An unusually bright object was visible traveling across the sky at around 9:47 p.m. Pacific time on 27 July 2016: 

There was speculation that the object, which was reported from Colorado to California, was an unidentified flying object, a plane, or a meteor from the annual Delta Aquarid shower, which was especially active during that same timeframe.  

Astronomer Phil Plait said despite the shower, the object likely wasn’t a meteor at all (but still not the mothership):

Scientist Jonathan McDowell from the Harvard-Smithsonian Center for Astrophysics further narrowed down what the object might have been: