Space junk

Hello my friends, Already think of the garbage that we have around our home mother (earth)?
Well, the garbage is huge, and our dear friends at NASA still continue to go to space as often as they like, leaving just a little more junk, in the thinking of them "fuck it," and their condition may still be Them to do these missions.

According to researchers, within 20 years will never be possible to carry out their missions due to the debris that exist around our planet, are about 170 million debris in our around 5,000 launches already made.
Now a question, why is it that when we search for earth does not appear the debris around it? Why hide them?