final week the Earth was visited by an asteroid,and astronomers caught it on radar. Good thing it wasn't speeding.
The rock is called 2003 SD220, and it's what's called an Aten: an asteroid with an elliptical orbit that generally keeps it closer to the Sun than Earth, or but elongated enough that it crosses Earth's orbit. For this reason it's also a Potentially Hazardous Asteroid,one that is sizable enough and gets close enough to us that some time in the future there's a risk of an impact.
Source: blastr.com