Scientists at Leiden University in the Netherlands have built the first mathematical model for the formation of the Oort cloud.
The Oort cloud is a hypothetical spherical region of the solar system that is the source of long-period comets. Instrumentally, the existence of the Oort cloud has not been confirmed, but many indirect facts indicate its existence.
In order to study the object, the authors of the new work combined all the information on all individual events associated with the Oort cloud and built a model of its formation during the first 100 million years after the formation of the solar system about 4.6 billion years ago.
The model was made so that the final result of each previous event was taken as a starting point for the next one. Thus, different parts of the puzzle were able to connect with each other and display the entire evolution of the Oort cloud.
As a result, it turned out that the cloud is the remnant of a protoplanetary disk of gas and debris, from which the solar system arose about 4.6 billion years ago. Comets come from two sources: some originated around the sun, others came from outer star systems.
With the help of our calculations, we show that the Oort cloud appeared as if as a result of some kind of cosmic conspiracy. Its formation requires a variety of interactions and the correct choreography of each process. But it is logically explained by the history of the stars. So, although the Oort cloud is complex, it is most likely not unique.
Simon Portegis Zwart, first article author, astronomer, and modeling expert