https://en.wikipedia.org/wiki/Silurian_hypothesis
"The Silurian hypothesis is a thought experiment[1] which assesses modern science's ability to detect evidence of a prior advanced civilization, perhaps several million years ago. In a 2018 paper, Adam Frank, an astrophysicist at the University of Rochester, and Gavin Schmidt, director of the NASA Goddard Institute, imagined an advanced civilization before humans and pondered whether it would "be possible to detect an industrial civilization in the geological record".[2]"
The geological record is an interesting possibility -- but a better question might be:
"If you wanted to preserve the record of an advanced civilization across super long periods of time -- how would you do it?"
I've thought about this question long and hard.
Stone buildings seem to last no more than 10,000 years, and by the time they are discovered, they have usually been ransacked by grave-robbers and treasure-hunters:
https://en.wikipedia.org/wiki/List_of_oldest_known_surviving...
Satellites would fall out of orbit by that time, and I don't know any piece of high-technology that has had an uptime of more than maybe 20 years... the more complex something is -- the more prone to failure it becomes.
A USB Drive from an advanced civilization in our past -- just wouldn't make it through to today...
So here's my idea:
Why not put the knowledge of an advanced civilization, into the DNA of some plants? 98% of DNA is unused, aka, non-coding DNA, aka, "Junk DNA":
https://en.wikipedia.org/wiki/Non-coding_DNA
So... why not put it there?
But... there's a problem! DNA is going to shift around a bit over time, so we're going to need to account for that! (We'd accomplish this by replicating the same information over and over at least several times).
So with all of that in mind -- here is my top candidate as one potential carrier of that information:
https://www.sciencemag.org/news/2010/10/scienceshot-biggest-...
The Flowering Plant: Paris Japonica
Why?
Its DNA apparently contains 130 billion base pairs... that's a lot of room for information, and replication of that information!
Maybe there's something in there, or then again, maybe I'm a crackpot!
History will tell! <g>
But, that would be my top candidate for where that information might be, if it exists anywhere at all...