If?

If aliens discovered all our crap on (and circling) Mars, would they know to come find us on Earth?

If a species could evolve on another world around another star, and manage to develop the ability to think- about thinking- be cognizant of the universe and the insignificance of themselves in that place.

If said species could learn to learn, to extrapolate the nature of the cosmos from the mere scraps of reality they can perceive, and then resolve to put aside whatever differences they may consider themselves one from another.

If, at least as far as we know, competition with an overlay of cooperation makes for a mind facile enough to want to plumb the well of knowledge for both a draught of what such drink could bear, both good and ill. We hope they’re aware, they differ.

If such a time would come in the minds of our brothers across the stars on small dabs of flying mud like our own, with perhaps differing concentrations of water and snow and whatever else might comprise these spiritual kin, they would know peace.

If a peace came long enough, and their thirst for knowledge great enough, they would put all aside for a grand voyage, either by them, their machines or some fortuitous combination of both, and would strike out for worlds like their own.

If they were to be able by non-Euclidean manipulations of time or space, or spacetime or timedspace, cross the void, arriving before they left, or billions of years later, would not mind to see our scraps orbiting our homes away from home.

If they found such things, they would smile and remember when they too had finally reached the limit of things they could do at home, and remember the tentative, furtive, fearful, lonely steps to the stars. And they would find us waiting.

This answer to a question first appeared on Quora.