Astronomers witness mysterious, never-before-seen disintegration of asteroid

Mar 06, 2014
This series of Hubble Space Telescope images reveals the breakup of an asteroid over a period of several months in late 2013. The largest fragments are up to 200 yards in radius, each with "tails" caused by dust lifted from their surfaces and pushed back by the pressure of sunlight. The 10 pieces of the asteroid drift apart slowly and show a range of breakup times, suggesting that the disintegration cannot be explained by a collision with another asteroid. One idea for the breakup is that the asteroid was accelerated by sunlight to spin at a fast enough rate to fly apart by centrifugal force. The images were taken in visible light with Hubble's Wide-Field Camera 3. Credit: NASA, ESA, D. Jewitt/UCLA

Astronomers have witnessed for the first time the breakup of an asteroid into as many as 10 smaller pieces. The discovery is published online March 6 in Astrophysical Journal Letters.

Though fragile comet nuclei have been seen falling apart as they near the sun, nothing resembling this type of breakup has been observed before in the . NASA's Hubble Space Telescope photographed the demolition.

"Seeing this rock fall apart before our eyes is pretty amazing," said David Jewitt, a professor in the UCLA Department of Earth, Planetary and Space Sciences and the UCLA Department of Physics and Astronomy, who led the astronomical forensics investigation.

The crumbling asteroid, designated P/2013 R3, was first noticed as an anomalous, fuzzy-looking object on Sept. 15, 2013, by the Catalina and Pan-STARRS sky-survey telescopes. A follow-up observation on Oct. 1 with the W.M. Keck telescope on Hawaii's Mauna Kea revealed three co-moving bodies embedded in a dusty envelope that is nearly the diameter of Earth.

"The Keck telescope showed us that this asteroid was worth looking at with Hubble," Jewitt said.

With its superior resolution, the Hubble telescope revealed that there were really 10 embedded objects, each with comet-like dust tails. The four largest rocky fragments are up to 200 yards in radius, about twice the length of a football field.

The Hubble data showed that the fragments are drifting away from each other at a leisurely pace of one mile per hour—slower than a strolling human. The asteroid began coming apart early last year, but new pieces continue to emerge in the most recent images.

This makes it unlikely that the asteroid is disintegrating because of a collision with another asteroid, which would be instantaneous and violent. Some of the debris from such a high-velocity smash-up would also be expected to travel much faster than observed.

Nor is the asteroid coming unglued due to the pressure of interior ices warming and vaporizing, Jewitt said. The asteroid is too cold for ices to significantly sublimate, and it has presumably maintained its nearly 300 million–mile distance from the sun for much of the age of the solar system, he said.

This series of Hubble Space Telescope images reveals the breakup of an asteroid over a period of several months starting in late 2013. The largest fragments are up to 180 meters (200 yards) in radius. Credit: NASA, ESA, D. Jewitt (UCLA)

This leaves a scenario in which the asteroid is disintegrating due to a subtle effect of sunlight, which causes the rotation rate to slowly increase. Eventually, its component pieces, like grapes on a stem, gently pull apart due to centrifugal force, Jewitt said. The possibility of disruption by this so-called "YORP torque" has been discussed by scientists for several years but, so far, never reliably observed.

For this to happen, P/2013 R3 must have a weak, fractured interior, probably as the result of numerous ancient but non-destructive collisions with other asteroids. Most small asteroids, in fact, are thought to have been severely damaged in this way, giving them a "rubble pile" internal structure. P/2013 R3 itself is probably the product of collisional shattering of a bigger body some time in the last billion years.

With Hubble's recent discovery of an active asteroid spouting six tails (P/2013 P5), astronomers are seeing more circumstantial evidence that the pressure of sunlight may be the primary force that disintegrates small asteroids (less than a mile across) in the solar system.

The 's remnant debris, weighing in at 200,000 tons, in the future will provide a rich source of meteoroids, Jewitt said. Most will eventually plunge into the sun, but a small fraction of the debris may one day enter the Earth's atmosphere to blaze across the sky as meteors, he said.

Jewitt, who is on the faculty of the UCLA College of Letters and Science, is a member of the National Academy of Sciences and a fellow of both the American Association for the Advancement of Science and the American Academy of Arts and Sciences. He co-discovered the Kuiper Belt beyond Neptune in 1993. The discovery of the belt, which contains more than a billion objects and was once believed to be empty space, has fundamentally changed the modern perception of the solar system.

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt, Md., manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington.

"Hubble's incredible resolution and sensitivity are creating a new cottage industry for planetary scientists," said Hal Weaver, of the Johns Hopkins University Applied Physics Laboratory in Laurel, Md., one of Jewitt's co-investigators.

Explore further: Hubble sees asteroid spouting six comet-like tails

More information: Paper: arxiv.org/abs/1403.1237

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tadchem
1.6 / 5 (7) Mar 06, 2014
The statement "The asteroid is too cold for ices to significantly sublimate" seems contraindicated by the empirical evidence of the "tails."
GSwift7
4.6 / 5 (9) Mar 06, 2014
The four largest rocky fragments are up to 200 yards in radius, about twice the length of a football field


I wonder if they really meant diameter in stead of radius? It's unusual to see them talk about the radius of asteroids, which are usually irregularly shaped (especially fragments like this). It's more common to discuss the largest and smallest diameter, but oh well.

