[4][5] He was educated at Palmerston North Boys' High School, and went on to study at the University of Otago, graduating with a Master of Science with second-class honours in 1956.
[4][6] He then undertook postgraduate study at the University of Oxford, earning Master of Arts and Doctor of Philosophy degrees.
[7] On 16 April 1960, Petersen married Patricia Jane Egerton Caughey, and the couple went on to have four children.
[4] In the 1997 New Year Honours, he was appointed an Officer of the New Zealand Order of Merit, for services to the community.
[9] In 2003, Petersen received the Rutherford Medal, the most prestigious award given by the Royal Society of New Zealand.