Re: New asteroid discovered with a less than one AU orbit
A more detailed version of the LINEAR pr is online at: http://www.space.com/scienceastronomy/asteroid_inside_030214.html
The asteroid is estimated to be 1km across - much too large to have been a lost rocket or probe. It's likely to be the first of many such objects to be found - inner solar system asteroids are difficult to spot from Earth because you have to point your telescope dangerously close to the Sun to spot them; but small space units along the lines of Canada' NESS or ESA's Earthguard-1 would see them quite easily.