Looking for life in unlikely places: reasons why planets may not be the best places to look for life

Abstract

A new method is proposed to search for extraterrestrial life adapted to cold environments far from the Sun. To keep warm, using the light from a distant sun, any life-form must grow a system of optical concentrators, lenses or mirrors, to focus sunlight on to its vital parts. Any light not absorbed, or any heat radiation emitted from the vital parts, will be focused by the optical concentrators into a narrow beam pointing back towards the sun. To search for such life-forms, we should scan the sky with optical and infrared telescopes pointing directly away from the Sun. Any living vegetation will be seen as a bright patch in strong contrast to its dark surroundings, like the eyes of a nocturnal animal caught in the headlights of a car. This method of search may be used either with space-based or with ground-based telescopes. Examples of places where the method would work well are the surfaces of Europa, Trojan asteroids or Kuiper Belt objects. Any life-form that adapted successfully to a vacuum environment would be likely to spread widely over objects with icy surfaces in the outer regions of the solar system.