The Kalachakra system is the basis for modern Tibetan astro science, and recognizes ten “planets”: Sun, Moon, the naked eye planets, the moon's north and south nodes (Rahu or sgra can and Kalagni or dus me), and a comet named Ketu or mjug ring. Chinese astronomical systems do not include the nodes or the comet, and the classical Indian systems do not recognize the comet (although the name Ketu is used for the southern lunar node). Rahu and Ketu are described as the head and tail of a sky-blue dragon. Due to their color, they are only visible during an eclipse. The Hindu explanation of eclipses is the demon Rahu attacking the sun or moon, but in the Kalachakra system eclipses are correctly described as an alignment of the sun, moon, and appropriate lunar node. Eclipses have been successfully predicted for centuries in Tibet. Also, although many discussions of archaeoastronomy include sweeping statements that all ancient cultures feared eclipses, in the Tibetan tradition they are instead considered to be auspicious occasions. Karma (either positive or negative) accumulated during an eclipse is multiplied millions of times.
It is interesting to note that in some early scriptural texts the planets are pictured as spherical bodies suspended in space.
The ten planets are as follows:
Sun nyi ma
Moon zla ba
Mars mig dmar
Mercury lhag pa
Jupiter phur bu
Venus pa sangs
Saturn spen pa
Rahu sgra can
Kalagni dus me
Ketu mjug ring
Astro Department (1995) Tibetan Astronomy and Astrology - a Brief Introduction. Dharamsala, India: Tibetan Medical and Astro Institute.
Dalai Lama (2005) The Universe in a Single Atom. NY: Morgan Road Books.
Gyatso, Khendrup Norsang (2004) Ornament of Stainless Light: An Exposition of the Kalachakra Tantra. Boston: Wisdom Publications.