#declare T=-1;
#while(T<100)
 #local P=2*pi*T*(1+1/300);
 sphere{ < (0.5+T/2)*cos(P), (0.5+T/2)*sin(P), 15+T*T/35 >, 0.28+T/100*6
         pigment{rgb <.6,.9,.2>}
         finish{specular 0.6 roughness .001}
         normal{granite .3 scale .3}
       }
 #declare T=T+1/21;
#end 

light_source{<0,5,-7>rgb 1}