There was incredible news from Mars yesterday. No, not the water ice. That was last week, and actually was widely expected. It's great to have the theories confirmed, but they were thought to be pretty solid anyway; and they were.
I'm talking about the soil analysis they're doing, cooking little bits of Mars in tiny laboratory ovens and having sensors sniff what wafts out.( http://phoenix.lpl.arizona.edu/ )
“We basically have found what appears to be the requirements, the nutrients, to support life whether past, present or future,” said Samuel P. Kounaves of Tufts University, who is leading the chemical analysis… “The sort of soil you have there is the type of soil you’d probably have in your backyard.”
In short: the building blocks of Mars turn out to be pretty much the same as Earth's. If Martian soil had been toxic or wildly different from Earth's, it would have toppled several theories, and made our position in the Universe all the lonelier: Anything that points to Earth being unique and different makes it that less likely that other Earths would exist.
But when we find that Earth isn't so unique, it makes it all the more likely that there'd be life elsewhere too.
Now consider this: We've barely started hunting but so far we've already discovered, 259 other stars that have planets circling them; and we've found 303 alien planets in all around those other stars. (http://planetquest.jpl.nasa.gov/ ) New planets and planetary systems are announced every few days, it seems, and detection has gotten so good that scientists are starting to be able to see planets down into the size range of Earth. (http://www.dailymail.co.uk/sciencetech/article-450467/Found-20-light-years-away-New-Earth.html ) Planets are turning out to be absolutely commonplace.
Our non-unique solar system with its non-unique chemistry produced life least once (here on Earth); maybe twice, depending on the details of Mars' past; and maybe even a third and fourth time if theories about some of the large moons of the gas giant planets prove correct.
So imagine how filled with life the universe is likely to be.
That's what's changing the way I look at the night sky.
Next time you look at the stars, realize that you're looking at a universe that filled not only with uncountable stars, but an even larger number of planets--- far more planets than anyone imagined even a few short years ago. It's odds-on that there are many, many other "Earths" out there.
So as you look up, there's a real chance that somewhere out there, alien eyes are looking back at you, searching the distant sky, and wondering if you exist.
More?
Martian soil appears able to support life
http://www.reuters.com/article/wtMostRead/idUSN2634952620080626
Mars Soil 'Friendly' To Life, Tests Show
http://www.washingtonpost.com/wp-dyn/content/article/2008/06/26/AR2008062603578.html?hpid=moreheadlines
Tests show Martian soil can support life
http://www.computerworld.com/action/article.do?command=viewArticleBasic&taxonomyId=11&articleId=9104018&intsrc=hm_topic
Mars lab finds nutrient minerals plants use
http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2008/06/27/MN3P11FNT9.DTL
Mars soil capable of sustaining plant life
http://www.latimes.com/news/nationworld/nation/la-sci-phoenix27-2008jun27,0,147368.story
Alkaline Soil Sample From Mars Reveals Presence of Nutrients for Plants to Grow http://www.nytimes.com/2008/06/27/science/space/27MARS.html?_r=1&ref=us&oref=slogin
Wet chemistry on the Martian surface
http://arstechnica.com/journals/science.ars/2008/06/26/wet-chemistry-on-the-martian-surface
I have never believed that the Earth is entirely unique in the Universe, but I do not think that life as we know it is common-place either. It makes sense that the building blocks of life should be fairly evenly distributed throughout the Universe, although I think one block is missing on Mars: A magnetic field to shield the planet from Solar radiation.
ReplyDeleteWe have found that life is persistent on the Earth and develops in extreme conditions of cold, heat, and even dark. I have not seen any evidence that life has found a way to overcome the ravages of radiation, so even though a planet may have nearly all the required building blocks of life, if it does not have a planetary magnetic field, life may fail to develop.
Another building block of life may prove to be a fairly circular planetary orbit resulting in a relatively consistent ambient temperature. Even though we have observed that life can survive in conditions of extreme heat or cold, I question its ability to persist in an environment alternating between these two extremes.
With all this said, I believe it is inevitable that planets orbiting other stars harbor intelligent life in our Galaxy (and the Universe). There are simply too many for ours to be the only one. I just do not think that intelligent life is all that common, or perhaps I still cling to the notion that life is something special, and that each individual is unique, and therefore important.