Oumuamua: Our First Visitor from Another Solar System

Oumuamua: Our First Visitor from Another Solar System


The very first interstellar object passed through the solar system in 2017. Now, three years later, it’s back in the news. Scientists finally think they’ve figured out what it was–and no, it’s not a space ship.

What is Oumuamua?

When a strange, spear-like object was discovered speeding through the solar system, scientists were stumped. Was it an asteroid? A comet? Or perhaps a probe or spacecraft from an alien civilization?

Scientists quickly figured out the object was not. It was dry and rocky, not made of ice like a comet. After being briefly classified as an asteroid, Oumuamua was found to be traveling far too fast to have originated in our solar system.

The shape of the object was unlike anything astronomers had ever seen. Long and narrow, like a stretched-out submarine, it didn’t take a big leap of the imagination to think that the object could be an alien spacecraft. Roughly 400 meters long and only about 40 meters wide, Oumuamua truly seemed like it could be a visitor from another world. And, in a sense, it was.

What’s in a name?

The interstellar object was discovered in Hawaii in 2017. The Pan-STARRS telescope spotted the strange, moving object on October 19th just as it was leaving the solar system. The Hawaiian word means “scout or messenger from our distant past.” Pretty cool, right? Much more fun to say than the official designation 1I/2017 U1.

NASA described the object as an “interstellar vagabond,” which sounds like a jam band that plays a lot of Pink Floyd covers. But the name is less important than the mysteries still surrounding this strange, fast-moving piece of space junk.

What was Oumuamua, really?

Scientists have finally answered the big question about Oumuamua: What the heck is it? According to astronomers Yun Zhang and Douglas N.C. Lin, “Oumuamua came to us after a close encounter with its parent star and that it might, indeed, be a fragment of a shattered alien world.”

When a planet has a “close encounter” with its host star, the resulting tidal forces can literally rip it apart. That’s likely what happened to the fragment that found its way into our region of space. The same thing happened to the comet Shoemaker-Levy 9 when it passed too close to Jupiter.

Zhang and Lin suggest that there could be a huge number of these objects whizzing through space at any time. That brought up an intriguing possibility: “Since these objects may pass through the domains of habitable zones, the possibility that they could transport matter capable of generating life cannot be ruled out. ”

In a way, Oumuamua and objects like it could be a bit like dandelion seeds. Floating through space, carrying the material of far-distant alien worlds to new solar systems.

Is your mind blown? You can learn more about Oumuamua from astrobiologist Karen J. Meech’s TED talk below: