Hour after hour, night after night, decade after decade all over planet Earth, John Dobson rolled his homemade telescopes to street corners and national parks to show people the heavens. “Look at Saturn,” he would say. “No charge.”

He gave hundreds of thousands of people a fresh view of the stars, prompting Smithsonian magazine to describe him as a “carny barker for the cosmos.” A lanky figure with a ponytail, he toured with his road show in a creaky former school bus, which he called Starship Centaurus A, after a galaxy. It towed one of his bulkier creations, a telescope as large as a midsize automobile.

Mr. Dobson, who died last Wednesday at 98 — or, as he might have put it, 123 days into his 99th orbit around the sun — is credited with developing the first high-powered portable telescope that amateur astronomers could build inexpensively, and tens of thousands have done so. Dobsonian telescopes, as they are known generically, are still a popular item on the market, though Mr. Dobson chose not to benefit from them commercially.

He also founded a stargazing club, Sidewalk Astronomers, which announced his death, in Burbank, Calif. The organization now has chapters on every continent but Antarctica. He wrote books with inviting titles (“Astronomy for Children Under 80” is one) and appeared on Johnny Carson’s “Tonight Show.” In 2005 he was the subject of a documentary feature, “A Sidewalk Astronomer,” directed by Jeffrey Fox Jacobs.