Images of strange solar system visitor peel away some of the mystery

Images of strange solar system visitor peel away some of the mystery
Images of an interloper from beyond the solar system — an asteroid or a comet — were captured on Oct. 27 by the 3.5-meter WIYN Telescope on Kitt Peak, Ariz. Credit: WIYN OBSERVATORY/RALF KOTULLA

A strange visitor, either asteroid or comet, zipping through our solar system at a high speed is giving astronomers a once-in-a-generation opportunity to examine up close an object from somewhere else in our galaxy.

"It's a really rare object," explains Ralf Kotulla, a University of Wisconsin–Madison astronomer who, with colleagues from UCLA and the National Optical Astronomy Observatory (NOAO), used the 3.5 meter WIYN Telescope on Kitt Peak, Arizona, to take some of the first pictures of the solar system interloper.

The object, known to astronomers as 1I/2017 U1, measures 180 meters by 30 meters. In shape, the object resembles a fat cigar, half a city block long, and was first discovered Oct. 19 by astronomers at the University of Hawaii combing the sky for near-Earth objects. Since then, astronomers who have access to telescope time have been zooming in on the object to see what they might learn.

According to Kotulla, the interloper is speeding through the solar system at an astonishing 40,000 miles per hour. The high rate of speed and the orbit of the object could not be explained in the context of more run-of-the-mill comets or asteroids in our solar system.

1I/2017 U1 dropped into our solar system from "above" the ecliptic, the plane where most planets and asteroids orbit the sun, and is now skipping away from the solar system, headed back to interstellar space.

"This object has considerable speed. It is not bound to the sun" like comets or asteroids native to our solar system, Kotulla explains. "Its orbit doesn't take it anywhere near the major planets."

The WIYN Telescope made its observations of 1I/2017 U1 on Oct. 27 shortly after the object's closest pass to Earth. The WIYN team's findings are reported online this week (Nov. 13, 2017) in a preprint on Astro-Ph. The gist of the report is that 1I/2017 U1—aside from its origin beyond the solar system, its unusual orbit and shape, and high rate of speed—is unremarkable when its physical properties are compared to similar objects from our own solar system.

Because it is so small and moving at such a high rate of speed, the object, even to a relatively large telescope like WIYN, appears faint, a fuzzy spot on a background of stars. The combination of being faint and fast means that 1I/2017 U1 is unlikely to be observed by amateur astronomers, the cadre of sky watchers that typically identifies new comets or asteroids sweeping close to Earth.

Images of strange solar system visitor peel away some of the mystery
This animation shows the path of the asteroid — or perhaps a comet — as it passed through our inner solar system in September and October 2017. From analysis of its motion, scientists calculate that it probably originated from outside of our solar system. Credit: NASA/JPL-CALTECH

From the WIYN observations, no coma—a nebulous envelope of dust and gas created when comets heat up as they pass near the sun—is apparent. The WIYN team also failed to see a tail, the signature feature of a .

But the absence of the fuzzy halo and a detectable tail, notes Kotulla, does not mean that it isn't a comet.

"That's one of the questions we're trying to answer," says the Wisconsin . "Comet or asteroid?"

Images of strange solar system visitor peel away some of the mystery
The WIYN telescope building against a sunset sky, with interior light on the telescope. Credit: MARK HANNA/NOAO/AURA/NSF

The WIYN observations revealed that the object is elongated in shape and rotates on an axis about once every eight hours. From the perspective of Earth, the is seen sideways and, as it spins on its axis, end-on, explaining variations in brightness as sunlight is reflected off the comet or asteroid. It also has a reddish tinge and a low albedo, suggesting 1I/2017 U1 lacks the coating of ice that many comets acquire as they spend most of their time in cold storage in the outer reaches of the solar system.

The upshot of the WIYN observations, says Kotulla, is that the visitor from some distant planetary system, beyond its robusto-cigar shape, looks very much like the objects that populate our own solar system.


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Nov 16, 2017
"Rendezvous with Rama is a science fiction novel by British writer Arthur C. Clarke first published in 1973. Set in the 2130s, the story involves a 50-kilometre (31 mi) cylindrical alien starship that enters Earth's solar system.

"The "Rama" of the title is an alien starship, initially mistaken for an asteroid categorised as "31/439". It is detected by astronomers in the year 2131 while it is still outside the orbit of Jupiter. Its speed (100,000 km/h)..."

Nov 17, 2017
TGO1, what exactly does a fictional story have to do with the reality of this present event?

As your therapist would tell you "Sometimes a cigar-shaped asteroid is just a cigar-shaped asteroid."

Nov 17, 2017
TGO1, what exactly does a fictional story have to do with the reality of this present event?
You do seem to be lacking in various faculties. One of them apparently is imagination.

Nov 18, 2017
Again I ask... What does an old fictional story, based upon obsolete knowledge and fanciful assumptions? Have to do with this present day article based upon preliminary observations?

Cause yes, the stories can be entertaining and/or relaxing.

