During the centuries when Venus was a comet, it had a tail.
The early traditions of the peoples of Mexico, written down in pre-Columbian days, relate that Venus smoked. "The star that smoked la estrelle que humeava, was Sitlae choloha, which the Spaniards call Venus."
"Now, I ask," said Alexander Humboldt, "what optical illusion could give Venus the appearance of a star throwing out smoke?"(1)
Sahagun, the sixteenth century Spanish authority on Mexico, wrote that the Mexicans called a comet "a star that smoked."(2) It may thus be concluded that since the Mexicans called Venus "a star that smoked," they considered it a comet.
It is also said in the Vedas that the star Venus looks like fire with smoke.(3) Apparently, the star had a tail, dark in the daytime and luminous at night. In very concrete form this luminous tail, which Venus had in earlier centuries, is mentioned in the Talmud, in the Tractate Shabbat: "Fire is hanging down from the planet Venus."(4)
This phenomenon was described by the Chaldeans. The planet Venus "was said to have a beard."(5) This same technical expression ("beard") is used in modern astronomy in the description of comets.
These parallels in observations made in the valley of the Ganges, on the shores of the Euphrates, and on the coast of the Mexican Gulf prove their objectivity. The question must then be put, not in the form, What was the illusion of the ancient Toltecs and Mayas? but, What was the phenomenon and what was its cause? A train, large enough to be visible from the earth and giving the impression of smoke and fire, hung from the planet Venus.
Venus, with its glowing train, was a very brilliant body; it is therefore not strange that the Chaldeans described it as a "bright torch of heaven,"(6) also as a "diamond that illuminates like the sun," and compared its light with the light of the rising sun. (7) At present, the light of Venus is less than one millionth of the light of the sun. "A stupendous prodigy in the sky," the Chaldeans called it.
The Hebrews similarly described the planet: "The brilliant light of Venus blazes from one end of the cosmos to the other end."
The Chinese astronomical text from Soochow refers to the past when "Venus was visible in full daylight and, while moving across the sky, rivalled the sun in brightness."
As late as the seventh century, Assurbanipal wrote about Venus (Ishtar) "who is clothed with fire and bears aloft a crown of awful splendour."(3) The Eqyptians under Seti thus described Venus (Sekhmet): "A circling star which scatters its flame in fire. . . a flame of fire in her tempest."(4)
Possessing a tail and moving on a not yet circular orbit Venus was more of a comet than a planet, and was called a "smoking star" or a comet by the Mexicans. They also called it by the name of Tzontemocque, or "the mane." (5) The Arabs called Ishtar (Venus) by the name Zebbaj or "one with hair" as did the Babylonians.(6)
"sometime there are hairs attached to the planets," wrote Pliny; (7) an old description of Venus must have served as a basis for his assertion. But hair or coma is a characteristic of comets, and in fact "comet" is derived from the Greek word for "hair." The Peruvian name "Chaska" (wavy-haired)(8) is still the name for Venus, though at present the Morning Star is definitely a planet and has no tail attached to it.