High velocity space dust is continuously bombarding the Earth and its atmosphere. Streams of this space dust can inevitably collide and interact with atmospheric particles to facilitate their ejection out into space. A professor from the University of Edinburgh has now proposed mechanisms that would enable such collisions, allowing the possibility of transporting microbial life and organic molecules across the universe.
According to the paper, published in the journal Astrobiology, powerful flows of space dust can travel up to 70 km/second, or 252,000 km/hour. In calculations that take into account gravitational acceleration, particle size and surface temperatures, the study estimates that particles that lie at least 150 km above the Earth’s surface are susceptible to being knocked off into space during collisions.
Various studies have shown that bacteria can be pushed up from the surface to the atmosphere through events such as volcanic eruptions and hurricanes. Bacteria have been detected as high up as 40 km, and clouds as high as 100 km harbor small particle matters.
Microbial survivability is also well documented. Thermophiles can survive temperatures of 400K and others such as tardigrades can survive liquid nitrogen temperatures as low 77K. Bacterial spores left on the exterior of the International Space Station at an altitude of 400 km have even survived 1.5 years with no water and with direct exposure to radiation.
According to the study, the mechanism proposed in this paper for propelling small particles into space could provide a universal mechanism in initiating panspermia, the interplanetary seeding of life.
"The proposition that space dust collisions could propel organisms over enormous distances between planets raises some exciting prospects of how life and the atmospheres of planets originated,” says study author, Arjun Berera. “The streaming of fast space dust is found throughout planetary systems and could be a common factor in proliferating life."