Have you ever gazed up at the night sky and wondered where meteorites come from? A groundbreaking study published in the journal *Meteoritics & Planetary Science* reveals exciting new insights into the origins of meteorites, mapping out various source regions in the asteroid belt.

“This research has been a decade-long detective journey, with each meteorite fall providing valuable clues,” explains meteor astronomer and lead author Peter Jenniskens from the SETI Institute and NASA Ames Research Center. The findings represent the first outlines of a geologic map of the asteroid belt, changing our understanding of where these celestial rocks originate.

The odyssey began ten years ago when Jenniskens partnered with astronomer Hadrien Devillepoix from Curtin University and a collaborative team in Australia to establish a network of all-sky cameras across California and Nevada. These advanced systems expertly capture and track the brilliant displays of meteorites as they enter Earth’s atmosphere. Over the years, contributions from various institutions and citizen scientists enhanced this initiative.

“Concurrent efforts resulted in the development of the Global Fireball Observatory,” notes Devillepoix. “Together, we’ve successfully tracked 17 meteorite falls.” Many additional fireballs have been captured thanks to home security systems and dashcam videos, painting a clearer picture of meteorite trajectories.

The research has yielded a total of 75 lab-classified meteorites, each tied to their entry orbits through video and photographic data. “This wealth of information allows us to discern directional patterns of approaching meteorites,” Jenniskens adds.

Most meteorites hail from the asteroid belt—a vast region between Mars and Jupiter filled with over a million asteroids larger than one kilometer. These rocks are derived from a handful of larger asteroids that have been shattered in violent collisions. Presently, collisions are still occurring, creating new debris fields within distinct asteroid clusters.

The study identifies connections between meteorites and their source regions, some of which include major asteroids like Ceres, Vesta, and Hygiea. Remarkably, the research determined that 12 iron-rich ordinary chondrite meteorites (H chondrites) came from the Koronis debris field, a region located low in the pristine asteroid belt. These meteorites descended into the Earth from orbits closely aligned with this cluster.

Astronomers even calculate how long ago these rocks were excavated from their parent bodies by assessing the levels of radioactive elements they accumulate from cosmic rays. This measurement reveals that certain meteorites originated from specific clusters—three from the Karin cluster (5.8 million years old) and two from the Koronis2 cluster (10-15 million years old). Another meteorite has an estimated age of approximately 83 million years, linking it to the Koronis3 cluster.

In addition to H chondrites, the researchers discovered that low iron (L chondrite) and very low iron (LL chondrite) meteorites primarily emerge from the inner asteroid belt, building upon existing theories about their origins. “Our findings suggest that L chondrites stem from the Hertha asteroid family, which is located above the Massalia family,” Jenniskens elaborates.

Understanding the origins and trajectories of meteorites not only fascinates astronomers but is also crucial for planetary defense against Near-Earth Asteroids (NEAs). Just like meteorite orbits provide insights into their sources, NEA trajectories may reveal potential origins in the asteroid belt.

“While NEAs may not follow identical paths as meteorites, they originate from similar families,” says Jenniskens. The researchers stress that while great strides have been made in mapping these relationships, much work still lies ahead, akin to the early cartographers outlining uncharted territories.

What’s the future hold for this exciting research? As new astronomical facilities come online, scientists anticipate more direct observations of small asteroids interacting with meteorites before they impact Earth. Jenniskens famously guided the recovery of the first small asteroid collision, asteroid 2008 TC3, in 2008. The advancing technology promises a revolutionary increase in our understanding of meteorological phenomena in the coming years.

Stay tuned as this captivating journey unfolds. The universe still harbors countless secrets waiting to be uncovered!