kinda, dark energy is the unknown explanation for the expansion of the universe. Once we understand it enough to know what it is responsible for it’ll no longer be dark.
I think you missed my point, I don’t believe we have a self sustaining population on earth (yet)
I don’t disagree that having a self sustaining population of humans somewhere other than earth will be an important milestone.
But a much more pressing milestone is a the first self sufficient population, which I don’t see mars supporting
Hard to choose a favorite element, the Mc Escher macaroni, the swordless king of spades, the unified houses of spades & hearts under their androgynous queen, the well known face card ace of hearts or the angstrom of black butts…