Travelling in a Flow of Stardust
From where do we come, and how did we get here? What if, we were brought to Earth in ‘vehicles’ made of stars? According to a team of scientists from the University of Edinburgh, this might be a possibility. The researchers suggest that life might have started with organisms that have come from faraway worlds, travelling in fast-moving space dust; the latter, also known as cosmic dust, exists as particles ranging in size from 0.1 µm to a few molecules to 0.1 mm, and some of it is thought to be leftovers from stars (stardust). This flow of interplanetary dust might also go the opposite way: it might have taken living things from our very own Earth to other planets.
How Does Space Dust Carry Life?
Theoretically, a stream of space dust would enter the Earth’s atmosphere where it would collide with biological particles with great energy such that would propel them into space. This would allow life forms like bacteria to move from one planet to another in the solar system; the researchers add that organisms might even be transported beyond. This mode of transfer of life would supplement the other hypothetical mechanism that suggests life came to be on our planet through impacts from massive asteroids.
It all started when the researchers analysed data about powerful streams of space dust, those travelling at a maximum speed of 70 km a second. They calculated how intense flows like these could come into collision with particles in our atmosphere. Their findings show that cosmic dust could push small particles located at 150 km or higher from the surface of the Earth to regions beyond the planet’s gravity into space, and eventually to other planets. This mechanism would have also accommodated for the exchange of atmospheric particles from planet to planet. But, can living organisms survive this journey?
Animals Surviving in Space
The concept of life journeying through space to worlds beyond their own is not that far-fetched given that some bacteria, plants, and animals (like the very resilient tardigrade) are known to resist the extreme conditions in space. So, if these types of organisms were found in the upper atmosphere of our planet, they might have been forced out into space to another planet through collisions with fast-moving space dust.
“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,” says lead author Arjun Berera from University of Edinburgh’s School of Physics and Astronomy.
Suddenly, travelling through worlds seems no more something of fantasy and science fiction.