I corrected several typos and at least one omitted word that totally changed the sentence's meaning.
Indications that life developed independently on Mars (the determination of which is the primary purpose of the Mars rover which just set down) would be exciting . . . but BAD news for humanity. It would greatly improve the chances that in 200 years or less, humanity will be dead. Here's why:
If life is so common as to develop independently on two planets in a single solar system, then our galaxy is almost certainly CRAWLING (pun intended) with it.
If the galaxy is crawling with life, then odds are that the development of intelligence is far more common than we thought.
Based on our galaxy's mass, and an assumption that our sun is about average, there are at least 100 billion stars in the Milky Way. It's now looking as if most stars have planets.
Despite this, we're not detecting any radio or other signals that would indicate anyone is out there. We've scanned vast portions of the sky and haven't found life ANYWHERE. We're not done looking by any means, but it's clear that intelligence isn't exactly an every day occurrence.
But if life is all around us, we should have found some intelligent species. We haven't . . . which is perplexing.
If the galaxy is an unfriendly place, this might make sense. Everyone intelligent is HIDING.
There's a second line of reasoning: If humanity continues progressing, it will surely manufacture its first Von Neumann devices within 200 years. Von Neumann devices are self-replicating machines we could launch to other stars. They'd take tens of thousands of years to reach each star, but that wouldn't matter. Machines are patient. When the devices arrived, they would proceed to mine the resources and energy of the star and send duplicates of themselves to several other stars.
Von Neumann devices could "colonize" our galaxy in 200 million years. In a 14 billion year old universe, 200 million years is the blink of an eye. It should have happened in the Milky Way by now.
But there are no signs of Von Neumann devices in our Solar System. There are no obvious signs that our Solar System has ever been mined for resources.
So it doesn't look as if any intelligent species in our galaxy has ever created something that humanity will almost certainly create in the next 200 years.
Why not??
It could be that life and even intelligence are common events, but humanity is bucking, *ahem*, "astronomical" odds by being the very first intelligent species in what will be a long line. Highly Unlikely. If Mars shows signs of life, it's reasonable that our galaxy would have produced tens of thousands of species more intelligent than chimpanzees. The odds are overwhelming that some of them would be further along technologically than we Earthlings.
It could be that despite the prevalance of life, that intelligence remains uncommon. Definitely possible... but the development of intelligence is currently thought to be less astonishing than the development of life. Here on Earth, quite a few species are evolving in the direction of high intelligence.
It might be that intelligence is a common event, but a fatal one. Intelligent creatures NEVER gets to the point of creating Von Neumann devices. Never. There are many explanations for why that might be. Most of them are bad, seeing as how we are almost to the point of creating them ourselves.
As I said earlier, it could be that such species are hiding. If so, it's probably for good reason. Humanity, unfortunately, hasn't been hiding. With our unfiltered radio and TV broadcasts, we've been a veritable "Here we are! Come get us!" beacon for the last 100 years.
If this last is the explanation, we'll probably get an answer from someone before long. We probably won't much care for what one of these "Unfriendlies" has to say.
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