Comments:
This image is a triple exposure of the asteroid. This is achieved by taking three timelapse exposures separated by a short interval and superimposing the images together. The resulting image shows three dots, which are in fact the single object moving in relation to the Earth.

Cruithne is a companion of the Earth, it shares the same orbit. When viewed from the Earth, its orbit appears to be horseshoe shaped, but this is an effect of viewing an orbit from a rotating planet. It actually passes closer to the Earth than the Moon. This asteroid is about 5km wide.