Facts About Mars: Life in the Habitable Zone
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Much to do has been made over the recent announcement of the discovery of a planet orbiting within the habitable zone of its host star. But a close reading of the report reveals little more is known about it beyond that basic fact. Just because a planet is close enough to its sun to be in a habitable zone is a far cry from the Goldilocks principle. Essentially this says that certain conditions have to be “just right” for life as we know it to exist. And what are the chances of self-aware, intelligent life on planets within habitable zones? They’re not nearly as good as some may hope. Take a look at what lies within our own sun’s habitable zone as an example.
Three planets and three moons orbit within the sun’s habitable zone. The closest of those to the sun is Venus. Habitable zone yes, but is Venus “just right” enough to support the possibility of life? No, it is not. Water cannot exist on the planet in liquid form, the atmosphere is toxic and temperatures are a steady 460o F., anytime of day and anywhere you go on the planet. If there is life on Venus, it’s not in any form we understand and there is no evidence that life has ever existed there.
How about the fourth planet? Here are a few facts about Mars. As far as life in the habitable zone goes, it is a bit more interesting, but only a bit. Although the planet’s average surface temperature is over 80o F. below zero, at certain times and in even more certain locations the temperature can reach a balmy 81o F. A little water is known to exist on the planet’s surface and there may be more underground. But that’s about as far as the Goldilocks principle goes on Mars. The planet’s atmosphere is too thin to resist the bombardment of ultraviolet radiation and atmospheric oxygen is almost non-existent. Mars may have been home to a more hospitable atmosphere at one time and there is evidence that liquid water once flowed more abundantly on the planet. But no evidence of life on Mars has ever been found.
How about either of the two moons that orbit Mars, Phobos and Deimos? Not even a chance. Both are no more than captured asteroids composed of rock. Beyond their existence within the sun’s habitable zone there is nothing about either one that remotely suggests any possibility of life.
How about our own moon? Indeed, of the six celestial objects being talked about here, the moon is second only to Earth at being the right distance from the sun…almost perfectly located really. But is there life on the moon? No atmosphere, only a trace of frozen water and absolutely no supporting evidence pretty much dashes any hope for lunar life. It’s a cold, dead place, and nothing suggests that it has ever been otherwise.
That leaves good old Earth. And lo and behold, every applicable condition for life exists on the third planet. Goldilocks would feel right at home here. The planet swarms with life and has done so for billions of years! And here’s a fact few consider when talking about the possibility of intelligent life on other planets. Although the conditions for life have been perfect on much of the Earth for so long, and even though billions of life forms, entire epochs of living creatures have come and gone on the planet, only one single species evolved into an intelligent organism. The next closest to us, chimps, dogs and dolphins, don’t even come close. A sobering thought indeed; so much for the habitable zone.
Here’s an article on Space.com about the recent discovery of a planet orbiting the habitable zone of its sun:
http://www.space.com/13821-nasa-kepler-alien-planets-habitable-zone.html.
Author: Charles Hooper is a freelance writer and the author of The Next American Revolution: How to Demand Congressional Reform NOW.
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