New Horizons spacecraft flyby of Pluto in July 2015 has returned new understanding of the surface topography of the planet, which reveals greater details of icy crusts previously postulated to exist. Ideas concerning the possibility of life on the icy planet have surfaced and will be discussed here.
Surface temperature at Pluto is very cold, and it only has a thin atmosphere. Thus, it is unlikely for microorganisms to survive the icy temperatures on the surface of Pluto. But, could life exist underneath the icy crust, for example, in a liquid ocean? The answer is possible, but for life to exist in Pluto, it must have a heat source stronger than the low intensity solar radiation the planet receives from the Sun.
All life needs energy to survive. Hence, a heat source, likely to be geothermal in origin, must exist on Pluto in order for the faraway planet to support microbial life. Such a heat source would help melt the ice into a liquid suitable for microorganisms to survive. Additionally, thermal energy is also necessary to power the many chemical reactions requisite for biological processes to enable a living cell to move, metabolize and remove its degradation products in an iterative fashion.
Hence, while life is possible on Pluto, a heat source must be present in its rocky core to allow liquid water to exist underneath its icy crust. Such a thermal source would serve two purposes: (i) a source of heat to keep the fluid medium in which life has to exist, and (ii) thermal energy to power all necessary chemical reactions that define biological life the way we understand it. Given the close to liquid nitrogen temperature (-196 oC) of Pluto’s surface, it is very unlikely for microbial life to exist on the surface. However, if a geothermal energy source is present within the planet that enables a liquid ocean to exist below the icy crust, microbial life could survive on the icy planet.
Category: biochemistry, space exploration, cell biology, exoplanets,
Tags: liquid ocean, geothermal energy, chemical reactions, Pluto, microbial life, rocky planet, crust,