However, we should learn how to separate the 'fun' from the 'facts'. Just to avoid confusing ourselves.

Nov 18, 2017
TGO1, what exactly does a fictional story have to do with the reality of this present event?

As your therapist would tell you "Sometimes a cigar-shaped asteroid is just a cigar-shaped asteroid."


Bloody good book, though. I recommend it, if you've never read it.
https://en.wikipe...ith_Rama

Nov 19, 2017
Again I ask... What does an old fictional story, based upon obsolete knowledge and fanciful assumptions? Have to do with this present day article based upon preliminary observations?
What makes you think O'Neill tubes are fanciful assumptions?
Bloody good book, though. I recommend it, if you've never read it
Yeah you bet. Lots of good hard science, as in parameters for trying to rendezvous with an interstellar interloper.
However, we should learn how to separate the 'fun' from the 'facts'
rwillikers is not aware of how much science was first proposed in speculative fiction. As in comsats invented by Arthur c clarke.

Rwillikers is a noob who doesnt know how often sci-fi comes up in these threads, or how useful it can be in understanding concepts or real-world implications of science.

Nov 19, 2017
how much science was first proposed in speculative fiction
Isaac Asimov - a true genius
...is a noob who doesnt know how often sci-fi comes up in these threads, or how useful it can be in understanding concepts or real-world implications of science
-OR-
because the site is already flooded with pseudoscience idiocy because they've taken over and run out most of the better posters, he assumed you were promoting said pseudoscience?

.

to some, sci-fi is great when it's written well with plausible science in it, like said Asimov, etc
but some folk just don't do fiction

IMHO - i have found that as i age and study science, i prefer non-fiction over fiction as it's far more interesting and fascinating. i've not bought or read a sci-fi book in years (Clarke and Asimov being the last ones i read - again - a few years back)

Nov 19, 2017
If my feeble old memory serves, Clark and Asimov and many other writers of classical science fiction also published science fact papers and articles, texts and books.

Tiz a puzzlement why those scientists and engineers and all-around tech-educated types bothered to separate the genres. Is that really the impression of innate gibberish the commentators to this site wish to boast of?

Perhaps those GA writers were smart enough to figure out the differences between fiction and factual?

Personally, I do read a lot of what is sold as modern science fiction.

An ennui inspiring avalanche of poorly written alt-right propaganda stinks up the whole field. I mean, when you inquire of the idiot's "Why did you confuse the Baltic States and the Balkan States? Didn't you know, past the Earth's atmosphere, the stars do not twinkle?"

They actually brag and crow about their ignorance, as if not knowing simple geography or science is a good thing. Proof of their ideological purity.

Nov 20, 2017
non-fiction over fiction as it's far more interesting and fascinating. i've not bought or read a sci-fi book in years (Clarke and Asimov being the last ones i read - again - a few years back)
Me neither. I watch sci-fi movies and 'let's play' youtube vids and see how speculators incorporate science into every day situations. Like iron mans suit tech or blade runner replicants or The Martian.

I like to imagine what 3D will be like in 20 years, when we're watching direct 360 degree feeds from Martian helmets. I want to see what Io looks like from the surface.

And I appreciate all the informed artists on par with niven and asimov who have the tools to show me what these things might look like.

"Imagination is more important than knowledge. For knowledge is limited, whereas imagination embraces the entire world, stimulating progress, giving birth to evolution." Einstein

-And I think it makes me an optimist unlike so many stogy posters here [eikka, antialiens]

Nov 20, 2017
Me neither. I watch sci-fi movies and 'let's play' youtube vids and see how speculators incorporate science into every day situations
i just can't... i don't mind the occasional vid, but my bibliophilia even gets in the way with digital books

i'm just not so much a TV fan - too poor to pay atten - Oh look! coffee!
-And I think it makes me an optimist unlike so many stogy posters here [eikka, antialiens]
if you're talking about antialias_physorg, then i think you're off... he is pretty optimistic from what i can tell
And I appreciate all the informed artists on par with niven and asimov who have the tools to show me what these things might look like
ditto


Nov 20, 2017
Jeez, folks. It was just a chunk of Krypton's crust. Why all the animus?

Nov 20, 2017
Well this is strange

"... to observe the unique space rock, known as 'Oumuamua, before it fades from view.
Their results so far suggest it is at least 10 times longer than it is wide."

"...the object was about 400m long, rapidly rotating and subject to dramatic changes in brightness."

"Also, one has to realise we don't know where the rotation pole is pointed. We assumed that it was perpendicular to the line of site. If it were tipped over at all, then there are projection effects and the 10:1 is a minimum. It could be more elongated!"

"Sometimes... contact binaries... but even so, the pieces would be longer than most things in the Solar System, and our analysis shows that it is rotating fast enough that they should not stay together."

"...dense, comprised of rock and possibly metals..."

-Gee willikers.

"A #2 General Products hull is a cylinder 300 feet long and 20 feet wide, pointed at both ends and with a slight "wasp-waist" constriction near the tail."

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