Comments:
This image is a double exposure of the asteroid. This is achieved by taking two timelapse exposures separated by a short interval and superimposing the two images together. The resulting image shows two short streaks caused by the relative movement of the asteroid and the Earth.

1997 AE12 is a 5km piece of rock which orbits the sun in an irregular orbit. Because its orbit occupies a different plane to the Earth's orbit, there is little or no chance of the two bodies colliding.