The Possibility for Panspermia in the Galaxy by Means of Planetary Dust Grains

Abstract

Under the assumption that planetary dust particles can escape from the gravitational attraction of a planet, we consider the possibility of the dust grains leaving the star’s system by means of radiation pressure. By taking the typical dust parameters into account, we consider their dynamics and show that they can reach the deep space, taking part in panspermia. It has been shown that, during 5 billion years, the dust grains will reach 10 5 stellar systems, and by taking the Drake equation into account, it has been shown that the whole galaxy will be full of planetary dust particles. It has been found that dust grains can be trapped within HI and HII clouds of the interstellar medium, suggesting that these regions may harbor not only the building blocks of life but also complex molecules associated with life. We have also emphasized two key factors that hinder the preservation of life within interstellar clouds: (a) the interaction of dust grains with extremely hot regions, which leads to the complete ionization and destruction of complex molecules, and (b) the lack of definitive knowledge regarding the long-term survival of bacteria in the vacuum.