Accrete is a physical simulation of solar system planet formation. This simulation works by modelling a dust cloud around a Sun-like star, injecting a series of masses which collect dust, and form planets by accretion.

This project is to convert the original C project, found at https://sourceforge.net/projects/accrete/, to a pure javascript implementation. A line by line translation of the original code has been done in javascript, however many improvements can still be made. A emscripten compilation of the project is also possible as demonstrated in the emscripten/ directory.

Included in this distribution are the following libraries (BSD liscences can be found in sprintf.js and mtrng.js):

• sprintf.js by alexei, see https://github.com/alexei/sprintf.js
• mersenne-twister.js by Sean McCullough, see https://gist.github.com/banksean/300494

Accrete is a physical simulation of solar system planet formation, originally published to Usenet-- probably comp.sources.unix-- in 1991 by Joe Nowakowski. This software is in the public domain.

This simulation works by modelling a dust cloud around a Sun-like star, injecting a series of masses which collect dust, and form planets. The simulation then determines what the planetary environments will be like in terms of temperature, atmospheric composition, and other factors. The system description is saved to a file named "New.System".

The following output will give a good idea of the end results:

Planet #4:
   Distance from primary star (in A.U.): 1.038
   Eccentricity of orbit:	         0.004
   Mass (in Earth masses):   	         0.383
   Equatorial radius (in Km):         4675.0
   Density (in g/cc):  		         5.344
   Escape Velocity (in km/sec):          8.08
   Smallest molecular weight retained:	12.16   (CH4)
   Surface acceleration (in cm/sec2):  698.22
   Surface Gravity (in Earth gees):	 0.71
   Boiling point of water (celcius):    53.6
   Surface Pressure (in atmospheres):    0.146
   Surface temperature (Celcius):        8.39
   Hydrosphere percentage:              50.46
   Cloud cover percentage:              22.87
   Ice cover percentage:                 3.61
   Axial tilt (in degrees):     23
   Planetary albedo: 		0.177
   Length of year (in years):   1.06
   Length of day (in hours):   18.14

...but I'll include a directory of a few sample runs at some point. Enjoy.

			-Chuck Swiger <[email protected]>

PS: I've updated this program to use the Mersenne Twister RNG algorithm by Takuji Nishimura and Makoto Matsumoto in favor of the old random()/srandom(). Please see mtrng.c for license (BSD-style) and details.