Can Myths Teach the Science of the 'Goldilocks Zone'?
Have you been following the news about the earthlike planet that some scientists are calling “ Earth 2.0 ”? One of the reasons this particular exoplanet is so exciting is that it happens to be in what is popularly known as the “ Goldilocks Zone .” That is, the planet is not so far away from the sun as to be too cold, and it's not so close that its water would all turn to steam. It's at that place where it's “just right,” and can support the liquid water that sustains life.
This concept of a Goldilocks Zone, more correctly called the “ circumstellar habitable zone, ” reminds me of an ancient story in which distance from the sun mattered very much. The story is about Phaethon, son of a sea nymph, Clymene, and the sun god, Helios. Ovid tells a Romanized version of the story in his Metamorphoses, and teaches us the importance of staying the course .
The Folly of Phaethon
You may know that in those far-off days it was common for gods to mate with a human or a nature spirit just once, producing one or more offspring who were special in some way. You may be familiar with some of these semi-divine heroes like Hercules, the Greek warrior Achilles, and the Trojan warrior Aeneas.
Sometimes a bastard child raised by a human mother was acknowledged by the father, but often he had no relationship at all with the god. In some tales – like this one – that can lead to a kind of identity crisis in which the young demigod feels a need to prove himself.
Phaethon's plan for proving his divine heritage to his friends was to drive the chariot of the sun across the sky, and without revealing this to Helios, he extracted a promise that he could have any one boon he asked for. Now you must understand that driving the chariot was no easy task, and it was crucial to stay on the path the sun god had marked out.
And do not please yourself, taking a path straight through the five zones of heaven! The track runs obliquely in a wide curve, and bounded by the three central regions, avoids the southern pole and the Arctic north. This is your road, you will clearly see my wheel-marks, and so that heaven and earth receive equal warmth, do not sink down too far or heave the chariot into the upper air! Too high and you will scorch the roof of heaven: too low, the earth. The middle way is safest. (Ovid Metamorphoses Bk II, 111-149)
Helios worried, but the adamant Phaethon mounted the chariot and prepared to ride it across the sky. And knowing he could not stop his boy, the sun god gave the youth one final caution: to keep a tight hold of the reins.
Scorched Earth and the Death of Phaethon
The god Helios had warned his son that even mighty Zeus couldn't ride the chariot of the son, and as soon as Phaethon was in the air he realized why. The horses immediately went wild when they didn't sense their master in the chariot, and they began to veer off course. Frightened, Phaethon dropped the reins.
And of course, that only made things worse...
The earth was scorched when the sun came too close. Lush African forests burned up and became arid deserts. Rivers and lakes dried up, and the very oceans shrank. Even the blood of the Ethiopian people rose to the surface of their skin, turning it dark forever after.
The Earth called out to the heavens for help, and the call was answered by Zeus, who struck the brave but foolish youth with a lightning bolt in order to put an end to his chaotic and destructive ride. The horses broke away from the chariot, which was pulled apart and ruined. Phaethon, all ablaze with fire, fell from the heavens to the earth.
Many times people assume that the ancients were superstitious, and had no concept of science. But while the Greeks, Romans and other ancient peoples were a lot more advanced than we gave them credit for. Many modern concepts, such as that of the atom, originated in classical Greece. It's very likely that the ancient Greeks had some understanding of a place in the solar system that was “just right” for a planet. And maybe stories like this one about Phaethon were just a fanciful way for scholars to teach these concepts to ordinary folks like you and me!
Phaethon in Contemporary Astronomy
Today we know Phaethon as “3200 Phaethon,” a rock comet that has attributes of both a comet and an asteroid. It was discovered in 1983, and was named for the son of Helios because its course takes it very close to our sun. This Phaethon is the parent body of the Geminid meteor shower, which can be seen in the middle of December each year.
The tail end of this story I'll save for another day. As all good stories from the Metamorphoses, it concerns the transformation of one body into another. And it too relates to our “close cousin” Kepler-452b, but in a different and more circumspect way...
Image Credit » https://pixabay.com/en/solar-eruption-fire-sun-space-639577/ by skeeze