Read more: Found hereWhere do meteorites of different type come from? In a review paper in the journal Meteoritics ⁘ Planetary Science, published online this week, astronomers trace the impact orbit of observed meteorite falls to several previously unidentified source regions in the asteroid belt.
"This has been a decade-long detective story, with each recorded meteorite fall providing a new clue," said meteor astronomer and lead author Peter Jenniskens of the SETI Institute and NASA Ames Research Center. "We now have the first outlines of a geologic map of the asteroid belt."
Many more fireballs were tracked by doorbell and dashcam video cameras from citizen scientists around the globe and by other dedicated networks.
"Altogether, this quest has yielded 75 laboratory-classified meteorites with an impact orbit tracked by video and photographic cameras," said Jenniskens. "That proves to be enough to start seeing some patterns in the direction from which the meteorites approach Earth."
Most meteorites originate from the asteroid belt, a region between Mars and Jupiter where over a million asteroids larger than 1 kilometer circle the Sun. Those rocks originate from a small number of larger asteroids that broke in collisions, the debris fields of which litter the region. Even today, asteroids collide to create debris fields within these asteroid families, called clusters.
"We now see that 12 of the iron-rich ordinary chondrite meteorites (H chondrites) originated from a debris field called "Koronis," which is located low in the pristine main belt," said Jenniskens. "These meteorites arrived from low-inclined orbits with orbital periods consistent with this debris field."
