ESA
Gerst, a European Space Agency (ESA) astronaut from Germany, took the photos during a six-month mission last year that ended in November.
He's been shooting his surroundings while working at ISS and these pictures are a spooky insight into the research centre after hours, capturing the silent, floating world of living in space.
In October, the ESA reported that Gerst left the relative safety of the station to venture into open space with NASA astronaut Reid Wiseman - a brave guy.