The search for other life in our solar system

June 22, 2016

Also available on YouTube

Hello and welcome to my audio programme.

Imagine that after a terrible ordeal at sea, some planks of wood from your ship manage to help you to wash ashore on an island.  You regain consciousness, remember the ordeal, then are happy to be alive.  But looking around, you soon realize that you are stranded on a small island with no other people and you become lonely.  In frustration, you heave up the nearest rock and hurl it away, only to find that, to your surprise, a gold coin had been hidden underneath it.  Picking up the coin and inspecting it, you cannot determine the origin of the coin.  You then look around the island once more and observe many similar rocks.  You have plenty of wealth back home and the primary value of discovering another coin would be paired with the hope of gaining further insight into the origin of such coins.  How hopeful are you at this point to find more gold coins under more rocks?  Picking up several more similar rocks does not yield any more gold coins.  How excited are you at this point to find more gold coins under more rocks?  As you spend your days on this island planning your survival and escape or waiting for rescue, will you choose to overturn every similar rock?

In this audio programme, I’ll be discussing the search for nearby life in our solar system.

I was recently watching a video that had been uploaded to YouTube of a panel discussion that took place at an Arizona State University site.  It included two Nobel Prize winners, along with the familiar faces of several science communicators.  Some of their discussion involved life in or on other bodies in our very own solar system.  What motivates some people to be interested in this?

One of the ideas is that a big rock could have slammed into the Earth and resulted in life-carrying rocks reaching Mars.  Let’s examine a potential chain of what-ifs for this scenario.

Ok, a big rock slams into the Earth sometime after life has appeared.  Next, this rock is big enough to throw pieces of Earth into outer space and not so big as to destroy all life and to make the world uninhabitable, because we’re here, today.  Next, at least one piece of Earth that is thrown into outer space has life on it.  Next, that piece of Earth accidentally finds its way to Mars.  Next, the Earth-life on that piece is not obliterated by the journey through outer space.  Next, the Earth-life survives the collision with Mars.  Next, the Earth-life either persists as it was all the way until today, or it finds Martian conditions conducive to evolution and we find Martian life that is cousin to Earth-life.  Try coming up with percentages for your certainty in these events and multiplying them together.  For the simplest definition of Earth-life, we could simply mean “organic molecules.”

In reality, we’ve now deployed equipment to Mars.  What would be your guess that some Earth-life hitched a ride and is just waiting for some liquid water and some dust in order to reproduce itself?

Another possible idea from the set of ideas of “Panspermia” is that life might not have spontaneously appeared on Earth, but might instead have arrived from elsewhere, perhaps via a mechanism like the one just described for Mars.  This is a fun idea, but to consider it seriously, what motivation is there?  Is there a deep dissatisfaction with the idea that life on Earth could have arisen by accident?  Is there a deep loneliness and so wishful thinking about a cousin, out there?

Let’s pretend that the spontaneous appearance of life on Earth was very unlikely.  Let’s pretend that another body in the Universe existed with conditions we imagine to have been highly conducive to the spontaneous appearance of life.  Now we are faced with the challenge of getting the life from there to here.  Perhaps we can make the journey more likely by having that body right here in our solar system, being later destroyed or hidden away.  In other words, life is so baffling that it probably came from somewhere else.  That has an extremely familiar cadence, to it, for me.  Do you recognize it from your own experiences?  Also, by substituting one set of challenges for another, what do we gain?

There are some expressions and notions which might be worth-while keeping in mind: “Necessity is the mother of invention”, “keep it simple, stupid”, Occam’s razor.

Comparing the pre-life planet Earth and some other body X in the Universe more conducive to the spontaneous appearance of life, we can ask a lot of questions: Would X have more volcanoes or fewer volcanoes?  Would X have more water or less water?  Would X have more dust or less dust?  Would X have more earthquakes or fewer earthquakes?  Would X have more frequent tides or less frequent tides?  Would X be generally more violent (like today’s Jupiter) or calmer (like today’s Moon, or like today’s Mars)?  Was our balance here on Earth really so horrible, when we look around?

A quote from H. P. Lovecraft reads, “The humanocentric pose is impossible to me, for I cannot acquire the primitive myopia which magnifies the Earth and ignores the background.”  What is “the humanocentric pose”?  Perhaps it includes that which we identify with: Thinking people, less so primates, less so mammals, less so animals, less so Earthly life, less so the Earth itself.  If we do identify with Earthly life, indeed, does there not appear to be at least a slight obsession with projecting Earthly life underneath every rock on our island?

A diversity of interests ought to strengthen science.  How many articles have you discovered discussing other life in our solar system?  Is it a meme fueled by humanocentric attitudes?

Surely there are a vast number of bodies in the Universe and perhaps even our galaxy having life, but why is there so much attention and excitement about finding it near here?

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