Roger Clifton Jennison (18 December 1922 29 December 2006) worked as a radio astronomer at Jodrell Bank under the guidance of Robert Hanbury Brown. Jennison made a number of discoveries in the field of radio astronomy, including the discovery of the double nature of radio source Cygnus A (3C 405.0) with M K Das Gupta and the mapping of Cassiopeia A with V Latham. Roger Jennison was born in Grimsby, England in 1922. He was commissioned from RAF aircrew to the Technical Branch-Signals where he developed radar and microwave systems using the Magnetron.