beneath, and its symbol is a bunch of tied roots. The name means root or origin. Jyotisha reads Mula through Nirriti's theme of getting to the root by tearing things up, destruction that reaches the foundation, investigation that will not stop at the surface, and classes it as Rakshasa gana. It is regarded as a searching, uprooting mansion, difficult but foundational. These attributions are interpretive conventions of the tradition; the segment lies toward the dense star-fields of the galactic centre that Indian astronomy counts here.
Mula's padas fall in Leo, Virgo, Libra and Scorpio. Nirriti appears in the Rigveda chiefly as a goddess to be warded off, invoked in hymns asking for release from her domain of misfortune and dissolution rather than praised in the manner of most Vedic deities, which makes her presidency over a nakshatra unusual; some later texts identify her instead with Kali or with the earth goddess in a destructive aspect, softening the purely negative Rigvedic picture. The mansion's location toward the galactic centre was unknown to the tradition that named it, yet the reading of Mula as the point where investigation will not stop at the surface has struck some modern popular writers as an apt coincidence with the astronomical fact of a supermassive black hole lying in the same direction, a resonance worth noting as coincidence rather than claiming as intentional in the classical sources.