{"id":2416,"date":"2010-06-06T15:29:42","date_gmt":"2010-06-06T20:29:42","guid":{"rendered":"http:\/\/www.starshipnivan.com\/blog\/?p=2416"},"modified":"2010-06-08T14:49:56","modified_gmt":"2010-06-08T19:49:56","slug":"the-sirens-of-titan","status":"publish","type":"post","link":"https:\/\/starshipnivan.com\/blog\/?p=2416","title":{"rendered":"The Sirens of Titan: Alien Life?"},"content":{"rendered":"<p>(Title borrowed from Kurt Vonnegut)<\/p>\n<p><a href=\"http:\/\/www.starshipnivan.com\/blog\/wp-content\/uploads\/2010\/06\/Titan-Craig-Attebery-N.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-2414\" title=\"Titan Craig Attebery N\" src=\"http:\/\/www.starshipnivan.com\/blog\/wp-content\/uploads\/2010\/06\/Titan-Craig-Attebery-N.jpg\" alt=\"\" width=\"451\" height=\"338\" srcset=\"https:\/\/starshipnivan.com\/blog\/wp-content\/uploads\/2010\/06\/Titan-Craig-Attebery-N.jpg 640w, https:\/\/starshipnivan.com\/blog\/wp-content\/uploads\/2010\/06\/Titan-Craig-Attebery-N-300x225.jpg 300w\" sizes=\"auto, (max-width: 451px) 100vw, 451px\" \/><\/a><\/p>\n<p>In the novel and film <em>2010<\/em>, when the Monolith builders force Jupiter into nuclear ignition they also program poor put-upon HAL to broadcast, non-stop &#8220;All these worlds are yours except Europa. Attempt no landings there.&#8221;<\/p>\n<p>Arthur C. Clarke was deemed uncannily prescient when he wrote this, because many astrobiologists believe that life may exist under Europa\u2019s thick ice crust: the moon harbors an underground water ocean and has geothermal energy courtesy of its huge planet.  But recent news from the Cassini-Huygens mission could prove the prophet wrong.  Before we encounter life on Europa, we may find it on Titan.<\/p>\n<p>The Cassini data essentially show complex surface chemistry, as the Voyager data did for Mars.  They also show mysterious absences of items expected to be abundant, given Titan\u2019s specifics \u2013 acetylene and hydrogen in particular.  Such results always carry the cautionary sentence that \u201cnon-biogenic processes yet unknown\u201d could cause these anomalies.  But organisms feeding on the missing chemicals is definitely on the list of these processes, something that several astrobiologists (Chris McKay, Derek Schulze-Makuch, David Grinspoon) suggested five years ago by speculating that acetylene would be tasty to Titanian life.<\/p>\n<p>Titan, unlike bone-dry Mars, has enormous lakes \u2013 although they contain liquid hydrocarbons, rather than water.  The lightest in that family (methane and ethane) are poor solvents because they\u2019re non-polar, unlike water and ammonia.  Nevertheless, they do act as solvents for the rich organic soup churned by Titan\u2019s thick atmosphere of ammonia and methane (Carl Sagan\u2019s \u201ctholins\u201d, from the Hellenic word for murky).  And although chemical reactions will be slow in Titan\u2019s ambient temperature of \u2013190 Celsius (room temperature is 24 Celsius), all bets are off once enzymes are involved.<\/p>\n<p>If we can conclude definitively that there is life on Titan, we will have walked one step further to the right of the Drake equation.  We share material with Mars by meteorite exchange, so any life that existed or still exists there may have shared its beginnings with us.  There can be no such ambiguity for Titan, given its distance and conditions.  Whatever we find there, from bacteria to placidly grazing hydrogen balloons, it will be the product of an independent genesis.  And it will be very different from us, finally making it possible to rigorously determine which aspects of life are parochial and which are universal.<\/p>\n<p><a href=\"http:\/\/www.starshipnivan.com\/blog\/wp-content\/uploads\/2010\/06\/Ammonia-Grossman.