Hydrae. As for how far up Hydraâs body the tail extends, we gather from Pseudo-Eratosthenes ( Catasterismi 41) that Corvus/the Raven was regarded as being perched on the tail. Ï (Pi) Hydrae and γ (Gamma) Hydrae together form a distinctive last part of the tail, which is essentially parallel to the ecliptic. 23 From γ (Gamma) Hydrae upwards, the tail curves sharply and heads toward the south. It was on this stretch, between γ (Gamma) Hydrae and the coil associated with β , ο , and ξ Hydrae, that Corvus/the Raven rested and the tail commenced ( fig. 14.8 ).
FIG. 14.8 The tail of Hydra, the Serpent. The tip was Ï (Pi) and the tail extended up approximately to where the very faint star HIP59373 is. Image credit: Sirscha Nicholl.
The star γ (Gamma) Hydrae rose approximately 54 minutes before Ï (Pi) Hydrae. If γ (Gamma) Hydrae was the radiant of the meteors, then, the meteor storm would have had to occur during that 54-minute period. If the radiant was at, say, HIP59373 (the part of Hydra on which Corvus/the Raven perched), then the meteor storm would have had to have taken place within the 1 hour and 44 minutes between its rising and Ï (Pi) Hydraeâs rising. It was a moonless sky.
The meteor display in Hydra is probably responsible for the peculiar appearance of Hydra, as described in Revelation 12:3âthe constellation figureâs fiery appearance, its seven crowns, and its ten horns. Notably the author of Revelation counts this description of Hydraâs appearance as an integral part of the second extraordinary sign in heaven (vv. 3â4). At the time of the meteor storm, Hydra would have stretched upwards just over a third of the way from the eastern (ESE/SE) horizon to the western (W/WSW). That is striking, because Revelation 12:3 states that one-third of the stars in the dome of the sky seemed to be thrown to the earth. That would seem to mean that no meteor streak commenced beyond that point, although many meteors presumably extended beyond it.
To discover the orbit of the meteoroid stream responsible for the meteor storm radiating from a point between γ (Gamma) Hydrae and HIP59373, in the relevant window of time, from the Near East, I approached David Asher of the Armagh Observatory.
Nailing down an orbit for an ancient meteoroid stream is no easy businessâcalculations must take into account the rate of Earthâs rotation, precession of the equinoxes, and many other factors. Plus, it is unclear from Revelation 12:3â4 what the velocity of the meteors was.
Meteor storms are typically related to short-period comets, either Jupiter-family comets (orbital period: 3â20 years) or Halley-type comets (orbital period: 20â200 years). However, long-period comets with orbital periods up to 10,000 years can give rise to meteor outbursts, and cometary asteroids might also conceivably give rise to meteor storms.
David Asher worked out a range of possible orbits for the meteoroid stream that caused the 6 BC Hydrid meteor storm. 24 Any of the orbits in table 14.1 could theoretically have caused a meteor storm at the relevant time, radiating from γ (Gamma)