Europan Trilobites

I was watching a YouTube video about the material that a NASA probe brought back from an asteroid.  This asteroid apparently is in a near Earth orbit and so this mission was able to reach and return from this tiny world in just a few years with its cargo of sand and gravel.  By the look of the asteroid, it’s not even a solid piece of rock but a bunch of space junk that gravitated together out in the lonely stretches of interplanetary space.

But as unpromising as this locale seems to me, apparently, it was a bonanza for science.  This one kilometer flying gravel pit somehow contains an astonishing collection of organic molecules that hint shockingly about being the precursors or even the aftermath of life.  A slew of amino acids and even some precursors of the RNA molecule showed up in this sampler that NASA recovered.

Now, reading this I immediately began to question in my own mind whether these organic molecules started out on Earth and were ejected into space during one of the asteroid collisions that befall this planet every once in a great while.  After all, if rocks from Mars have ended up on Earth (as has been claimed by geologists) then surely debris from Earth could have contaminated nearby space and ended up on this neighboring rock.  But the writers of this report have information that dates this asteroid to very ancient times.  In fact, they claim it’s older than the planets and could possibly contain material from completely outside the solar system.  Well, who knows?  Despite assurances I think it’s fifty/fifty whether it’s originally terrestrial organic material they’re looking at.

But suppose it really is extraterrestrial in origin.  In that case, I think that eventually we will find that life existed on Mars in the past when it possessed abundant water.  In fact, it’s entirely possible that life exists cryptically below the surface of Mars at a depth where temperature is higher and reservoirs of water exist.  And if organic molecules are floating around the solar system, it seems likely that some of the larger Jovian and Saturnian moons with their liquid water oceans will also turn out to contain life.

Now here’s the thing.  I would make a small wager that when these life forms are found, they will be shown to have a relationship to terrestrial organisms.  I say this because I think they will be descendants of microorganisms that have managed to be ejected from Earth and drifted through the solar system until they reached environments that they could adapt to.

Of course, it’s possible that life on Earth also came from space.  Experimentation with hardy terrestrial lifeforms has shown that they can exist in the vacuum of interplanetary space for surprisingly long periods as spores.  I guess the interesting question is just how advanced is the life that we will find in the rest of the solar system.  There is a big difference between finding bacteria, algae, lichen or moss on Mars or a jellyfish swimming in the oceans of Titan as opposed to finding the xenomorph.  Well, I won’t be greedy.  I’ll split the difference.  I’ll settle for a Europan trilobite.