Unknown alien rock found in Swedish quarry
A never-before-seen chunk of a̳l̳i̳e̳n̳ rock has been unearthed in a limestone quarry in Sweden, where it has been buried deeply for some 470 million years, scientists said Tuesday.
The cookie-sized remains are unlike any other meteorite found on Earth to date and could shed light on the history and formation of our Solar System, they reported in the journal Nature Communications.
Dubbed West 65, it is believed to be a sliver of a potato-shaped rock about 20 to 30 kilometers wide that collided with another much larger body, sprinkling our teenage planet with debris.
Previously, remnants of only one of the two rocks had been found, in the form of meteorites called chondrites.
But now scientists believe they have unearthed a piece of the second space orb, adding to the theory of a major collision between two galactic travelers.
The breakup of the largest chondrite body, about 100-150 km in diameter, is thought to have produced a large clump of rocky debris in the asteroid belt between Mars and Jupiter.
The resulting flow of e̳x̳t̳r̳a̳t̳e̳r̳r̳e̳s̳t̳r̳i̳a̳l̳ material, some of which rained down on Earth, coincided with a massive expansion of invertebrate ocean life at a time when our planet\’s landmass was largely merged into a supercontinent called Gondwana.
“The only meteorite we\’ve found now is of a type that we don\’t know about in the world today,” study co-author Birger Schmitz of Lund University in Sweden told AFP.
Along with about 100 pieces of chondrite discovered to date, the new a̳l̳i̳e̳n̳ fragment sank to the bottom of an ocean that covers parts of what is now a limestone quarry in southern Sweden.
\’Extinct\’ space rock?
“The object contains very high concentrations (compared to Earth materials) of elements such as iridium, which is very rare on Earth,” Schmitz explained by email.
“The meteorite also contains high concentrations of rare isotopes of the element Neon” – and in proportions different from those of chondrites.
The team measured telltale signs of cosmic radiation on the meteorite to determine how long it flew in space before crashing into Earth.
“Our meteorite fell 470 million years ago,” Schmitz said — about the same time period as the chondrite fragments.
The mysterious piece “may be a fragment of the impactor that broke the parental (chondritic) body,” the study concluded.
The e̳x̳t̳r̳a̳t̳e̳r̳r̳e̳s̳t̳r̳i̳a̳l̳ lander may be the first documented example of an “extinct meteorite” – so named because its parent body was totally consumed by space collisions, meaning no fragments can fall to Earth today.
Chondrites still fall on our planet from time to time.
The findings mean that today\’s meteorites – on which scientists base many of their assumptions about the formation of our Solar System – are not fully representative of what is, and once was, out there.
“Apparently, there is potential to reconstruct important aspects of the solar system\’s history by looking at Earth\’s sediments in addition to looking at the skies,” the study authors wrote.