For centuries now, scientists have been toying with the idea that the origins of life may owe a great deal to space borne debris. And with ongoing research in the past few years, the link between Earth and Mars have become increasingly convincing. And a new bit of research out of the University of Hawaii has provided yet another piece of the puzzle by suggesting solar wind plays a major role.
Solar wind – the stream of charged particles consisting mostly of naked protons called H+ ions – permeate our Solar System because they are periodically ejected from the sun. The University paper shows that in an airless environment, typical space rocks will react with impacting protons to create tiny vesicles of water, thus allowing water and organic molecules to travel through space in tandem.
Interestingly, the paper comes soon after NASA released evidence that Mars once sported a fair amount of water in the past, and that this water is sometimes found in unexpected places. The finding that water can be generated within dry space rocks, coupled with the fact that space rocks are known to deliver organic compounds to the surface of the Earth, is yet another indication that Earth and Mars might be linked.
Other recent papers have suggested that life’s important molecules arrived intact from Mars – a primitive version of RNA is one major proposed molecular stow-away – but these researchers claim only that “complex organic molecules” came from somewhere else in space. Complex organic compounds and liquid water, in conjunction, could theoretically provide the potential for non-living material to come alive.
One important aspect of this idea is that it focuses on small particles of material, rather than comets. Prior research has looked to such large bodies as the carriers of life and the drivers of the chemistry that created it, due to their energetic impacts. It’s been suggested that the earliest living things were cobbled together from high-energy molecules that couldn’t exist unless their synthesis was driven by massive astronomical impacts.
This more passive, dust-based explanation seems to fit well with the known history of the Earth, which predicts there was a high level of dust flux in the period before life began to flourish. In addition, the theory could help explain how in the predominantly shadowy areas of the Moon – another airless silicate body – unexpectedly high levels of water have been detected.
NASA has plans to launch RESOLVE (Regolith and Environment Science and Oxygen & Lunar Volatile Extraction) in 2018 to collect and analyze ice samples and use them to look back into just that sort of astronomical history. Large quantities of water are thought to have arrived on the Moon via impacting comets, but this research suggests that at least some of it could have been created on the Moon itself.
All of this is of extreme importance to discovering how life began on Earth, mainly because scientists are still unsure of what makes the process complete. For instance, evolutionary theory can adequately explain how a bacterium becomes a protist that becomes an animal, but it cannot explain how a pile of non-living molecules ever became a living cell.
Evidence seems to be mounting that, whether it was seeded with dust or fused into existence by huge asteroid impacts, life on Earth needed a kickstart in its earliest days. Interestingly, Earth’s atmosphere and the abundance of messy lifeforms on its surface could mean that Earth is the single worst place to search for such evidence.
The Moon or Mars, by contrast, are perfect environments for preserving evidence of the past given their dry and airless nature. And with ongoing research into both planets and our scientific knowledge of them expanding apace, whatever role they may have played in kickstarting life on Earth may finally be learned. This could come in handy if ever we need to do a little kickstarting of our own…