Question: How do you build planets? How many have you built?

Stefan Lines answered on 17 Nov 2014:

To put it in context, the reason I build planets (using computers) is that we try to reproduce observable systems (like our own Solar System) based on the physics behind their formation. It gives us some indication as to whether we are right or wrong behind our theories.

To do so, I use a special computer codes (called N-body and Fluid codes) which simulate huge disks of rock and gas which we believe surround young stars, and from which planet are made. In a very simple way, these rocks collide with each other and grow into planets. The code calculates the gravitational forces between all the rocks, and the star(s) too, so that they move as they would in a real system. Then we use a collision model to calculate whether these rocks merge, bounce or explode on impact.

I’ve made hundreds of small planets in my work so far, but my recent research requires years of computing time to build them.