Nov. 20 (UPI) -- Astrobiologists suggest the building blocks of life could be carried between worlds by streams of space dust. In fact, life-giving dust may have delivered the biological particles that first sparked life on Earth.
Researchers at the University of Edinburgh argue interplanetary dust could collide with tiny organisms or biological particles in Earth's upper atmosphere with enough energy to kick them into space. These organisms or life-bearing particles could be carried from planet to planet, or possibly even to another solar system.
Scientists detailed their hypothesis in a new study, recently published in the journal Astrobiology.
Previous studies have shown a variety of microorganisms can survive in space, including the small, resilient micro-animals known as tardigrades, or water bears. The outside and inside of the International Space Station, for example, host diverse microbial communities.
Edinburgh scientists calculated that small particles suspended more than 93 miles above Earth's surface could be knocked into space by dust streams traveling 43 miles per second. The same mechanics could potentially propel a water bear into interplanetary space.
"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," Arjun Berera, professor of physics and astronomy at Edinburgh, said in a news release. "The streaming of fast space dust is found throughout planetary systems and could be a common factor in proliferating life."