Due to its location, sunlight reaches the rim of this crater at a very low angle, leaving the interior in permanent darkness.

As a result, the crater floor has never been observed by orbiting spacecraft, although it has been roughly mapped by radar.

The lack of illumination by the Sun, the interior remains at a permanent temperature below 100 kelvins, cold enough to trap any water vapor that reaches the crater following comet impacts on the Moon.

The Lunar Prospector spacecraft carried a neutron spectrometer that could be used to detect the presence of large concentrations of hydrogen.

The cold trap within Faustini was identified as having a high concentration of hydrogen, relative to the norm for the lunar surface.