When have the planets of our solar system formed? The discovery of tiny meteorites can challenge the chronology
A small meteorite rewrites what scientists thought of knowing about the origins of our solar system.
New evidence found in the chips of a meteorite known under the name of North West Africa 12264 – a piece of space rock of 50 grams (1.8 ounces) which have formed in the external solar system – suggests that rocky planets such as the earth and the icing bodies distant can be formed at the same time. This calls into question the long-standing belief that the planets closer to the sun have formed before those of the external solar system, those which are beyond the asteroid belt between Mars and Jupiter.
The planets are formed in the rotary discs of gas and dust that surrounds young stars, where particles collide and remain together by a process called accretion. While the development of rocky planets warms up, they start to differentiate themselves, forming distinct internal layers called nucleus, coat and crust.
Scientists have thought that the interior rock planets of our solar system – Mercury, Venus, Terre and Mars – first formed (about 4.566 billion years ago), while gas giants and frozen bodies in the external solar system gathered a little later (4.563 billion years), due to colder temperatures at a greater distance from the sun. It was also believed that rocky planets are more slowly formed because their water and ice content would have delayed internal heating and the development of nucleus.
The analysis of the composition of the meteorite (which was bought from a dealer in Morocco in 2018) revealed a report of chrome and oxygen which indicates that it came from the external part of the solar system. Using precise isotopic dating methods, the researchers found that the rock formed 4.564 billion years ago – only two to three million years after the first solid materials in the solar system.
In relation: How many meteorites hit the earth every year?
Until now, such early training has been limited to organisms of the inner solar system, according to a statement announcing the new study.
Evidence that the rocky planets beyond Jupiter have formed so quickly, and at the same time, because the interior planets could transform our understanding of the way in which planets take shape – not only in our solar system, but in the planetary systems of the universe, the researchers said.
Their results were published on July 4 in the journal Communications Earth & Environment.
This article was initially published on Space.com.
