Where the asteroids are. I did not know that the inner edge of the Belt is so close to Mars. This chart also shows diffuse extensions of the main Belt toward both Trojan clusters, and toward Anti-Jupiter: perhaps these are companions of Jupiter that have not yet been identified as such, or perhaps they are a fluke of the moment.
2004: Alas, the chart evidently is not updated.
2006: Yes it is!
The “diffuse extensions” are the Hilda group, in 2:3 resonance with Jupiter.