Left:
A NASA Hubble Space Telescope image of a randomly selected area of sky taken to search for faint red stars that might constitute dark matter in our Milky Way Galaxy. The 38 simulated stars (diamond-shaped symbols), based on theoretical calculations, illustrate what scientists would have seen if the dark matter were locked-up in faint red stars.

Right:
The unmodified HST image shows the region is actually so devoid of stars that far more distant background galaxies can easily be seen. This region was chosen to highlight stars in the galactic halo, where dark matter exists, and to avoid the contribution of faint stars in the plane of the galaxy.

Courtesy Space Telescope Science Institute (STScI)

Credit: J. Bahcall, Institute for Advance Study, Princeton and NASA