The Blog's Focus
Why such discourses? As we move further into the 21rst century, these are topics will gain in importance as we continue to detect more exoplanets, to discover how widespread the building blocks of life are in the universe, and to expand the definition of life. The chances of our detecting life on another planet outside our solar system increase as our technology and techniques increase in sophistication (for example, the ability to analyze the atmosphere of a planet light years away).
Thus, the questions of whether life exists outside of the Earth take on new impetus. For with new life comes the possibility of new sentient life. What would that extrasolar sentient life be like? Pondering this question is not a mater of mere idle speculation. It goes beyond grown up fairy tales. Just as the examination of other planets in our solar system help us to understand our own planet, the examination of life on other planets may help us to understand ourselves. This meditation on other life affects meditation upon our own life.
As T.S. Eliot wrote in his poem "Little Gidding":
And the end of all our exploringWe need to explore, to learn.
Will be to arrive where we started
And know the place for the first time.
Additionally, such contemplations can help us prepare for when we discover alien biologies, psychologies, societies, technologies and theologies.
Brief Background to the Issues
It seems that every few weeks there is another discovery of an exoplanet. As of October 2007 over 200 have been found. As more new telescopes, both on the ground and in space, having greater viewing power than the Hubble Space telescope come on line, the discoveries have not only begun to pick up speed, but ever smaller planets are being discovered as well.
In 2006 the ESA launched the COROT space telescope, designed to detect planets not much larger than the Earth. It began searching in Feb 2007 and has already found additional planets. In 2009 NASA plans to launch the Kepler space telescope, also designed to search for extrasolar planets. The James Webb Space Telescope, with a possible launch date of 2013, will be the replacement for Hubble, with greater observing powers than its predecessor. DARWIN, an European Space Agency proposed space telescope with a possible launch date of 2015, will be able to detect directly an earth sized extrasolar planet - with enough detail that we may even be able to determine if there is carbon-based life on it. In 2005, Dr. Webster Cash of the Univ of Colorado at Boulder, had his New Worlds Imager project funded by the NASA Institute for Advanced Concepts (NIAC). The project plans to build a large pinhole camera in Earth orbit capable of detecting Earth sized extrasolar planets up to 32 light years away. So far there is no proposed launch date. Even more extrasolar planet mission exist or are planned: for more information visit the Jet Propulsion Laboratory's "Planet Quest: Missions" page.
From a different angle, the newly powered up Allen Telescope Array, a SETI project, will increase the chances of detecting signals from extrasolar civilizations (those who have advanced to a technological level).
The next logical question, though, is how many extrasolar planets can harbor life? First, the building blocks of life, from simple chemicals like Carbon and water to more complex amino acids, are found throughout space in interstellar clouds, planetary disks, meteors and comets, and the atmosphere of exoplanets, as being expelled into space by dying stars. Some even theorize that is how life began on Earth - it was seeded from the heavens. Second, planets are being found (whole or forming) within the "habitable zones" of their parent stars (basically, the zone around a star where liquid water can exist) - a recent one is the fifth planet to be discovered around 55 Cancri.
Around the sun, the Habitable Zone is 0.95 to 1.37 A.U. However, life could possibly exist beyond this zone: scientists are now contemplating the possibility of life existing on Europa (there is a thin atmosphere of oxygen and quite possible a liquid ocean underneath the planet covering ice sheet). And finally, as we keep finding on Earth, life is tenacious - we are finding life everywhere on this planet, under an increasing range of conditions, including extreme conditions of no oxygen, boiling water, and frozen ice.
Because life can thrive under a wide range of conditions, it is most likely that alien life does not need a Earth duplicate on which to form and thrive, and thus it will be an astronomically minute chance that alien life will be duplicates of Earth life. There is a vast range of variables that can affect the direction alien biology takes, which in turn can affect the alien's psychology, society, technology, and theologies.
I don't want this blog to be one-sided. Please feel free to leave comments, whether to challenge or to support a speculation, or to suggest other references and resources. It is my hope this blog can be beneficial to its readers, including amateur philosophers, students looking for essay topics, and science fiction writers looking for ideas to stimulate writing, as well as for space science and/or science fiction fans.
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"ATA." SETI Institute. 2007. Web. 30 October 2007. <http://www.seti.org/seti/projects/ata/>.
"Europa, a Continuing Story of Discovery." Project Galileo. NASA. Web. 30 October 2007. <http://www2.jpl.nasa.gov/galileo/europa/>.
"Extrasolar planet." Wikipedia, The Free Encyclopedia. 4 Nov 2007, 07:02 UTC. Wikimedia Foundation, Inc. Web. 4 Nov 2007. <http://en.wikipedia.org/w/index.php?title=Extrasolar_planet&oldid=169111401>.
Jet Propulsion Laboratory. "Planet Quest: Missions." NASA. Web. 30 October 2007. <http://planetquest.jpl.nasa.gov/missions/missions_index.cfm>.
Johns Hopkins University. "Earth-like Planet Forming In Nearby Star System, Astronomers Believe." ScienceDaily. 4 October 2007. Web. 30 October 2007. <http://www.sciencedaily.com/releases/2007/10/071003130744.htm>.
NASA Goddard Space Flight Center. "Cornucopia Of Earth-sized Planets Modeled By NASA." ScienceDaily. 25 September 2007. 30 October 2007. <http://www.sciencedaily.com/releases/2007/09/070924132510.htm>.
NASA/Marshall Space Flight Center. "NASA Scientist Discovers New Species Of Organism In Mars-like Environment." ScienceDaily. 31 July 2003. Web. 30 October 2007 <http://www.sciencedaily.com/releases/2003/07/030731081613.htm>.
"Notes for star 55 Cnr [55 Cancri]" Extrasolar Planets Encyclopedia. Web. 4 November 2007. <http://exoplanet.eu/star.php?st=55+Cnc>.
University of California, Los Angeles. "Polluted Dead Star Indicates Planets Like Earth May Have Formed Around Other Stars." ScienceDaily. 17 August 2007. Web. 30 October 2007 <http://www.sciencedaily.com/releases/2007/08/070816214820.htm>.
University of Liège. "Astronomers Detect Shadow Of Water World In Front Of Nearby Star." ScienceDaily 16 May 2007. Web. 30. October 2007 <http://www.sciencedaily.com/releases/2007/05/070516151053.htm>.