If they just “discovered” this comet, how do they know it came by here 50,000 years ago??? Did the Neanderthals leave reports behind????
They can calculate its orbit and it is very large..............
Astrophysics. By tracking the positions of the comet as comes into the solar system, they can calculate what the orbit is.
When they know the orbit, they know the period of the orbit.
It is fairly straightforward orbital mechanics.
I was thinking the same sort of thing because of this little clue:
“C/2022 E3 (ZTF) is a long-period comet believed to come from the Oort Cloud, the most distant region of Earth’s solar system and consisting of icy chunks of space debris. The comet was discovered a year ago, and scientists have been studying it since.
We don’t have an estimate for the furthest it will get from the Earth yet — estimates vary — but if it does return it won’t be for at least 50,000 years,” [Jessica Lee, an astronomer with the Royal Observatory”
Could this be the very first solar visit since being jostled loose from the Oort Cloud? In fact, technically, Ms Lee only talked about if it returns in 50k yrs, not that it was here 50k yrs ago...
That would seem to also fit with the 50k yr visit interval calculations...
If you take the trouble to learn a little bit about orbital mechanics, you'll answer your own question.