Wednesday, June 25, 2008
There IS Life on Mars
The Mars Phoenix Mission is a robotic spacecraft on a mission to Mars to search for environments suitable for microbial life, and to research the history of water there.
But I don't want to talk about how amazing this mission is (and it is), or how unbelievable it is that we can get color images from the surfaces of other planets. No - this blog focuses on one assumption: What would it mean if there IS life on Mars?
In my mind, if there is evidence of life on mars (which presumably could have lived there over a billion years ago) life in the Universe is no longer "special". In fact it would lead me to believe that life in the Universe is abundant, though spread out through cosmic time depending on the specific life of the stars and planets involved. In fact there is an equation (The Drake Equation) that predicts the likelihood that we could come in contact with intelligent life in our solar system.
The Drake equation states that:
where N is the number of civilizations in our galaxy with which communication might be possible; and
R* is the average rate of star formation in our galaxy
fp is the fraction of those stars that have planets
ne is the average number of planets that can potentially support life per star that has planets
fℓ is the fraction of the above that actually go on to develop life at some point
fi is the fraction of the above that actually go on to develop intelligent life
fc is the fraction of civilizations that develop a technology that releases detectable signs of their existence into space
L is the length of time such civilizations release detectable signals into space.
To think in an almost unbounded Universe that not only is there life out there, but there was life just next door, as the Phoenix potentially could show, suggests that life is not precious but maybe still fleeting. Moreover - the genetic variability in complex life would be so wild, we probably can't imagine what other life could look like. Considering the genetic variety this planet has seen (not the most extreme in my mind being dinosaurs considering the extreme amounts of energy needed to keep them alive) if life is abundant, then we may not be the product of some higher power but one output of an infinite number of random number generators.
Now I am not presuming that Phoenix will find evidence of complex life, or that it will even find evidence of life. In fact it will be lucky just to find water on mars at all (see left - thanks Mike!). More likely it could find evidence of microbes. But then I don't think it would be far fetched to think that if there was life on Mars, then similar to life on our planet, simple forms of life over billions of years can evolve into the complex organisms here on Earth like the cat or the platypus, the hippopotamus or the giraffe.
In fact I am not sure that society as a whole or even our varied Religions are prepared to incorporate the fact that life could be more abundant than we previously thought and exist throughout the Universe. I think we often struggle combining Science and Religion (The old evolution versus creationism debate). If Darwinism is tough enough to grasp, then how much would we struggle to accept life outside the bounds of Earth.
Funny evolution side note. There are crabs in Japan called Samurai Crabs, or Heikengani - species of crab native to Japan, with a shell that bears a pattern resembling a human face. It is locally believed that these crabs are reincarnations of the spirits of the Heike warriors who committed suicide by jumping into the sea. Tradition follows that if a crab is caught with a Samurai face on it - it is thrown back into the sea. Carl Sagan used these crabs as an example of unintentional artificial selection (versus natural selection) where if you were a crab with markings somewhat similar to a Samurai warrior's face, you survived more often than any others, and over time you looked more and more like a Samurai warrior because of this selection!
I for one am rooting for us finding evidence for life on Mars and I am not sure why. I don't think I have completely wrapped my mind around what that would mean, but I have an inner desire for it to be true. There is a romantic and elitist notion to life only existing on Earth, but that seems to be such a lonely and cold existence. And as my next blog discusses, the case where life only exists on Earth leads me to think we need to do so much more as a species than we are currently doing to leave a legacy in the Universe (and I don't know what that is obviously).