This Hubble Space Telescope image of the barred spiral galaxy UGC 12158 looks like someone took a white marking pen to it. In reality it is a combination of time exposures of a foreground asteroid moving through Hubble's field-of-view, photobombing the observation of the galaxy. Several exposures of the galaxy were taken, what is evidence in the dashed pattern. The asteroid appears as a curved trail due to parallax: because Hubble is not stationary, but orbiting Earth, and this gives the illusion that the faint asteroid is swimming along a curved trajectory. The uncharted asteroid is in inside the asteroid belt in our solar system, and hence is 10 trillion times closer to Hubble than the background galaxy. Rather than a nuisance, this type of data are useful to astronomers for doing a census of the asteroid population in our solar system.