Life from space dust? Interstellar debris may transport living organisms between planets

EDINBURGH, Scotland — The origin of life on Earth has long been a subject of intense focus by scientists. One new theory developed by Scottish scientists suggests that life began from biological particles transported from planet to planet in streams of space dust.

In our solar system, bands of interplanetary dust drift between worlds, running into our atmosphere constantly. These interplanetary dust particles hit biological particles in our atmosphere hard enough, at times, to knock them into space, say researchers from the University of Edinburgh. This means that not only could our planet receive biological particles from other planets, but organisms from Early may be transported across the solar system. The process could allow microscopic organisms like bacteria to shift between numerous planet, or potentially even beyond.

Previous research pegged asteroids as the main vehicle of life between planets, but this study challenges that notion.

“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 leader Arjun Berera in a university media release. “The streaming of fast space dust is found throughout planetary systems and could be a common factor in proliferating life.”

For the study, researchers calculated how powerful streams of interplanetary debris behave when interacting with particles from the Earth’s atmosphere. These particles move fast, up to 70 kilometers per second — fast enough, the researchers concluded, to push organic particles that exist 150 kilometers above the Earth’s surface into space, where the particle stream can carry it to another planet or even beyond our solar system.

Some species of bacteria, plants, and even animals known as tardigrades are known to be able to survive in space. That leaves open the possibility that once dislodged from Earth’s atmosphere, these particles can reach another planet still alive.

The full study was published December 1, 2017 in the journal Astrobiology.