This image, taken by the Hubble Space Telescope, is filled with many astronomical objects. Background galaxies are scattered throughout the image, from large spirals to blurry ellipticals, and there are bright foreground stars much closer to home surrounded by diffraction spikes. In the center of the image, the faint shape of small galaxy UGC 7983 appears as a hazy cloud of light. UGC 7983 is located about 30 million light-years from Earth in the constellation Virgo and is a type of irregular dwarf galaxy thought to be similar to the oldest galaxies in the universe.
This image also hides an astronomical helper. A small asteroid just a few kilometers in diameter is visible in the upper left corner of this image. The asteroid trail can be seen as four bands of light separated by small gaps. These streaks of light represent four separate exposures combined to create this image; Small gaps between each observation required to change the filters inside the NASA/ESA Hubble Advanced Survey Camera (ACS).
The asteroid’s capture was a happy side-effect of a larger effort to observe all known galaxies near the Milky Way. When this project was first proposed, about 75% of all of the Milky Way’s galactic neighbors were imaged by Hubble. A team of astronomers suggested using the gaps between Hubble’s longer observations to image the remaining 25%. This project was an elegant and fruitful way to fill some gaps not only in the Hubble observational timeline, but also in our knowledge of nearby galaxies.