This would be an awesome target to go have a close look at. We could see what the inside looks like, without having to drill or anything. I know this means there are probably an abundance of pieces just like this scattered around the belt, but seeing all the pieces while they are still close together might be helpful.

I can't help but think that this will be important to understand in the future, when we eventually begin to interact with asteroids in various ways.
GSwift7
4.6 / 5 (9) Mar 06, 2014
The statement "The asteroid is too cold for ices to significantly sublimate" seems contraindicated by the empirical evidence of the "tails."


Those aren't vapor tails. That's just dust, as the article says. The belt is too far out for water to vaporize much, if there's any water inside it in the first place.
Maggnus
3.9 / 5 (7) Mar 06, 2014
The statement "The asteroid is too cold for ices to significantly sublimate" seems contraindicated by the empirical evidence of the "tails."
Perhaps, but given they seem to have been very short lived, perhaps they were simply dissipating dust.
hemitite
4 / 5 (5) Mar 06, 2014
I had it pounded into me as a young Physical Sciences student in middle school, that there was no such thing as centrifugal force, which would be a vector radial to a rotating object that opposed one of equal magnitude pointing inwards towards the object's center of mass. This clearly could not be the case as that would not generate any angular motion, but would simply be a tug of war situation. The correct term in my understanding is centripetal force that results from a vector tangent to the circle of rotation pointing in the direction of rotation along with our old friend the inward pointing vector. I have see this silly throwback term more than once lately - will someone let those sciences writers in on this little secret?
GSwift7
4.4 / 5 (7) Mar 06, 2014
The correct term in my understanding is centripetal force that results from a vector tangent to the circle of rotation


To be really anal about it, the tangential 'force' is inertia. The inward 'force' in this case is probably mechanical strength (and a little bit of gravity), until the inertia overcomes it and the rock cracks apart. You're correct about the terminology mix-up otherwise though.
antialias_physorg
4.3 / 5 (6) Mar 06, 2014
Why would an impact scenario of something very small be out of the question? Such large pieces drifting part mean there is not such a huge change in impulse. Might not a fast, small object penetrate and cause this beast to crack without causing a shrapnell-like explosion?
Maggnus
2.3 / 5 (3) Mar 06, 2014
The statement "The asteroid is too cold for ices to significantly sublimate" seems contraindicated by the empirical evidence of the "tails."


Those aren't vapor tails. That's just dust, as the article says. The belt is too far out for water to vaporize much, if there's any water inside it in the first place.
I was ToSeeked!!
Maggnus
2.8 / 5 (4) Mar 06, 2014
Why would an impact scenario of something very small be out of the question? Such large pieces drifting part mean there is not such a huge change in impulse. Might not a fast, small object penetrate and cause this beast to crack without causing a shrapnell-like explosion?


I'm a little off topic here, but when I first read this I had an immediate flash of a story involving a micro-black hole striking the Earth and creating the Tungusta event. :D

I know that's not what you meant AA, but the thought made me chuckle.
GSwift7
4 / 5 (4) Mar 06, 2014
Might not a fast, small object penetrate and cause this beast to crack without causing a shrapnell-like explosion?


I was wondering along those lines myself. Or, maybe even a larger object with low relative velocity? Those types of collisions are sure to happen. They may have a better reason to rule out a collision than what this article says. Have you checked for a more detailed source?
TheGhostofOtto1923
1.8 / 5 (5) Mar 06, 2014
I wonder if they really meant diameter in stead of radius? It's unusual to see them talk about the radius of asteroids, which are usually irregularly shaped (especially fragments like this). It's more common to discuss the largest and smallest diameter, but oh well.
Im sorry g but, again, youre talking out of your butt.

From the paper itself:

"We take pV = 0.05 to compute effective radii as listed in Table 2. The largest components,
A1, A2, B1 and B2, all have re 0.2 km. Because of dust contamination we only know that
the nucleus radii are rn re and we cannot determine which, if any, of the components in
R3 is the primary (mass-dominant) one."

-which can be found on the INTERNET here:
http://www.spacet...405a.pdf

-But oh well.
TheGhostofOtto1923
1.8 / 5 (5) Mar 06, 2014
In fact
The statement "The asteroid is too cold for ices to significantly sublimate" seems contraindicated by the empirical evidence of the "tails."

Perhaps, but given they seem to have been very short lived, perhaps they were simply dissipating dust.


"All images of R3 taken after October 01 show both a tail of months-old particles in the
direction of the negative velocity vector (west of the nuclei), and tails of new material in the
anti-solar direction (east). The simultaneous presence of tails in both directions is a strong
indication that activity is on-going (>2-3 months)."

-From the paper. I know its just so much FUN to pretend to be carl sagan but you do understand he would be a little annoyed at this compulsion of yours dont you? Especially when your making up your own science from a PRESS release when the original paper is RIGHT THERE, right?
I was wondering along those lines myself.
-But not enough to actually do a little research.

