Earth formed about 4.5 billion years ago and life in its most elemental form appeared about 500 million years later.
Multi cellular life was a reality 2,000 million years ago and most of the animal life arose 541 million years ago in what was called the Cambrian explosion.
The rest is history, or maybe not? It seems that no: meteorites recently studied with a international team of researchers, tell us that something very important happened in the solar system shortly after (in geological terms) the Cambrian explosion.
The fact is, we do not know what.
Meteorites have found pieces of rock that fall to Earth from outer space. They are formed from the remains of collisions between asteroids, moons and other planets.
There are many different types that reflect the composition of the bodies from which they were formed. By studying the different meteorites that have come to Earth scientists can better understand how the materials with which the solar system was formed evolved.
In the narration of the origin and history of planet Earth, meteorites appear to be of two stellar forms.
The first is shortly before and perhaps at the same time when life arises, with the late intense bombardment and, even knowing that they continued to fall, are not relevant again until 65 million years ago when a meteorite ended the existence of the great dinosaurs. Apart from this as the stories tell, nothing important happened in the Solar System, apart from a meteorite here and there and the evolution of the planets themselves.
However, a group of researchers, led by Phillipp Heck of the Field Museum of Natural History (Chicago, USA), has analyzed 43 micrometeorites coming to Earth about 470 million years ago and have found something surprising: more than half of the mineral grains found correspond to compositions completely unknown or extremely rare in the meteorites that arrive today to Earth. For example, 34% of the meteorites analyzed belong to what are known as primitive aconites: today only 0.45% of the meteorites that fall to Earth are of this type.
So, what does this all mean?
This implies that something extraordinary happened; it can be suspected that it was a gigantic collision in the Solar System, around this period; something so large that it changed the composition of the asteroids.
Such a discovery implies that we must review the history of the Solar System as we know it. From the beginning it is possible to include the collision of something with a rather large asteroid 466 million years ago that is the one that sends the pieces of rock that fall like meteorites in the planets and moons of the Inner Solar System.
It should also be kept in mind that meteorites arrived and collected over the last 300 years are not representative of those who came to Earth in earlier periods.
The study of the meteorites of that time throws a surprise that can change what we know about our planetary system. More than half of the meteorites found in this period correspond to compositions that are completely unknown or extremely rare today