Spark of life

Whenever I happened to watch some B (or C, or D) movie in which volcanic wrath formed the perfect background to uncanny, sinister events, I remember attributing the momentous bolts of lightning to rather OTT special effects. Eyjafjallajökull's spectacular fireworks, however, have reminded me that, in fact, lightning is a common phenomenon accompanying volcanic eruptions, so I decided to investigate: 'lightning bolts in the hot dust and gas plumes of exploding volcanoes may have seeded the ancient Earth with one of the essential ingredients for life', suggested the New Scientist.

What happens is that lightning splits carbon dioxide molecules, and the ensuing reaction between oxygen atoms and nitrogen forms nitric oxide.

Now, although fairly simple, nitric acid (NO), is something of a star molecule, and in 1992 was proclaimed 'Molecule of the Year' because of its regulating role in many cellular functions. The high point of its career, however, seems to have come soon after the Earth became stable enough for life to evolve.

Way before the Jurassic Park era, when the Earth was young - and terribly acned with carbuncular volcanoes - nitric acid, which was produced also by lightning, shielded primitive microorganisms from the toxic effects of ozone, of which there was plenty in the atmosphere. And so the primitive microorganisms survived and grew more sophisticated, and, well, here we are.

(More in Science Direct. Below, lightning illuminates the sky around Eyjafjallajökull)

Image source: the Telegraph