Researchers in Sweden have found a new class of meteorite. And according to LiveScience, that discovery — published in Earth and Planetary Science Letters — may be the missing link in the asteroid crash that sparked the diversification of life on Earth nearly 500 million years ago.
destruction and species diversification
The meteorite in question was found in a quarry located just west of Stockholm. Finding meteorites there isn’t all that surprising, given that more than 100 have been dug up in the past 20 years. But previous finds were all of the common L-chondrite variety, a class of meteorite that started raining down on Earth 470 million years ago when a small asteroid crashed into a much larger one made up of these L-chondrites. That crash, scientists say, caused a meteor shower that resulted in just the right amount of destruction to drive animals and plants to diversify and form new species. But the specifics of that crash have always been shrouded in mystery, because the composition of the first, smaller asteroid is unknown. That’s why the new meteorite discovery is so important: scientists think it’s a fragment of the "asteroid destroyer" that triggered an explosion of species diversification on Earth.
David Harper, a geologist at Durham University who did not participate in the study, told New Scientist that "the team may at last have identified the impactor responsible for the break-up of the parent body of the L-chondrite meteorites."
But that finding will need to be validated, because some scientists aren’t even sure it belongs to a new class of meteorite yet. Timothy Swindle, a meteorite expert at the University of Arizona, told LiveScience that he thinks scientists might still be able to link it to known classes of meteorite — despite the compositional differences that set it apart from previous finds. "I think it's entirely plausible [that it's a new kind of meteorite], and it's a great study, but that's not a guarantee they've got it right," Swindle said. "But if they didn't, it's because of new things we'll find out in future work, not because of their analysis."
scientists are calling it the "mysterious object"
The new meteorite hasn’t been named yet, but it might end up being called "Österplana," after a nearby church. In the meantime, however, researchers are choosing to call it the "mysterious object" — and given the questions that continue to surround it, that interim name seems appropriate.
"One thing our study shows is that we maybe don't know as much as we think we know about the solar system," Birger Schmitz, lead author of the study, told LiveScience. "I think our new finding adds to the understanding that the meteorites that come down on Earth today may not be entirely representative of what is out there."