Mark Rober is an American engineer, inventor, and popular YouTuber known for his engaging science and engineering videos. He worked for NASA for nearly a decade, contributing to projects like the Mars Rover. After leaving NASA, he focused on creating educational content that makes complex concepts accessible and entertaining. Rober's YouTube channel features a variety of projects, including creative gadgets and experiments. He is particularly famous for his innovative Halloween costume ideas and the viral squirrel obstacle course video. His work emphasizes the importance of science, technology, engineering, and mathematics (STEM) education for young audiences.