Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 5 · Portents, Comets
ग्रहचारः केतवश्च
विकचाख्या गुरुसुता वेष्टा याम्ये स्थिता अपि ।सूक्ष्माः शुक्ला बुधसुताश्चौररोगभयप्रदाः ॥ १०४ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 56, verse 104.
The sons of Jupiter are called Vikacha. They are bad too, even standing in the south. The small white sons of Mercury bring fear of thieves and illness.
Simple meaning: Jupiter's comets are bad even in the south. Small white comets of Mercury bring fear of thieves and illness.
Classical view, not medical advice.
कुजात्मजाः कुंकुमाख्या रक्ताः शूलास्त्वनिष्टदाः ।
Red spear-shaped comets of Mars are bad. Fire-coloured comets of Agni bring comfort.
अरुणाः श्यामलाकारा अर्कपुत्राश्च पापदाः ।
Dusky comets of the Sun are bad. Star-like comets of Venus are good.
कृत्तिकासु भवो धूमकेतुर्नूनं प्रजाक्षयः ।
A comet in Krittika can mean loss of people. One on palaces or trees can harm kings.