The Oort cloud is the most distant region of our solar system. Unlike the orbits of the planets and the Kuiper Belt, which are mainly in the same flat disk around the Sun, the Oort cloud is believed to be a giant spherical shell that surrounds the rest of the solar system; like a great bubble made of icy chunks of space debris the size of mountains or even larger. This striking trans-Neptunian object can contain billions, or even billions, of objects.
Now, a team of astronomers from the University of Leiden (Netherlands) has managed to calculate the first 100 million years of the history of the Oort cloud. Its genesis. Until now, only parts of the history of the Oort cloud had been studied. Brushstrokes separately. This is the first time that it has been possible to estimate chronologically this region whose closest objects are even further from the Sun than the very confines of the Kuiper belt.
Astronomers have announced that they will soon publish the full simulation of these first 100 million years and their consequences in the journal Astronomy & Astrophysics.
When was the Oort cloud discovered?
This huge container of comet-like objects was discovered in 1950 by the prestigious Dutch astronomer Jan Hendrik Oort in order to explain why there are still new comets with elongated orbits in our solar system. He named, therefore, the comet torus that is found around the solar system (although he also made other interesting discoveries in astronomy , such as testing the rotational motion of the Milky Way through exhaustive observation and analysis of the motion of stars or calculating the distance between the center of the Milky Way and the Sun, among other things).
Where are you from?
The clarification of the origin of the Oort cloud has always been controversial for astronomers, since computer simulations have always yielded contradictory results, hence they concluded to study events separately. For this study, the researchers decided to try something different: to use these phenomena examined separately but connecting them together, using the final result of the first calculation to start the next one. And they saw that in this way, it was possible to create the complete genesis of the Oort cloud.
The result, after the new simulations, is that the Oort cloud was formed from the remains of the protoplanetary disk of gas and debris in our solar system, which appeared about 4.6 billion years ago. And comet-like objects come from two different places in the cosmos: the first, thrown by the giant planets; the second, of other stars; that is, the Oort cloud would have captured comets that initially would have belonged to other stars when the Sun had just risen.
The Oort Cloud arose from a cosmic conspiracy
“With our new calculations, we show that the Oort cloud arose out of a kind of cosmic conspiracy, in which nearby stars, planets, and the Milky Way played their part. Each of the individual processes alone would not be capable of explain the Oort cloud. You really need the correct interaction and choreography of all the processes together. And that, by the way, can be explained quite naturally from the environment of the first manifestation of the Sun. So, although the Oort cloud it is formed in a complicated way, it is probably not unique, “explains astronomer Simon Portegies Zwart.
Referencia: Oort cloud Ecology II: The chronology of the formation of the Oort cloud. Accepted for publication in Astronomy & Astrophysics. Free preprint: arxiv.org/abs/2105.12816 arXiv:2105.12816v1 [astro-ph.EP]
