uranologist have found evidence for a unexampled character of meteorite on Earth , one which may explain how many other meteorite made their way to the aerofoil .
More than a third of all the 50,000 or so have a go at it meteorites are calledL chondrites , fragments from a large “ parent ” asteroid about 150 kilometre ( 93 miles ) wide , which was hit by a smaller asteroid a tenth the size 470 million years ago . We have loads of meteorite from the larger asteroid but , until now , none from the smaller impactor .
Thanks to researchers led by Birger Schmitz from Lund University in Sweden , we have an perceptiveness into the other player in this asteroid collision . They establish a fossil meteorite in the Thorsberg limestone pit in southern Sweden that is unlike any other , but with the same age as L chondrite meteorite , suggesting it was from the smaller impactor . The findings are published inNature Communications .
“ It is unique , ” Schmitz secern IFLScience . “ What make it so particular is that it has a composition that does n’t resemble any meteorite that we be intimate of today . ”
He added : “ We trust that it is a piece of the impact [ 470 million years ago ] , the smaller object that polish off the bigger L chondrite parent body . ”
Shown is the dodo meteorite in the center . Birger Schmitz
The small fogey meteorite , dubbed ? st 65 , measures just 8 cm ( 3 inches ) across . Its age was calculated by measuring the meteorite ’s cosmic ray exposure , and its unique composition of chromium and O isotope make it different from any live meteorite .
Every meteorite on Earth come from a parent asteroid , and each has a discrete oxygen and chromium isotope composition . Of the 50,000 meteorites found so far , each can be traced back to 160 parent eubstance . But this fresh meteorite does not match any pre - existent category .
“ Our finding kick in a hint that meteorites that downslope on Earth today may not be representative of what has been diminish on our satellite through the ages , ” Schmitz distinguish IFLScience .
Unfortunately , the asteroid that this new meteorite fare from is probably now nonextant , having been destruct in the collision , which was one of the most violent events in the Solar System in the last 3 billion eld . So it ’s improbable that any other pieces of it will precipitate to Earth , and finding more fossilized fragments will be difficult ; this particular one took 25 years to find .
Nonetheless , Schmitz say they are now change by reversal their attention to much smaller debris , micrometeorites , in an endeavour to memorise more about ancient asteroids like this from the asteroid belt .
present is the prey where the fossil meteorite was found . Birger Schmitz
One secret remain , though . Namely , what happened to the parent asteroid after the hit ? Astronomers have found a duo of candidates that may be the corpse , including the Flora family line of asteroid in the asteroid belt . But even this latest discovery may not aid us answer that question .
Still , it ’s exciting that we now know more about how many of our meteorites made their fashion to Earth . And , append Schmitz , “ there ’s still a lot to be understood about the asteroid swath . ”
