Percival Lowell spent nights mapping intricate alien megastructures on Mars, and while sketching Venus he inadvertently drew the blood vessels inside his own eyeball. This same man revolutionized modern observational astronomy and built the infrastructure and math that led to the discovery of Pluto.

This deep dive explores how one person could be so brilliantly right and so spectacularly wrong, tracing Lowell from Boston Brahmin industrialist and East Asia diplomat to the founder of a mountaintop observatory in Flagstaff, Arizona.

• His early career photographing Korea's King Gojong and writing acclaimed books on Eastern culture
• His revolutionary choice to build an observatory at high altitude for optimal seeing
• How mistranslation and the brain's pattern-seeking produced the illusory Martian canals
• The Venus ...