in recent years the search for life beyond our planet has focused on finding places with conditions that are ‘earth like’, so as to emulate our own planet, which we know can support life however, scientists have now proposed that some worlds might be able to host life ‘not as we know it’ that thrives not on water, but on other chemicals specifically, they looked at saturn’s moon titan, which has seas of liquid methane rather than water, and they it could harbour methane based, oxygen free forms of life cornell university scientists in new york have proposed a new type of life called an azotosome, it would survive on liquid methane rather than water   so it could live on titan shown is an illustration of a nine nanometre azotosome, the size of a virus, with a piece of the membrane cut away to show the hollow interior  the fascinating research by scientists at cornell university in new york suggests that life in the universe may be abundant in more places than thought the life they propose, called an azotosome, would be composed of small organic nitrogen compounds and be capable of functioning in liquid methane temperatures of  180°c ( 292°f) no life on earth is known to be able to survive in similar conditions ‘ours is the first concrete blueprint of life not as we know it,’ said graduate student james stevenson, first author of the research life on our planet relies on a permeable water based exterior   a vesicle or liposome   that houses the organic matter of every cell as no life on earth can survive without water, astronomers have been looking for alien life in habitable zones of stars where liquid water can exist   it is not too hot, and not too cold but if cells could be based on methane, rather than water, they could survive in much colder climates, as methane has a much lower melting point a study in november 2014 argued that alien species could exist on planets that contain an exotic substance known as 'supercritical' carbon dioxide, rather than water this type of co2 is created when liquids and gases reach their temperature and pressure thresholds, creating a supercritical fluid that has features of both a liquid and gas carbon dioxide becomes supercritical when its temperature exceeds 305 degrees kelvin (32°c) and its pressure goes beyond 729 the standard atmosphere at sea level on earth, it's increasingly used in application such as dry cleaning or to sterilise medical equipment, but astrobiologists at washington state university believe it could also be capable of sustaining life study co author professor schulze makuch and his team compared enzymes in carbon dioxide and in water, and found that they were more stable in supercritical co2 the life proposed by the scientists would be composed of small organic nitrogen compounds and be capable of functioning in liquid methane temperatures of  180°c ( 292°f) this means it could survive on the surface of titan (illustration shown), meaning more worlds might be habitable than we thought  the theoretical azotosome life form is made from nitrogen, carbon and hydrogen molecules   all of which are known to exist in the cryogenic seas of titan however, it shows the same stability and flexibility as comparable life on earth and interestingly, to create the structures, the scientists also envision the cells could use a compound called acrylonitrile, which is a strong barrier to decomposition acrylonitrile is a colourless, poisonous, liquid organic compound use in the manufacture of acrylic fibres and thermoplastics on earth   and it is also present in titan’s atmosphere chemical engineer dr paulette clancy said the the next step is to try and demonstrate how these cells would behave in the methane environment this includes how they might reproduce and metabolise with their oxygen free, methane based cells from left to right are graduate student james stevenson, astronomer jonathan lunine and chemical engineer paulette clancy, with a cassini image of titan in the foreground of saturn, and an azotosome, the theorized cell membrane on titan, shown on the right 
james stevenson moon titan first cornell university new york saturn
cornell university scientists in new york have proposed a new type of life  called an azotosome it would survive on liquid methane rather than water  this means it could live on the surface of saturn's moon titan  and it may also mean more places are habitable than we thought  it's the first proof for 'life not as we know it,’ said student james stevenson 