ahar...@earthlink.net Fascinating stuff! Subject: Minerals and life
> Hi: > The March 2010 Scientific American includes the article: > > Evolution of Minerals; March 2010; by Robert M. Hazen; 8 Page(s) > > The article indicates that in the early stages of Earth's history there > were only about 250 mineral compounds. This is what they estimate most > planet / moon-type objects have if they don't have processes that will > help produce additional compounds. They estimate that even assuming Mars > once had seas that dried up, it is unlikely to have more than 500 > compounds. Venus' more active geological forces, atmosphere, etc. probably > have produced more. Similarly, Earth's geological, atmospheric and oceanic > forces produced additional compounds even before life had much impact. > However, after plants had increased the oxygen content of the air, another > 1000+ compounds were produced. They estimate that later life processes > lead to about 2000 more compounds - so that Earth now has about 4400. > > The article suggests that scientists might use the presence of large > numbers of mineral compounds on other worlds as an indicator of past or > present life there. > > The information in the article suggests that other worlds without past or > present life will have limited numbers of mineral compounds. It occurred > to me this may have implications for human colonization of other worlds. > Part of the reason geological and life processes are needed to create > additional compounds is that without those forces some chemical elements > are scattered too widely to form useful concentrations. Other worlds with > few compounds and limited concentrations of certain elements for mining > could prevent adequate availability of natural resources needed for a > technological society. > > Of course, humans could avoid life-less worlds and try to colonize worlds > with life. However, planets with a robust enough ecology to produce a > native intelligent species aren't appropriate for human colonization. > Planets with life (but no intelligent life) may be the best option, > although the native life more likely than not won't be healthy and > nutritious for Earth life. We can import Earth plants and animals, but the > native life will presumably be better adapted to the specifics of that > planet. Colonization might be more involved than previously thought. > > Other articles in the March Scientific American include: > > Heavy Brows, High Art; March 2010; by Charles Q. Choi; 2 Page(s) > Were Neandertals our mental equals? > > Dark Side of Black Holes; March 2010; by Charles Q. Choi; 3 Page(s) > Dark matter could explain the early universe's giant black holes > > The Moon That Would Be A Planet; March 2010; by Ralph Lorenz and > Christophe Sotin; 8 Page(s) > Titan, Saturn's largest natural satellite, scarcely deserves to be a > called a mere moon. It has an atmosphere thicker than Earth's and a > surface that is almost as varied > > The Brain's Dark Energy; March 2010; by Marcus E. Raichle; 6 Page(s) > Brain regions active when our minds wander may hold a key to understanding > neurological disorders and even consciousness itself > > Fusion's False Dawn; March 2010; by Ben Knight; 8 Page(s) > Scientists have long dreamed of harnessing nuclear fusion—the power plant > of the stars—for a safe, clean and virtually unlimited energy supply. Even > as a historic milestone nears, skeptics question whether a working reactor > will ever be possible > > Climate Change: A Controlled Experiment; March 2010; by Stan D. > Wullschleger and Maya Strahl; 6 Page(s) > Scientists have carefully manipulated grasslands and forests to see how > precipitation, carbon dioxide and temperature changes affect the > biosphere, allowing them to forecast the future > ------------------------------------ Post your SciFiNoir Profile at http://groups.yahoo.com/group/scifinoir2/app/peoplemap2/entry/add?fmvn=mapYahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/scifinoir2/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/scifinoir2/join (Yahoo! ID required) <*> To change settings via email: scifinoir2-dig...@yahoogroups.com scifinoir2-fullfeatu...@yahoogroups.com <*> To unsubscribe from this group, send an email to: scifinoir2-unsubscr...@yahoogroups.com <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
