A New Asteroid Could Be Our Solar System's First Interstellar Visitor

Saturday, 28 October 2017 - 6:02PM
Space
Astronomy
Solar System
Saturday, 28 October 2017 - 6:02PM
A New Asteroid Could Be Our Solar System's First Interstellar Visitor
University of Hawaii/Rob Ratkowski
The asteroid (or possibly comet) A/2017 U1 doesn't have a fancy name, and it isn't very big, just a quarter-mile across. But it's moving fast, and it could be extremely important, as the object that's currently flying through our solar system potentially crossed an immensely vast distance to end up in our corner.

That's what both NASA and a group of astronomers at the University of Hawaii's Pan-STARRS 1 observatory believe: this asteroid might be the first "interstellar visitor" from another star that we've ever found in our own solar system. There's still several questions that still need to be worked out, as A/2017 U1 was only just found on October 19, but it's showing strange behavior which implies that it's not from anywhere around here.

According to a press release from the University of Hawaii, that behavior is both the speed and the extreme angle of its orbit around the sun - the object is flying at 15.8 miles per second, and combining that with its direction, there's a strong chance that it broke into our sun's orbit from interstellar space, and that it'll probably be on its way out before too long. That's why we say "visitor" and not "new roommate."

To get a better idea of just how abnormal its orbit is, take a look at NASA's visualization of that orbit below. Note that it's nearly perpendicular to the plane of our solar system:

 
Astronomer Rob Weryk, the post-doctoral researcher who first identified the object with the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS), talked about its extreme orbit and the few possible explanations for such a phenomenon:

Opening quote
"Its motion could not be explained using either a normal solar system asteroid or comet orbit. This object came from outside our solar system."
Closing quote


We've never managed to record an visitor from beyond our solar system until now - it's likely that some asteroids passed by our neck of the woods at some point in the past few billion years, but we didn't have fancy observatories back then. So this is the first one, once further study manages to confirm it.

The implications are massive here, as there's tons of questions that'll arise regarding an asteroid from a completely different solar system. What's it made out of? How many lightyears has it crossed? Could it be carrying anything else on it? The reason it doesn't have an official name yet is because we've never had to name something like this before, so there's no official naming rules yet. 



Paul Chodas, manager of the Center for Near-Earth Object Studies (CNEOS), is very excited about A/2017 U1, or whatever we end up naming it:

Opening quote
"We have been waiting for this day for decades. It's long been theorized that such objects exist — asteroids or comets moving around between the stars and occasionally passing through our solar system - but this is the first such detection. So far, everything indicates this is likely an interstellar object, but more data would help to confirm it."
Closing quote


Expect more on our strange new visitor soon. Since it's just an asteroid or possible comet, it's not the same as having any living alien visitors, but beggars can't beat choosers, right?

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