[Izzy Dunne]

Since most (all?) of the junk is metallic, how about an orbiting supermagnet?

[Fitzcarraldo]

Since most (all?) of the junk is metallic, how about an orbiting supermagnet?

Depends on the composition of the material and the strength of the magnet ;^).

http://en.wikipedia.org/wiki/Space_junk

http://www.orbitaldebris.jsc.nasa.gov/

(before the Chinese event)

[Fitzcarraldo]

Since most (all?) of the junk is metallic, how about an orbiting supermagnet?

Here you go:

"...If magnetically susceptible, the debris could fall in a few decades due to the drag of the Earth's magnetic field..."

[Right Wing Assault]

Since most (all?) of the junk is metallic, how about an orbiting supermagnet?

My guess is a lot of that metal is aluminum and magnesium, which are minimally affected by magnets.

[dr_lew]

My idea is a huge ball of styrofoam that would sweep up objects then reenter after orbital decay, which would be rapid for a large low density object.

Not sure how that would work out!

Problems:

Low encounter rate.

Engineering a "capture density" for the styrofoam.

Getting it up there.