Those of you who have seen the excellent Alfonso Cuarón film Gravity know just how problematic space debris can be...
This space pollution has been growing since spaceflight became possible (the first artificial satellite - Sputnik - was launched in 1957 and the first manned spaceflight took place in 1961), and at some point we're going to have to do something to clean up the heavens. How can this be done? One way would be with what is called a 'laser broom' (great name, no?).
The idea would be to use a ground-based laser that is powerful enough to reach the debris in orbit and ablate enough material off the debris to take them off course and shorten their life in Earth's orbit (they burn up coming down in the atmosphere).
Anyway, back to Orbital Objects. It's a great interactive visualization of active satellites (in green), inactive satellites (gray), and tracked space debris (in red). Obviously, this doesn't include un-tracked debris.
The images in this article give you an idea of what it looks like, but it's best to go play with it and see for yourself. It's not the same when you fly around all these orbital objects and can see the circle of green satellites in that sea of red.
Just drag around by clicking your mouse somewhere and holding the button while you move. You can zoom in with the up and down keyboard arrow keys or with your mouse scroll wheel.
Here's the south pole:
Here's another different view that gives a good idea of the amount of stuff up there, but it's not as cool as the Orbital Objects website because it's not interactive.
Via Orbital Objects