Researchers have suggested that fast-moving interplanetary dust could help life to travel to different worlds.
A new study by researchers from University of Edinburgh suggests that life on our planet might have originated from biological particles brought to Earth in streams of space dust from other worlds. There is also a possibility that life may have traveled from Earth to other worlds. The way the latter could have happened is that interplanetary dust streams could collide with biological particles with such speeds that these particles could have been knocked into space and traveled to far off worlds.
If such an event would have happened, it could have enabled bacteria and other forms of life that are able to survive the wrath of space to make their way from one planet in the solar system to another and perhaps beyond. The finding suggests that large asteroid impacts may not be the sole mechanism by which life could transfer between planets, as was previously thought.
Researchers calculated how powerful flows of space dust — which can move at up to 70 km a second — could collide with particles in our atmospheric system. They found that small particles existing at 150 km or higher above Earth’s surface could be knocked beyond the limit of Earth’s gravity by space dust and eventually reach other planets. The same mechanism could enable the exchange of atmospheric particles between distant planets.
Some bacteria, plants and small animals called tardigrades are known to be able to survive in space, so it is possible that such organisms — if present in Earth’s upper atmosphere — might collide with fast-moving space dust and withstand a journey to another planet.
Professor Arjun Berera, from the University of Edinburgh’s School of Physics and Astronomy, who led the study, said: “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. The streaming of fast space dust is found throughout planetary systems and could be a common factor in proliferating life.”
The study is published in Astrobiology.