On the campus of the University of Southern California, the morning sun illuminated an inflatable replica of a white space station fit for human habitation. The little sign next to it declared: “Mars: The time has come!”

Starting on Oct. 9, astronomers, robotics engineers and planetary scientists stepped past the sign on their way to a three-day convention held by the Mars Society. They were joined by high school students, sci-fi aficionados and I.T. guys — people who did not work in the space industry yet were bonded by their desire to look up at the stars and wonder: What’s out there? And: When can I go?

They sipped coffee outside a lecture hall while exchanging LinkedIn contacts and discussing which presentations they would attend, among them “Debating the Martian Constitution” and “Brewing Quality Coffee on Mars.” Souvenirs for sale included Elon Musk socks, boxers with Hubble Space Telescope images and hoodies that read “Occupy Mars.”

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