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-2415 alignnone\" title=\"Ammonia Grossman\" src=\"http:\/\/www.starshipnivan.com\/blog\/wp-content\/uploads\/2010\/06\/Ammonia-Grossman.jpg\" alt=\"\" width=\"443\" height=\"292\" srcset=\"https:\/\/starshipnivan.com\/blog\/wp-content\/uploads\/2010\/06\/Ammonia-Grossman.jpg 547w, https:\/\/starshipnivan.com\/blog\/wp-content\/uploads\/2010\/06\/Ammonia-Grossman-300x197.jpg 300w\" sizes=\"auto, (max-width: 443px) 100vw, 443px\" \/><\/a><\/p>\n<p>This brings us full circle to HAL\u2019s warning.  If life exists elsewhere in the solar system, it will be both a boon and a burden.  Such a discovery will give a major boost to astrobiology, which will finally have a legitimate topic to explore beyond the armchair vaporings of famous physicists \u2013 and to crewed space exploration, beyond the depressing and trivial prospect of sending more people in fungus-infested tincans into low terrestrial orbit.<\/p>\n<p>At the same time,<a href=\"http:\/\/io9.com\/5526680\/well-only-find-extraterrestrial-life-if-we-know-what-were-looking-for\"> as I wrote elsewhere<\/a>, we may destroy alien life even if we are careful.  Such an outcome will deprive us of precious, irrecoverable knowledge that will help us make sense of our universe and our own planet, even if the new life consists entirely of bacteria (to say nothing of the moral equivalent of genocide if it\u2019s more advanced than that).  It may be that none of these worlds are ours, except for us exploring them and becoming their stewards.<\/p>\n<p>Note: The article is <a href=\"http:\/\/www.huffingtonpost.com\/athena-andreadis-phd\/the-sirens-of-titan-alien_b_602256.html\">now also<\/a> on Huffington Post,<em> sans<\/em> images and references.<\/p>\n<p>Images: <em>Huygens on Titan<\/em>, Craig Attebery (NASA); &#8220;Ammonia!\u00a0 Ammonia!&#8221; by Robert Grossman, <em>The New Yorker<\/em>.<\/p>\n<p>References:<\/p>\n<p>C. P. McKay and H. D. Smith (2005).  Possibilities for methanogenic life in liquid methane on the surface of Titan. Icarus 178, 274-276.<\/p>\n<p>Schulze-Makuch, D., and D.H. Grinspoon (2005) Biologically enhanced  energy and carbon cycling on Titan? Astrobiology 5, 560\u2013564.<\/p>\n<p>D. F. Strobel (2010).  Molecular hydrogen in Titan\u2019s atmosphere: Implications of the measured tropospheric and thermospheric mole fractions.  Icarus, in press.<\/p>\n<p>R. N. Clark et al (2010). Detection and Mapping of Hydrocarbon Deposits on Titan. J. Geophys. Res., in press.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>(Title borrowed from Kurt Vonnegut) In the novel and film 2010, when the Monolith builders force Jupiter into nuclear ignition they also program poor put-upon HAL to broadcast, non-stop &#8220;All these worlds are yours except Europa. Attempt no landings there.&#8221; Arthur C. Clarke was deemed uncannily prescient when he wrote this, because many astrobiologists believe [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10,5],"tags":[],"class_list":["post-2416","post","type-post","status-publish","format-standard","hentry","category-science","category-space-exploration"],"_links":{"self":[{"href":"https:\/\/starshipnivan.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/2416","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/starshipnivan.com\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/starshipnivan.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/starshipnivan.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/starshipnivan.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2416"}],"version-history":[{"count":0,"href":"https:\/\/starshipnivan.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/2416\/revisions"}],"wp:attachment":[{"href":"https:\/\/starshipnivan.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2416"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starshipnivan.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2416"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starshipnivan.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2416"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}