UFO Sighting in Hayward, California on 2017-06-18 22:05:00 - Rectangular object, rotating (1 rev/3 secs) straight trajectory. no lights.

Sunday, june 18, 2017, 10:05 pm. viewing stars using good pair of 7x50 binoculars. had lowered binoculars, when movement caught my eye. remainder of sighting was through these binoculars. sighted object travelling from due north (below polaris) to ssw. faded from view as it passed about 2 finger width below jupiter. object displayed no lights. my impression was that it was visible due to reflected city lights, no "internal" illumination. object appeared dull grey, not shiny. object was rectangular, but with rounded corners, no "thickness" visible. object was rotating, about 1 revolution per 2-3 seconds. object was travelling in a straight line. my guess - altitude 1500 to 2500 ft, speed 250 - 350 mph. i am comparing this object to light aircraft arriving and departing from hayward regional airport. no noise, no visible "trail", no heat signature.