Researchers in Hawaii and California have found that interplanetary dust particles can act as seeds of life, delivering both water and organic materials to terrestrial planets like Earth.
The dust doesn’t carry enough water to generate the oceans, the scientists say, but they could be the source of the ice in permanently shadowed regions of the moon.
"It is a thrilling possibility that this influx of dust has acted as a continuous rainfall of little reaction vessels containing both the water and organics needed for the eventual origin of life on Earth and possibly Mars," said Hope Ishii, an associate researcher at the Hawaii Institute of Geophysics and Planetology at the University of Hawaii.
"Interplanetary dust, especially dust from primitive asteroids and comets, has long been known to carry organic carbon species that survive entering the Earth’s atmosphere, and we have now demonstrated that it also carries solar-wind-generated water," said Ishii, a co-author of the study, in a statement. "So we have shown for the first time that water and organics can be delivered together."
This mechanism of delivering both water and organics simultaneously would also work for exoplanets, worlds that orbit other stars, the researcher said. These raw ingredients of dust and hydrogen ions from their parent star would allow the process to happen in almost any planetary system.
How does it work?
Dust from comets, asteroids and leftover debris from the birth of the solar system is bombarded by the solar wind, predominately hydrogen ions. This ion bombardment knocks the atoms out of order in the silicate minerals and leaves behind oxygen that is more available to react with hydrogen, for example, to create water molecules.
The dust then rains down on Earth and other solar system bodies.
The study, conducted with scientists at the Lawrence Livermore National Laboratory, the Lawrence Berkeley National Laboratory and University of California at Berkeley, was published in the Proceedings of the National Academy of Sciences.
