Science & Technology

Scientists Have Spotted an Interstellar Visitor to Our Solar System for the First Time

Technically, we've got our very first alien visitor. On October 18, 2017, astronomers spotted the first interstellar object to pass through our solar system. Say hello to A/2017 U1, an outer space traveler taking a shortcut through our neighborhood. But as of November 14, 2017, you can call it by its new name, Oumuamua. The name means "a messenger from afar arriving first" in Hawaiian, an homage to the home of the telescope that first spotted it. Stay for a while, won't you?

Excuse Me, Pardon Me, Just Passing Through

Comets and asteroids aren't usually much to write home about, except when they're alien visitors. Queen's University Belfast scientist Alan Fitzsimmons and an international team began studying asteroid A/2017 U1 (Oumuamua), our solar system's first interstellar tourist, after its October discovery.

"Its motion could not be explained using either a normal solar system asteroid or comet orbit," said Rob Weryk, a postdoctoral researcher at the University of Hawaii Institute for Astronomy (IfA), the first to identify the object using the Pan-STARRS 1 telescope in Hawaii. "This object came from outside our solar system."

We've suspected objects like this have popped through our solar system before and have been looking for them for decades, but seeing one for the first time is something special. "It sends a shiver down the spine to look at this object and think it has come from another star," Fitzsimmons said.

Not All Who Wander Are Lost

Oumuamua entered our solar system from above on a hyperbolic trajectory, moving too fast to be sucked into the sun's orbit. It's a small (about 525 feet across) rocky or icy object that was probably drifting through our galaxy for millions or billions of years before entering our solar system by chance. Sure, maybe it was by chance, maybe it was controlled by a curious extra-terrestrial. Who's to say, really?

Scientists guess this asteroid came from the planet formation around a nearby star. During the process, A/2017 U1 was possibly flung out of the star system. A similar situation went down about 4.5 billion years ago around our own star when Jupiter and Saturn were born. According to Universe Today, some people believe our interstellar visitor may have come from Vega, but more research on the matter is needed.

Other comets have been identified as possibly being from other solar systems (96P/Machholz, for example), but none have been confirmed until Oumuamua. Of course, if you want to be super nitpicky about this whole thing, we'll help you: Half of the atoms in our bodies came from across the universe, technically. But let's just celebrate the matter at hand, okay?

Check out "Asteroid Hunters" by Dr. Carrie Nugent for more on this topic. The audiobook is free with a trial of Audible! Every click helps support Curiosity.

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Written By Joanie Faletto November 4, 2017