Royal Astronomical Society | 2017 Feb 27
Planets are thought to form in the disks of dust and gas found around young stars. But astronomers have struggled to assemble a complete theory of their origin that explains how the initial dust develops into planetary systems. A French-UK-Australian team now think they have the answer, with their simulations showing the formation of 'dust traps' where pebble-sized fragments collect and stick together, to grow into the building blocks of planets. ...
Our Solar system, and other planetary systems, began life with disks of gas and dust grains around a young star. The processes that convert these tiny grains, each a few millionths of a metre (a micron) across, into aggregates a few centimetres in size, and the mechanism for making kilometre-sized 'planetesimals' into planetary cores, are both well understood.
The intermediate stage, taking pebbles and joining them together into objects the size of asteroids, is less clear, but with more than 3,500 planets already found around other stars, the whole process must be ubiquitous. ...
Spontaneous ‘dust traps’ – the missing link in how planets form
Swinburne University of Technology | 2017 Feb 28
Self-Induced Dust Traps: Overcoming Planet Formation Barriers - J.-F. Gonzalez, G. Laibe, S.T. Maddison