This model of Kleopatra, a nickel-iron asteroid 217 km long, was reconstructed from observations by the radio telescope at Arecibo. It is not an artist's impression, this object is really in orbit. An article about it is here
I got the model from Dr. Ostro, and tweaked it a little for smoothness, but the data is public, so I've made it available for download. Many more asteroid models are linked from this NASA page
, search for "3-D" to find them.