100 thousand light-years 十万光年 We look face-on direcdly at the Milky Way spiral.A hundred billion stars murually bound by gravity encircle the central region,some passing close in,some in wider orbits.Our own sun swings with the rest in dignified passage clockwise about the distant galactic center,once every three hundred million years.External galaxies akin to our own are scat. tered throughout space as far as we can see.They too rotate slowly as they drift. m▣P.C▣m十万光年