By outdoor-nature-child.com On October 17, a significant question in the field of astronomy was addressed: where do meteorites, often dubbed “guests from outer space,” originate from? This inquiry has intrigued many and has motivated ongoing research among astronomers.
Recent studies published in the prestigious journal *Nature* have unveiled key insights into the origins of meteorites arriving on Earth. The findings suggest that the most common types of meteorites might stem from the fragmentation of just a few asteroids, some of which have experienced catastrophic disintegration relatively recently. Notably, the “Queen” asteroid family appears to be a major source of these meteorites.
According to the research, approximately 80% of the meteorites that impact Earth belong to a category known as ordinary chondrites. This category includes meteorites that were produced during a period of intense collisions about 460 million years ago, events believed to have triggered an ice age on Earth. Earlier studies indicated that around 70% of meteorites on Earth are composed of H-type and L-type chondrites. Moreover, argon-argon dating of L-type chondrites on Earth revealed that these samples likely originated from a catastrophic breakup of an asteroid, which was struck by a supersonic impact around 470 million years ago.
In the first paper, M. Marsset, the lead and corresponding author from the European Southern Observatory in Chile, collaborated with colleagues to analyze spectral data from asteroids located in the main asteroid belt between Mars and Jupiter. They discovered that a specific group of asteroids known as the “Queen” family shares a striking similarity in composition with L-type chondrites found on Earth. Through computer modeling, the researchers theorize that a collision roughly 450 million years ago caused an L-type chondrite asteroid to fragment, creating the “Queen” family and releasing a substantial amount of debris that potentially led to meteorite influx.
The second paper, authored by M. Brož and collaborators from Charles University in the Czech Republic, examined how current influxes of H-type and L-type chondrites might result from three relatively recent disintegration events occurring approximately 5.8 million, 7.6 million, and 40 million years ago, marking the destruction of several asteroids over 30 kilometers in diameter.
The researchers propose that impacts from relatively younger asteroid families, “Karin” and “Themis,” combined with a second impact event from the older “Queen” family around 40 million years ago, could explain the origins of most meteorites currently falling to Earth.
A parallel article published in *Nature* by fellow experts provided insights into these astronomical discoveries, helping us better understand the origins of the most commonly encountered meteorites and how these impacts may have shaped Earth’s history.