Americanastronomer, brother of V. M. Slipher. He was a pioneer of planetary photography, achieving a quality rarely surpassed in his lifetime. He obtained unique sequences of photographs of Mars, Jupiter, and Saturn in which changes in visible features can be traced through over 50 years of favourable oppositions. He was one of the first to appreciate the benefits in astrophotography of stacking several negatives together to achieve a highly detailed print.
Subjects: Astronomy and Astrophysics.