The building blocks of life on Earth may be launching into space, perhaps seeding other worlds, according to a new study published in the journal Astrobiology and available in pre-print on arXiv.
Scientists from the University of Edinburgh (United Kingdom) have published a study in the journal Astrobiology in which they have proposed a hypothesis according to which life on planet Earth could have come from other planets in the cosmos.
According to calculations, the great flow of space dust that falls on the planet, in an amount of 105 kilograms per day and at speeds of 10 to 70 kilometers per second, is enough to boost, in the upper layers of the atmosphere, small living beings towards space.
This implies that life could be transferred from Earth to other places and that the same thing could happen, or have happened, in the opposite direction.
It is observed that hypervelocity space dust, which is continuously bombarding the Earth, creates immense momentum flows in the atmosphere. Some of this fast space dust inevitably will interact with the atmospheric system, transferring energy and moving particles around, with various possible consequences
“The hypervelocity space dust forms an immense and sustained flow in the atmosphere,” wrote the authors of the study, led by Arjun Berera. “For particles that form the thermosphere or above or reach there from the ground, if they collide with this space dust, they can be displaced, altered in form or carried off by incoming space dust.”
Berera believes that our planet’s organic material could have traveled as much as 30,000 light-years over the past few billion years, which is enough time to reach most parts of the galaxy.
According to Berera, this can have many consequences for the weather and the wind.
But, what is more interesting, in the opinion of the researcher at the University of Edinburgh, “is the possibility that this type of collision can give the particles of the atmosphere the escape velocity needed to escape from Earth’s gravity.”
In this way, the flow of small particles from space, whose masses range from one gram to one trillionth of a gram, would be like a space shuttle for living beings.
This means that resistant and extremely small organisms, such as bacteria, viruses, or tardigrades, could cross the space between solar systems or even beyond, thanks to the thrust of space dust, and perhaps survive their journey.
It also means that the impact of asteroids and comets would not be the only mechanism capable of transferring life between planets, as Svante August Arrhenius theory of panspermia indicates.
Experts note how “Hypervelocity space dust is a unique entity in planetary systems like our Solar System, which is able to go past and enter the atmosphere of planets, collect samples of those planets and deposit samples of other planets. The entire system of fast space dust in a planetary system thus contains the atoms, molecules and possibly even microbial life, from all the planets and provides a means to mix them up amongst the different planets.”
“The proposal that space dust collisions could propel organisms at enormous distances between planets opens some interesting perspectives on how life and the atmospheres of planets originated,” Berera said in a statement.
“The currents of space dust present in planetary systems could be a common factor in the proliferation of life.”
The next decades of space exploration through powerful telescopes will perhaps clarify numerous questions and whether or not, hypervelocity space dust may have acted as a transport system for microbial life spreading across space.