Life Out There

July 30, 2010 by J Paul Douglas · Leave a Comment
Filed under: Commercial Space Flight

A bit of a brouhaha was raised last week when Dimitar Sasselov, an astronomer at Harvard University, presented Kepler space telescope data at the TEDGlobal conference in the United Kingdom. He stated that the data shows around 140 worlds to be “like Earth.” Many in the media and the general public took him to mean that these planets potentially harbor life.

Let’s set the record straight. Dr. Sasselov was strictly referring to the size of these worlds. Using Kepler data, Sasselov and his team employ something called the transit method of planet detection. That is, they observe the change in the amount of light emanating from the parent star as the planet passes — or transits — in front of it. If you plot that change on a graph, it forms what astrophysicists call a “light curve.” And that curve can tell you, within a certain unavoidable margin or error, the size of the transiting planet. This method could not, however, tell you about the surface characteristics of the planet, let alone whether life may exist there or not.

What I find very interesting about so many scientists searching for life out in the universe is their predilection for earth-like conditions. For example, you hear many references to the “Goldie Locks” or the “habitable” zone. These terms are meant to describe the area of our own solar system inhabited by the earth: not so far from the sun as to freeze our planet and not so close as to boil; just right. This zone turns out to have been ideal for the formation of life — and here’s the salient point — “as we know it.”

I’m reminded of a cartoon I saw some years ago depicting an astronaut on some far flung planet focused intensely on a rock lying near his feet and proclaiming “no life here” to mission control. Being so intent on the area surrounding his feet, he completely overlooks the 8-foot alien standing right over him.

It’s no intentional bias to which we, as humans, resort when we use earth life as our standard of measure. After all, having never met an alien, we have no other source of reference. Still, one would think that we as a species have reached a level of intellectual maturity that would preclude a preoccupation with our feet. We’d like to regard ourselves in the way the Prince of Denmark describes in Shakespeare’s Hamlet:

What a piece of work is a man, how noble in reason, how infinite in faculties, in form and moving, how express and admirable in action, how like an angel in apprehension, how like a god!

The overwhelming likelihood when we finally do encounter extraterrestrial life (note the foregone conclusion) is that it will bear no resemblance to us, whatsoever. Our biology comes as the culmination of a nearly infinite number of random events. Change one of them, and the end product may take a drastically divergent path. And the odds that another form of life that emerged and developed elsewhere in the universe would resemble us are infinitesimally small; essentially zero.

So when we cast a gaze outward towards other planets, we might do well to keep an open mind, to make no assumptions and to take life as we find it and not as we expect it to be. It would be an awful pity to overlook what would surely be one of the most profound discoveries in human history, because we didn’t simply open our eyes and see.

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