Education
He was educated at the University of Wales, Swansea, receiving his Bachelor of Science in 1970. He then earned a Doctor of Philosophy in geology from Michigan State University in 1974.
He was educated at the University of Wales, Swansea, receiving his Bachelor of Science in 1970. He then earned a Doctor of Philosophy in geology from Michigan State University in 1974.
His post-doctoral work was performed at the Smithsonian Astrophysical Observatory. Doctor Ryder worked at the National Aeronautics and Space Administration Johnson Space Center in the Lunar Curatorial Facility for Northrup Services Incorporated. From 1978 to 1982 he helped in the assembly of catalogues and guides to the Apollo lunar samples.
Since 1983 he was a staff scientist at the Lunar and Planetary Institute in Houston, Texas.
Much of his work concerned the geology of the lunar surface, including the history of the mare volcanism, Petrology of lunar rocks including highland rocks and breccias, and the chronology of lunar bombardment. He was an advocate of the "3.8 Georgia Cataclysmic Bombardment" theory concerning a period of sudden mass impacts of the moon and inner planets.
A crater on the Moon has been named in his honour. The crater is located at 44.5°South, 143.2° East, east of the crater Pauli.