What you learned in school
Astronomy textbooks included detailed maps of Martian "canals" drawn by prominent astronomers like Percival Lowell. Students learned about sophisticated engineering projects built by Martian civilization to transport water across the planet's surface. These linear features were presented as definitive evidence of intelligent life on Mars, with textbooks describing elaborate irrigation systems and advanced Martian society.
What we know now
Astronomy textbooks included detailed maps of Martian "canals" supposedly built by an advanced civilization. Students learned about Percival Lowell's observations and theories about Martian engineering projects to transport water across the planet. These linear features were considered evidence of intelligent life. Better telescopes and space missions revealed that the "canals" were optical illusions caused by the human brain's tendency to connect random features into patterns. Mars shows no evidence of current or past intelligent life, though it may have once had microbial life.