A philosopher and an astronomer in Utah may have found evidence that the Chinese were *not* the first to spot the comet that would become known as 1P/Halley.
Instead, they say, that honor goes to the Greeks, who recorded a comet in the sky when a wagon-full of meteor slammed into the northern Hellespont region sometime between 467 and 466 B.C.—about two centuries before the Chinese mention.
—Image courtesy NASA
Halley’s comet is so named because English astronomer Edmond Halley was the first to recognize that this particular celestial visitor returns to Earth on a periodic timetable. Not as regular as the milkman, for sure, but roughly every 75 to 76 years, give or take.
Halley had seen a comet in 1682, and based on the records, he thought it must be the same comet as one that had passed by in 1531 and 1607.
In fact he was so sure of this connection that he published a paper in 1705 predicting the comet would be back in 1758.
Poor Halley didn’t live long enough to see his prediction come true—but it did, and it was first spied on Christmas Day too!
Since then astronomers have dug deep into the archives, recovering 23 historic appearances of the comet before 1531—one for every time the icy body swept past Earth.
We’ve also seen the comet flying our friendly skies in 1835, 1910, and 1986, and we’re expecting it again in 2061.
Until now, the earliest credible recording of Halley’s comet was from a Chinese text called Shih chi that talks about sightings of a “broom star” in 240 B.C.
But according to Daniel Graham and Eric Hintz of Brigham Young University, ancient Greek writings from 466 to 467 B.C. note that a comet was visible in the western sky for 75 days around the time of the meteor crash.
The event was accompanied by strong winds and shooting stars.
Using a new computer simulation of the comet’s historic path, the pair calculates that Halley’s comet would have been visible from June 4 to August 25 in 466 B.C., for a total of 82 days maximum, depending on the weather.
In July, a time of annual high winds in Hellespont, the comet would have been crossing the western skies, the model predicts.
Also in July, the model shows that Earth would have been moving under the comet’s tail, which means meteors shed by the comet might have been raining into our atmosphere.
[As an aside, the debris trail left by Halley's comet actually creates an annual sky show called the Orionid meteor shower ...]
The simulation and its implications will undoubtedly get checked by other scientists to see if the Brigham Young model is strong enough to firmly link the Greek report with the famous comet.
“It’s tough going back that far in time. It’s not like an eclipse, which is really predictable,” Hintz told BBC News.
“But we feel fairly good about this. If the [sighting] in 240 B.C. is accepted, this has a fairly solid possibility.”
PS: It’s possible that crash-landed meteor the Greeks mentioned was a small asteroid thrown into a collision course with Earth by gravitational influences from comet Halley. But, Hintz said, “my feeling is that it was just a really cool coincidence.”