One key ingredient for life thought to be delivered to Earth by meteorites may have been homemade after all.
The phosphorus that went into building the first DNA and RNA molecules is thought to have come from a mineral called schreibersite, which is typically found in meteorites (SN: 9/7/04). But a new analysis of minerals forged by a lightning strike hints that lightning may have produced enough schreibersite on early Earth to help kickstart life, researchers report online March 16 in Nature Communications.
That means “emergence of life is not necessarily connected to meteorite impacts,” says Sandra Piazolo, a geologist at the University of Leeds in England. A weather-fueled source for phosphorus could broaden the window of opportunity for life as we know it to arise on Earthlike planets throughout the universe.
Piazolo and colleagues analyzed a hunk of glassy material called fulgurite, which formed when lightning zapped the ground in Illinois in 2016 (SN: 2/14/07). By firing lasers, X-rays and electrons at the fulgurite and observing how those beams interacted with the material, the researchers were able to probe its composition. They discovered that the fulgurite was studded with tiny kernels of schreibersite, which collectively made up about 100 grams — or about 0.4 percent — of the lightning-made material.