Scientists at the University of California Lawrence Livermore National Laboratory have uncovered the mystery of the time of the solar system’s appearance, which happened approximately 4.5 billion years ago. It turned out that the formation of the Sun and protoplanets took only 200 thousand years. This is reported in an article published in the journal Science.
The solar system arose as a result of the gravitational collapse of a large cloud of dust, the substance of which consists of most of the celestial bodies in it, including the Sun and planets. Astronomers have previously observed other planetary systems and concluded that it takes 1-2 million years for a cloud to collapse and transform into a parent star and planets. However, a new study revealed that the solar system emerged very quickly.
Researchers have determined the content of molybdenum isotopes in calcium and aluminum-rich inclusions (CAIs), which are considered the oldest dated structural elements of chondrite meteorites. Most CAIs formed 4.567 billion years ago, between 40 and 200 thousand years ago, in a high-temperature environment near the young Sun. They were then transferred to the region where the meteorites formed. Since the CAI formation time is shorter than the estimated solar system formation time, it was not clear what phase the inclusions occurred in.
It turned out that in CAI there are variations in the isotopic composition of molybdenum, arising from the inhomogeneous distribution of matter in the protoplanetary disk. This means that the formation of the outer and inner regions of the solar system occurred during the period of inclusions, when the sun was transforming from a protostar into a main sequence star. Thus, all the matter of the cloud, from which a large part of the solar system arose, was attracted to the Sun for 200 thousand years.