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Science & Technology

The Mystery Of The 'Oumuamua' Asteroid


What is that oblong object that's been sighted in our solar system trying to tell us? That it's just a rock a quarter mile long or some kind of projectile from another place? Is it there to observe, to say hello? Or is that rock just a rock that happens to be oblong? We've turned to the SETI Institute - that's the Search for Extraterrestrial Intelligence. And the senior astronomer there, Seth Shostak, joins us now from SETI HQ in Mountain View, Calif. Mr. Shostak, thanks so much for being with us.

SETH SHOSTAK: My pleasure, Scott.

SIMON: So how would you describe what the telescope detected a few weeks ago?

SHOSTAK: Well, indeed, it is a rock. And it's more like a cigar-shaped rock because it's very much longer than it is in diameter. So it's kind of this long cylinder. But the thing about this rock that actually caught everybody's attention in the beginning was that it was on what's called a hyperbolic trajectory. And that doesn't mean it was exaggerating anything - it just means that it wasn't in the kind of orbit that you would expect from an asteroid or a comet from our own solar system. So indeed, it looks like a visitor from afar.

SIMON: Well, what's it mean?

SHOSTAK: Well, at the very least, it means that, by gosh, other stars also have asteroids - other stellar systems. And maybe you would say, well, of course they would because they're probably like ours. But it's always good to get a little bit of proof that we're not all that special. It looks like this is a rock that was, one way or another, kicked out of its own natal solar system, hurled into space, wandered around for millions, maybe billions of years - you know, just traveling the depths of space - and came into our solar system, which is quite remarkable because it shows that, you know, we have at least company of the rock sort. And, you know, some people like to think, well, maybe it's not a rock. Maybe it's an interstellar craft come to visit.

SIMON: Well, to be blunt, that's why we're calling you - to talk about a rock with possibilities.

SHOSTAK: Well, you know, it could conceivably make sense. It's not impossible to send a huge craft, you know, to other stars. Captain Kirk did it all the time every week at least, OK? And the Starship Enterprise - and this thing kind of looks like it might be an interstellar rocket because it is long and thin, and that would be actually maybe a better shape if you're going through space, and you don't want to hit the debris with a big, wide spacecraft. So, you know, that would be interesting.

But how would you prove that hypothesis? Because if you could, then you could say, well, all right. It's not a rock. We've got cosmic company. What we've been doing for about a month now is turning big antennas that we have for our search for extraterrestrial intelligence in the direction of the rock, hoping to pick up a signal.

SIMON: A signal of some kind of chatter?

SHOSTAK: Yes. I wouldn't speculate on what the signal might be. Who knows what they would be saying? But if you were to pick up a signal that looked like a deliberately produced radio transmission - such as, for example, come from NPR - then you would say, well, you know, we don't know what these guys have in mind, whether they want to join our book club or, you know, tell us something important.

SIMON: (Laughter).

SHOSTAK: But whatever it is, it - you know, there's some intelligence onboard, and this is not just a dumb rock from space.

SIMON: Yeah. Well, if it was our show being heard on board, there'd be a real debate about intelligent life (laughter). But I digress. The object has a couple of names?

SHOSTAK: Well, it did have a name. At first, the thought was, OK. Maybe it's a comet.

SIMON: I should say it has a couple of names we gave it. Who knows what its actual name is?

SHOSTAK: Well, that's right. They may call it Bob. But we call it Oumuamua, which is a Hawaiian name, because this object was found, in fact, at an observatory perched atop Mount Haleakala on Maui. A lot of people go to Maui - probably not to use the telescopes.

SIMON: And also, what is it - A/2017 UI?

SHOSTAK: Yes. It has that designation because once it was seen not to have a tail, which comets typically have - you know, it didn't have stuff it was spewing out into space - then, you know, the designation went from being a comet to being an asteroid. And that's why it says A there - it's an asteroid. But the big question here, Scott, really, is this. Is it an asteroid? And if not, of course, that's the big story. I think it's safe to say that it probably is an asteroid.

There is this tendency, whenever you find something new in space - and after all, that's the job of astronomers - is to find something new in space - but there's a tendency to think, we don't know what this is. So maybe it's alien handiwork. Maybe this is astro-engineering by the Klingons. That would be great, but that has never turned out to be the case. In the end, everything we find has been ascribable to nature, which turns out to be pretty ingenious.

SIMON: Seth Shostak, senior astronomer with the SETI Institute in California, thanks so much for speaking with us. Live long and prosper, as they say.

SHOSTAK: Thank you. Transcript provided by NPR, Copyright NPR.