Solar superflares may have gotten life started on early Earth
by Graham Templeton
Life very often finds ways of exploiting destruction, from bacteria and fungi in a decaying body to plant life in the charred remains of a forest fire. Now, new research shows that this trend may have held true even back when the Earth had just formed into a cold, inhospitable globe. There was no life at that time, and yet it seems that it was a sudden, violent influx of energy that may have gotten it started.
The issue is basically heat. In its early life-cycle, the sun was only about 70% as active as it is today, and calculations show that this shouldn’t have provided the Earth with enough warmth to support life — and yet, everything we know about the development of early life says that it was warm enough, and that there was life at this time. What’s the explanation? Evidence about the atmospheric composition of the early Earth shows that the much-maligned greenhouse effect might deserve the credit. Still, that just pushes the question one notch further down the line. If the greenhouse effect is what warmed the Earth, what caused that greenhouse effect?
Classically, we’ve looked to compounds like CO2 and nitrogen gas (N2) to explain it, but we again have to ask a further question: what created those? Life can put in the work to create high-energy molecules. But this is a time before life existed, so we need some model for where those greenhouse gas molecules came from, how the atoms got pushed together into such large quantities of molecules that do not form spontaneously. In the past, scientists have looked at things like lightning strikes and meteor impacts to provide the catalyzing energy needed to create such things, but the volumes have never worked out, so they could explain the full heat discrepancy on Earth.
This new study looks at readings from Sun-like stars to determine the effects of the so-called “superflares” produced by such stars in their early development. What they found was that superflares going off in quick succession would have created shocks that compress the Earth’s magnetosphere, expanding the openings at the two poles, allowing in all kinds of particles that would otherwise be deflected by the Earth’s magnetic field. It’s these highly energetic particles that could have catalyzed the creation of relatively complex greenhouse gases, which in turn warmed the Earth enough for water to melt, and life to begin.
One researcher told ABC News that, “While the Sun was throwing a tantrum, paradoxically this was a good thing for life.” Abiogenesis, the creation of life from non-living parts, could be the result of a leak in the Earth’s radiation shielding.
The greenhouse effect may have been good for us originally, but it’s getting a bit out of hand at this point.
Pure greenhouse gasses like CO2 could arise this way, but such compounds will also be destroyed or disassembled for creation of even more complex molecules. Nitrogen gas, carbon dioxide, and methane can be reacted with energy input to create nitrous oxide and hydrogen cyanide, both essential to the proper functioning of life. The team’s calculations show that these superflares will destroy enough of these molecules as to make them even more clearly incapable of explaining the early greenhouse effect on their own.
These are the same solar superflares that could ever well fry astronauts en route to Mars. But the research team proposes that the superflares’ driving of the development of nitrous oxide is the only reason we’re even here at all.
Note: This article was originally published on ExtremeTech.com.
