On this day in 1969 – September 21st – during a comet-hunting expedition, Klim Churyumov and Svetlana Gerasimenko discovered the object subsequently named Comet 67P/Churyumov-Gerasimenko.

This was the comet that would later be orbited and studied by ESA's Rosetta Mission.

Mona Evans
For news, activities, pictures and more, sign up to the Astronomy Newsletter!