Scientists have discovered that the exoplanets, resembling our own Neptune, have a potentially habitable core. Under right conditions, these gas planets could convert to life-supporting environments. Researchers from the University of Washington have predicted when and where gas planets may become habitable, with the help of computer models. The research has been published in the journal Astrobiology.
Milky Way galaxy has a large number of Class M dwarf stars. Researchers opine that those planets which orbit their stars at distances which allow the formation of liquid water on the surfaces are likely to support alien life. It is called as Goldilocks zone or habitable zone around an alien star. Exoplanets that orbit around class M dwarfs must be closer to their stars so that they receive the warmth required for the presence of liquid water on the surface.
Researchers believe that Neptune-like planets, formed far from their parent star, may eventually succumb to the forces of their sun and migrate due to tidal forces. Rodrigo Luger from the University of Washington commented “They are initially freezing cold, inhospitable worlds. But planets need not always remain in place. Alongside other processes, tidal forces can induce inward planet migration.” As these planets reach closer to their parent star, their thick gases are pushed away by the powerful streams of solar radiation, resulting in the formation of habitable evaporated cores.
Earth also experiences tidal forces. Luger said “Luckily, on Earth it’s really only the water in the oceans that gets distorted, and only by a few feet. But close-in planets, like those in the habitable zones of M dwarfs, experience much stronger tidal forces.” Bodies encountering strong tidal forces experience flexing and they become egg-shaped. The process also creates friction which helps in warming up the planet.
Volcanism is also the outcome of tidal forces due to which large quantities of core material are released into the atmosphere of these gas planets. The phenomenon produces a greenhouse effect which warms the planet further. But in case this process continues, the oceans on the planet would evaporate making the planet uninhabitable. However, several transformations are required on these planets before even the primitive life originates and thrives.