Hundreds of thousand billion planets could be floating nomadically through the galaxy Theory would explain the unexplained ‘missing matter’ of the Milky Way Planets would cross the galaxy, picking up living cells as they floated through cosmic dust
Researchers have come up with a startling suggestion for how life could propagate across our galaxy. Identifying the mathematical hole between the expected mass of our galaxy – The Milky Way – and what is observed, they theorise that there are billions and billions of ‘nomadic’ planets, unaffiliated to any particular star, floating through the darkness of space. The scientists from the Astrobiology department at the University of Buckingham have proposed that these planets originated in the early Universe, within a few million years of the Big Bang, and that they make up most of the so-called ‘missing mass’. The scientists calculate that these planetary body would cross the inner solar system every 25 million years on average – and during each transit, dust from the neighbourhood, including living cells, would become implanted at its surface. These free-floating planets would then end up mixing harbouring the living cells with the planet’s own make-up, and life could spread by this method on a galaxy-wide scale. Since 1995, when the first extrasolar planet was reported, interest in searching for planets has reached a feverish pitch. The 750 or so detections of exo-planets are all of planets orbiting stars, and very few, if any, have been deemed potential candidates for life.
The possibility of a much larger number of planets was first suggested in earlier studies where the effects of gravitational lensing of distant quasars by intervening planet-sized bodies were measured. Recently several groups of investigators have suggested that a few billion such objects could exist in the galaxy.