How to print output:

StdOut.printf("%d\n", planets.length);
StdOut.printf("%.2e\n", radius);
for (int i = 0; i < planets.length; i++) {
	StdOut.printf("%11.4e %11.4e %11.4e %11.4e %11.4e %12s\n",
   		planets[i].xxPos, planets[i].yyPos, planets[i].xxVel, planets[i].yyVel, planets[i].mass, planets[i].imgFileName);	
}