Discovery Rekindles Wish for a Journey to the Stars What will you wear to Alpha Centauri? The news last week that there is a planet circling Alpha Centauri B, only a little more than four light-years away, set off an epidemic of daydreaming among the astronomical and sci-fi set, me among them. For people who believe that interstellar voyages, either for people or for robots, are in the future, Alpha Centauri, a triple-star system that is the Sun's nearest known neighbor, has always loomed large and close as a destination. It was the home of the mythical jungle world Pandora in James Cameron's epic "Avatar," for example. The new planet doesn't have jungles, giant blue-skinned cats or, as far as we know, the magical mineral unobtainium. It is, rather, a hellish unlivable blob of lava probably about the size of Earth, only four million short miles from the fires of Alpha Centauri B, the second brightest star in the system. But if astronomers have learned anything over the last few years from devices like the Kepler satellite, it is that small planets come in packs. There is plenty of room in the system for more planets, habitable ones. "I think we should drop everything and send a probe there," said Sara Seager, an astronomer at M.I.T., echoing a call made last year by the exoplanet pioneer Geoff Marcy of the University of California, Berkeley. There is in fact somebody in charge of doing something just like that. Her name is Mae Jemison, a former astronaut, engineer, dancer, actor and entrepreneur. This year she, in conjunction with the nonprofit foundation Icarus Interstellar, won a $500,000 government grant to set up 100 Year Starship, an organization that is to come up with a business plan for interstellar travel. Darpa, the government agency that helped invent the Internet and now wants to help invent interstellar travel, estimated that just planning for such a trip could take 100 years. Dr. Jemison, 56, hopes it can happen sooner. The Centauri planet was officially announced on her birthday, and over the phone from her new headquarters in Houston she sounded practically bubbly. "I can't imagine a cooler birthday," she said. Dr. Jemison's main work these days is spreading the word and raising money. The prospect of habitable real estate makes the idea of journeying to other stars that much more real, she said, adding: "This is a boon, because most people have heard of Alpha Centauri. It's close. Well, sort of close. Space is deeper and older than most humans can comprehend. You can't measure a light-year by your stride. There are 4.4 of them - 27 trillion miles - from here to Alpha Centauri B. We won't get there by doing business as usual. Voyager 1, the fastest and most distant human artifact, is more than 11 billion miles from the Sun and is speeding away at 11 miles per second; it would take 78,000 years to get to Alpha Centauri if it were going that way, which it is not. Other schemes, based on existing or about-to-be-existing technology like solar sails and thermonuclear rockets, have been proposed that could reach a tenth the speed of light and make the crossing in less than a human lifetime. If you have a design for a faster-than-light warp drive, send it directly to Dr. Jemison, not me. Of course the cost would be staggering, even for the robots (perhaps genetically engineered nanoprobes) that would precede humans. And whoever eventually goes won't ever come back. It won't be me, despite what I once wrote in my high school yearbook: "Ambition: To go to the stars." Perhaps it is a sign of my age that I think more these days about what I would be leaving behind than what I would be gaining: my family and other loved ones, autumn in the Catskills, one more cowboy trout stream or New Year's Eve with old friends. I asked Dr. Jemison if she would go, knowing it was forever. "Yeah," she answered. I would go. Perhaps hearing the catch of loneliness in my voice, she added, "It makes a difference who goes with you." In science fiction, she said, space travel is sterile. "I think it won't be like that," she said. It has to be reimagined. We will bring our culture along with us. All that is part of the Starship study's mandate, she said. At a recent symposium that was a sort of housewarming for the new institute, Dr. Jemison said, there was a lot of talk about what it means to be an interstellar civilization. Do we start calling ourselves Earthlings instead of Americans? Another big topic of conversation, surprisingly or not so surprisingly, was how to dress on a star cruise. As Dr. Jemison pointed out, not all of us are going to look good in those little spandex Star Trek uniforms. And even for those who do, the look will get old after 40 years. Perhaps, some people suggested, we won't need clothes at all on the starship. Everyone would go around in the Band-Aids that passed for underwear in this summer's "Prometheus," Ridley Scott's not-quite prequel to "Alien." But the urge to decorate oneself seems built into human nature. And anyway, the urge to see what concoctions can be worn successfully in zero gravity is likely to be overwhelming. The Japanese fashion designer Eri Matsui has already designed a wedding dress - actually a clever pantsuit - that was worn for a wedding aboard a "vomit comet" flight in 2009. So start shopping and packing - if you dare. Presumably you won't be limited to one carry-on.