Based on recent research conducted by geologist Birger Schmitz from Lund University, the majority of meteorites that have fallen to Earth came from a mysterious and unknown location in our Solar System’s asteroid belt. The asteroid belt contains millions of pieces of space rocks that orbit between Mars and Jupiter. While the majority of these space rocks are somewhat small (between the size of a boulder to a few thousand feet), some are a lot bigger.
Meteorites are smaller pieces that have broken off from much larger objects. The initial hypothesis was that these meteorites came from a major event that involved massive asteroids breaking apart in space. The problem with that theory is that according to Professor Schmitz, the meteorites that have fallen to Earth over the past 500 million years don’t coincide with any known collision event.
Schmitz has traveled the world looking for meteorites that date back millions and even billions of years. So far, he has gathered 10,000 kilograms of space rocks that have fallen to Earth in the last 500 million years. The samples were then put in hydrochloric acid so that the only thing left was a small amount of residue so that the extraterrestrial chrome-spinel grains could be analyzed.
While the purpose of his project was to find out the origins of these meteorites, the research has resulted with more questions than answers. It has been long believed that different meteorites originated from different parent bodies in the asteroid belt; however, Schmitz’s research seems to point to them all coming from one specific body that has been sending them our way for a steady 500 million years. There are still so many questions left unanswered though, such as what and where the parent body is, and how the meteorites ended up falling to Earth.
The research will hopefully help experts in regards to finding and studying asteroids that may one day threaten Earth. In an interview with Inverse, Schmitz said, “Meteorites tell us something about what type of objects threaten us in the future,” adding, “What type of objects do we have to be particularly aware of.”
Additionally, the data may help researchers learn more about the origins of our Solar System in addition to how our planets formed and evolved. Nicholas Castle from the Planetary Science Institute (but was not involved with the study), told Inverse, “Most meteorites date back towards the very early days of the Solar System,” adding, “So that's sort of our first clues for how did we go from big gas clouds to solid material.”
The study was published in the journal Proceedings of the National Academy of Sciences where it can be read in full.