Because We’re Special

the-martian-matt-damonScientists are now finding evidence that there are a lot of apparently habitable planets out there, in a temperate zone in relation to their suns, where water is likely to form.

So why in the world (pun intended) aren’t we hearing or seeing signs of alien life when we point our radio telescopes at other star systems?  Our ability to search for evidence of life elsewhere has developed to the point where the lack of any contact has to be considered in any scientific theory about how life develops — and scientists are, in fact, doing just that.

The new theories posit that the world — our world — in fact played a key role.  They envision a “Gaian Bottleneck”: a kind of choke point that most alien life doesn’t survive.  While early, microbial life forms may have developed on those wet, rocky planets scientists are identifying just about everywhere, more complex life forms require planets with weather systems and atmospheric that are relatively stable.  The Gaian Bottleneck posits that such stability is lacking on many planets, and that changes in temperature or atmosphere killed off the alien life when it was in its fragile, early stages and unable to defend itself through evolution.  Thus, both Venus and Mars may have had early life forms, but the developmental arc of those planets — toward a high-pressure hot house on Venus, and a frigid, barren desert on Mars — killed them off.

Earth, though, somehow threaded the needle.  So, we’re special.

Of course, Earth’s example means some planets make it past any Gaian Bottleneck, so there may be advanced life out there — just not as much as you might think.

Venus On The Move

Venus is on the move today and tomorrow.  It’s traveling slowly across the face of the Sun, on a journey that astronomers call being “in transit” — as if Venus were hopping a subway to get from one side of the solar system to another.

These kind of astronomical events are very cool, because they happen so rarely.  There’s a “music of the spheres” sort of celestial harmony to Venus’ journey that reflects a special, highly unusual confluence of positioning of the Sun, Venus, and Earth.  It won’t happen again for 105 years.  By then, we hope, the European debt crisis will have been resolved.  In fact, some astrologers are saying that the transit of Venus might help to solve such problems.  It’s is supposed to herald in a new era of spiritual and technological revolution . . . or, it’s supposed to strongly accentuate feelings of love and hate.  With astrology, it always seems to be one or the other.

As with any solar celestial phenomenon, the news stories always caution people not to look directly at old Sol.  It’s hard to believe anyone would try to use the naked eye to check out the Venus transit, because Venus will be only a small speck against the enormous disk of the Sun.  You supposedly can see it safely by creating one of those pinhole-in-a-box projectors that the news stories typically mention in these circumstances.  I tried to make one of those devices when there was a solar eclipse during my childhood, and I gave up in frustration when it didn’t work.  This time, I’ll just rely on the photos, and in the meantime wish Venus well on her cross-town travel.