Story by Ilima Loomis
Karen Meech had just returned to Honolulu from a conference and was looking forward to some downtime when the phone rang. It was Richard Wainscott, head of the Pan-STARRS telescope. The asteroid-scanning observatory on Haleakalā had just detected something unprecedented—a strange object hurtling toward our solar system. “Something was a little odd about this one,” recalls Meech, a planetary astronomer and astrobiologist at the University of Hawai‘i Institute for Astronomy.
The object careening toward us was an asteroid from another star system—the first known object to enter our solar system from interstellar space. “My thought was, we need to get all the telescope time we possibly can, immediately,” Meech says. The object was coming in fast, and would leave just as quickly. Since it only shines with reflected sunlight, each time it doubled its distance from the sun, it would get 10,000 times fainter. “In the end, we had less than two weeks when the object would be bright enough to characterize it,” she says.
To get a closer look at this strange object and “characterize” it—learn its size, shape, spin, density, and, if possible, what it might be made of—Meech and her team of scientists would need to look at it with some of the world’s most powerful telescopes, and fast. It can take as long as six months to get access to a major telescope, but observatory directors typically set aside discretionary time for last-minute events like this. The team ended up getting time on telescopes on both Mauna Kea, on Hawai‘i Island, and in Chile, and then raced to study it, compressing the usual weeks of analysis into a few days. “Between learning about it and submitting the paper to [the journal] Nature was nine days,” Meech says.
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Just one thing was missing: the asteroid needed a name—something with a little more gravitas than “1I/2017/U1,” its technical designation. Ka‘iu Kimura, director of the Imi Loa Astronomy Center in Hilo, and her uncle, UH–Hilo Hawaiian-language professor Larry Kimura, came up with ‘Oumuamua. “It means a messenger or scout,” Ka‘iu explains. Meech asked for expedited approval of the name from the International Astronomical Union—and got it in time for publication in Nature on November 20.
Meech says the name is perfect. “This really is a voyager from somewhere else, and this may be its first passage close to a star since it left its home star system,” she says. “It’s just like the voyagers from Polynesia who set out from home, not knowing if they would make landfall.”