Researchers 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.
About 3.8 billion years ago existence first sprang up but scientists have been unable to figure out how it started.
However, the mystery may have just been cracked by scientists who believe life was delivered here from deep space.
British boffins have come up with a new theory on how existence on Earth arose, and suggest it could be down to the intrepid alien bugs.
The team calculated minuscule bio-particles could be hitching a ride on space dust which travels through the cosmos at 70 kilometres per second.
These tiny specks could then end up on planets, like Earth, where they landed and began the process of evolution.
Bio-particles could have also ended up on other planets inside our solar system, the researchers state.
Previous research has found that micro-animals known as tardigrades can survive in the harsh conditions of space, so the suggestion is certainly possible.
Study leader Professor Arjun Berera, from the University of Edinburgh’s School of Physics and Astronomy, 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 team also suggest that bio-particles could be taken away from Earth and help seed life elsewhere in the universe.
A statement from the University of Edinburgh’s School of Physics and Astronomy read: “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.”
The British Journal Editors and Wire Services