This image was captured by the NASA / ESA Hubble Space Telescope and also displays a number of astronomical objects. Background galaxies which range from fixed spirals to fuzzy ellipticals are dispersed throughout the picture, and bright foreground stars much nearer to home are present, surrounded by diffraction spikes. The vague form of the small galaxy UGC 7983 shows up in the middle of the picture as a hazy light cloud. UGC 7983 is approximately thirty million light years from Earth in the constellation Virgo, and it is a dwarf abnormal galaxy – a type believed to be much like the very first galaxies in the universe.
An astronomical interloper is concealed in this picture. A small asteroid having a diameter of just a couple of kilometers are observed streaking across top of the left side of this picture. The asteroid trail can be seen as four light streaks separated by little gaps. These light streaks represent the 4 distinct exposures which were put together to produce this picture. the little spaces in between each observation were needed to change the filters of Hubble’s Advanced Camera for Surveys.
The capture of an asteroid was a good side effect of a bigger effort to look at each known galaxy close to the Milky Way. When this particular project was initially proposed, Hubble had imaged more or less 75% of all of the near galactic neighbors of the Milky Way. A number of astronomers suggested making use of the spaces between more Hubble observations to take photos of the other 25%. The task was an elegantly effective way to fill in certain gaps in Hubble’s monitoring schedule, along with our understanding of nearby galaxies.
