Tyler Fox, one of COSI's Floor Faculty Managers, was working in the
Planetarium the other day and encountered a difficult question. What
if someday we discover alien life - say, in the subsurface oceans of
Europa or living on a distant exoplanet around another star - and it's
as complex as life here on Earth. Not just single-celled critters that
we only get to gawk at through a microscope, but large organisms with
thriving ecosystems.
Of course we would first celebrate a major triumph of scientific
inquiry and human philosophy, answering one of the most important
questions of our species: "Are we alone?"
But Tyler's gang didn't care about that question. They cared about the
second most important question of our species: "Could we eat it?"
That's actually a pretty challenging question. On one hand, complex
molecules like sugars and amino acids are built from (literally)
universal ingredients. We've even detected glycine, the simplest amino
acid, on comets and identified glycolaldehyde, a simple sugar, in
interstellar nebulae. So presumably alien life would be built from the
same basic blocks as their Earth-born cousins, rendering them eatable.
But digestible is another matter. There are many, many things just on
the Earth that are either too tough, too poisonous, or too poor in
nutrients to eat. Humans are omnivorous, but not that omnivorous.
There are many steps to go from "contains nutrients" to "we can
acquire those nutrients" to "we can enjoy doing so."
Could we eat alien life? I guess there's only one way to find out.
