A MARTINEZ, HOST:
The idea that lightning can spark life has been around a while.
(SOUNDBITE OF FILM, "FRANKENSTEIN")
COLIN CLIVE: (As Henry Frankenstein) It's alive. It's alive. It's alive. It's alive. It's alive.
MARTINEZ: That from the movie "Frankenstein," you better know that one. Now, scientists have come up with a new idea of how lightning could help life get going. Billions of years ago, lightning strikes may have forged a key chemical ingredient. NPR's Nell Greenfieldboyce reports.
NELL GREENFIELDBOYCE, BYLINE: When lightning zaps the ground, it instantly melts whatever's there to create a fulgurite or lightning rock. These haven't been studied much. But about five years ago, lightning struck the backyard of a family that lived near Wheaton College in Illinois, so they called its geology department. Benjamin Hess was a student there. He's now at Yale University. He says this fossilized lightning looks like a gray tree root with parts branching off.
BENJAMIN HESS: And it's just entirely made of glass and has, like, burnt soil on the outside of it.
GREENFIELDBOYCE: Inside, he found something unexpected - a highly reactive mineral that contains the element phosphorus.
HESS: Which was very strange. I've never encountered a phosphide as a geologist before.
GREENFIELDBOYCE: As he started reading about it, he realized...
HESS: This could actually be a really important mechanism for phosphorus on early Earth.
GREENFIELDBOYCE: Because here's the deal - when life emerged over 3 billion years ago, it needed phosphorus. It's essential.
HESS: Like, phosphorus makes up the backbone of DNA, for example.
GREENFIELDBOYCE: The trouble is, the young Earth's phosphorus would have been locked up in rocks that don't dissolve easily in water. That's why scientists have long thought that early life got the phosphorus it needed from minerals delivered by meteorites. To see how much lightning might have contributed, Hess and a couple of colleagues did some calculations.
HESS: So there are a lot of things to consider, like what was the dominant rock type that was being struck on early Earth? What was the atmosphere like? How much lightning would come from that atmosphere?
GREENFIELDBOYCE: In the journal Nature Communications, they say that back when life got its start, lightning could have provided about as much or slightly more phosphorus than meteorites did. Hilairy Hartnett is an astrobiologist with Arizona State University. She says this is a pretty cool idea.
HILAIRY HARTNETT: It's really nice to be able to say there's more than one path to generating phosphorous that could be available to a planet that might be able to develop life.
GREENFIELDBOYCE: Because she and others are looking for all the ways that life could get what it needs on Earth or elsewhere. Nell Greenfieldboyce, NPR News.
(SOUNDBITE OF WESS MEETS WEST'S "A WELL DRILLER'S SON")
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