Millions of years into the future, humans may not exist anymore.
It might seem like a scary thought, but it's not something we need to worry about.
Lots of species go extinct over time, and it's only natural that one day it could happen to humans too.
If humanity, just like the dinosaurs one day becomes history - scientists now think they've found a way to bring us back.
They've printed the blueprint for what makes a human, called a genome, on something called a '5D memory crystal'.
The hope is that at some point in the future someone or something - yes, that could be aliens - will find it and make new humans using the information stored inside.