Week 2 the fourth reading journal

Planets Being Pulverized Near Giant Black Holes?

http://news.nationalgeographic.com/news/2011/11/111101-black-holes-planets-dust-collisions-galaxies-space-science

(The article was too difficult to understand...)
Summary
    Generally, super-massive black holes are in the center of big galaxies, and most of them are unclear with debris and fragments. Astronomers do not realize where such dust come from, and how the dust remains around the black holes for a long time. But a new theory mentions that newly born planets and asteroids are whirling, clash each other continually with the very high speed, and make dust around the huge black holes.
   People have thought that black holes have only fragments or dust around them so far, but the new theory says they have asteroids and planets which can orbit around the black holes, like the solar system. Meanwhile, stars around the black holes have also huge gravitation. Such planets which were forced to release from the host stars are pulled with each other by the gravitation. So, smashing occurs many times, and much dust is born, a researcher believes.
   The planets and asteroids around the black holes seem to be cruel demise, but the researcher says that the much dust can cut off much of the X-ray and the gamma ray, and the dust can help other stars or planets to stay in a safer and quieter circumstance. He believes it is much more diverse environment around the black holes.