Our solar system is quite special

Popular hypothetical models attempt to explain the formation of the solar system that the solar system is nothing special in every respect. But a new study by Northwestern University astronauts, using the latest data from 300 exoplanets with orbits around other stars, changed that view.

Our solar system is actually quite special. The study explains that if the initial condition is only slightly different, many unpleasant things may have happened, such as the planet being thrown into the sun or thrown into deep space.

With large-scale computer simulations, Northwestern University researchers are the first to set up a model to simulate the formation of the solar system from the first to the last stage, starting with the form of gas disk The rest after the central star forms and ends is the perfect planetary stage. Due to computer limitations, previous models only see a summary of the process.

Researchers have done more than 100 simulations , the results show that the origin of the average planetary system is dramatic and the activity is intense, but the information about our solar system requires things. Accurate facts.

New research is published in Science.

Before the discovery of the first planets outside the solar system in the early 1990s, 9 planets (now only 8) of the solar system are known only to us. The model of planet formation has many limitations, astronauts have no reason to think that the solar system is very special.

Frederic A. Rasio - theoretical physicist expert and professor of physics and astronomy at Weiberg University of Science and Arts - said: 'We know that other planetary systems are not the same. our sun '. Frederic A. Rasio is also the author of a research paper in Science . 'The orbital shape of the outer planets is elongated, not round. They are not in the positions we anticipate. Many large planets similar to Jupiter, also known as 'hot Jupiter' are located near the stars they orbit around during the day. Clearly we need to thoroughly explain the planet formation as well as the great diversity of the planets we observe today. '

Photos of planets.Our solar system turns out to be quite special.(Photo: NASA / Jet engine laboratory)

With extrasolar data collected during the past 15 years, Rasio and his colleagues are studying to understand the process of planet formation with a wider meaning than before. Setting up a model of a planetary system - a diverse physical phenomenon involving gas, gravity and matter particles at various levels - is a great challenge. Work requires a powerful computer. Researchers must also determine wisely which information is important, which information does not speed up calculations. They decided to monitor the development of the planet, the gravitational interaction between planets, and the planetary system in the process of expanding into space. They decided not to follow the gas disk fluid dynamics in detail but only at a general level.As a result, they were able to perform simulations that connected the entire process of planetary system formation.

Simulation shows that the origin of an average planetary system is extremely variable. The gas disk that forms the planets also pushes them mercilessly to the central star where they gather together or are engulfed. For planets that are forming, there is a competition for gas, a chaotic process that creates a variety of planetary masses.

As the planets approach each other, they often have a dynamic resonance that causes the orbits of all the related planets to be significantly extended. Such gravitational force interactions often cause collisions to knock the planet somewhere in the system. Sometimes a planet is thrown out of the system, flying into deep space. Although the gas disk always 'tried' to destroy its descendants, it eventually destroyed and faded away. Then a young planetary system is formed.

Rasio said: 'The chaos calendar may have reserved a place for the peaceful solar system, our simulation also shows exactly that. The conditions must be suitable to create the solar system '.

For example, if the gas disk is too large and the process of forming a chaotic planet will create 'hot Jupiter' and many orbits of a non-circular shape. If the gas disk is too small, it will not be able to form a larger planet than Neptune - a giant ice planet with very small amounts of gas.

'We now have a deeper understanding of the process of planet formation and can explain the properties of the strange extraterrestrial we observed. We also know that the solar system is very special. To some extent we understand what makes it so special. '

'The solar system must be formed in suitable conditions to become a quiet place as we see it. Most other planetary systems do not have these special characteristics when they act so they are very different from our solar system. '

In addition to Rasio, other authors of the Science article are Edward W. Thommes - Guelp University assistant professor in Ontario, a former postdoctoral researcher at Northwestern University, and Soko Matsumura - postdoctoral researcher. Doctor of Northwestern University.

Computer simulations were performed on supercomputers controlled by Northwestern University's Theoretical Physics Group. The research was funded in part by the National Science Foundation. Rasio's team on extraterrestrial research is also funded by the Astronomical Committee, the National Science Foundation.

Refer:
Gas Disks to Gas Giants: Simulating the Birth of Planetary Systems.Science, August 8, 2008