But oh well.
TheGhostofOtto1923
2.6 / 5 (5) Mar 06, 2014
More Mull.
Why would an impact scenario of something very small be out of the question?
"Several observations argue against an impact origin. The separation times of the components
are staggered over several months, whereas impact should give a single time. Ejecta
from an impact should be consistent with a single synchrone date whereas in R3 the fitted
dates differ. The scattering cross-section increases between October 01 and 29 and decreases
very slowly thereafter (Table 2), inconsistent with an impulsive origin. and unlike the bestestablished
asteroid impact event (Scheila, c.f. Bodewits et al. 2011, Jewitt et
al. 2011, Ishiguro et al. 2011). Furthermore, impacts produce ejecta with a broad spectrum
of velocities, from sub-escape to the impact speed (Housen and Holsapple 2011) whereas
our data provide no evidence for fast ejecta, even in the earliest observations. For these
reasons, we suspect that impact does not provide a natural explanation of the properties of
R3..."
Maggnus
3.4 / 5 (5) Mar 06, 2014
-But oh well.
Nothing this crybaby says can be trusted; he is not here to discuss the science, he is here to argue. See here for his real personality!

http://phys.org/n...firstCmt
Maggnus
3 / 5 (4) Mar 06, 2014

-From the paper. I know its just so much FUN to pretend to be carl sagan but you do understand he would be a little annoyed at this compulsion of yours dont you? Especially when your making up your own science from a PRESS release when the original paper is RIGHT THERE, right?
Another example.

See here: http://phys.org/n...firstCmt
TheGhostofOtto1923
2 / 5 (4) Mar 06, 2014
-But oh well.
Nothing this crybaby says can be trusted; he is not here to discuss the science, he is here to argue. See here for his real personality!

http://phys.org/n...firstCmt
Sorry you can post many threads which only prove that I have the highest regard and respect for facts, while you and your croneys have none. Anyone clicking on the above link can see that it takes them to the paper written by the scientists responsible for the work in the above press release.

They can also see that your lazy armchair science in the above thread does not compare to the work these scientists actually did.

When you ignore them you insult them, demean their efforts and display your ignorance all at the same time.

How efficient.

Oh I see arf does not like the smell of your cowpies either. Careful. He has teeth and a finicky bladder.
GSwift7
5 / 5 (6) Mar 06, 2014
Im sorry g but, again, youre talking out of your butt


yeah, when I'm guessing I use words like 'maybe' and 'I think', and I frequently use question marks. Is that okay with you, or do I need prior permission?

-which can be found on the INTERNET here


Oh, sorry. I haven't read the whole thing yet. They just added new stuff on the internet last week and I'm trying to get caught up on that before I read the stuff I missed because of the holidays.

The simultaneous presence of tails in both directions is a strong
indication that activity is on-going


It's still mostly dust, like the article says. There's gonna be a little bit of sublimation, but that's only a minor source of the material in the halo/tails.

They can also see that your lazy armchair science in the above thread does not compare


You're totally right. You are the king of this site and you should totally be a goderator, and they should pay you. You're kinda a big thing around here.
GSwift7
5 / 5 (5) Mar 06, 2014
he is not here to discuss the science, he is here to argue


Yeah, but sometimes it's fun. Think of it like the argument service routine from Monty Python (I'm sure otto can provide the proper name and a link). lol

I take it as a passtime when I'm bored. After all, this is just the comment section of a news almalgamation web site, and he's actually one of the best trolls around here. Sometimes it's nice that he provides good links when I'm too busy playing video games to look them up myself. BTW, have you seen the new Thief game? I'm still on the first playthrough, and I'm not sure how impressed I am yet. Seems to be lacking something.
GSwift7
5 / 5 (5) Mar 06, 2014
Im sorry g


Oh man, I can't believe I missed the opportunity to say:

"It's okay man, I accept."

I'm just not very good at this internet stuff. I should spend some more time hanging around 13 year old kids in first person shooter games, so I can sharpen my skilz.

I have the highest regard and respect for facts, while you and your croneys have none


true. true. Don't be mad bro.
TheGhostofOtto1923
1.7 / 5 (6) Mar 06, 2014
yeah, when I'm guessing I use words like 'maybe' and 'I think', and I frequently use question marks. Is that okay with you, or do I need prior permission?
GOOGLE only has a few more letters to type.
I'm just not very good at this internet stuff. I should spend some more time hanging around 13 year old kids in first person shooter games, so I can sharpen my skilz
Try this guy frankie. 'Ees truly amazin'
http://www.youtub...QUDArFJT
Mimath224
4.7 / 5 (3) Mar 06, 2014
@GSwift7 reading the NASA article the quote is "... The four largest rocky fragments are up to 400 yards in diameter, about four times the length of a football field." but the (larger) image caption still quotes 180m (200yd)...Hmmmm?
Another quote is "...Hubble data showed the fragments drifting away from each other at a leisurely one mph..." and at that v would rule out a collision which should produce larger v.
GSwift7
5 / 5 (2) Mar 07, 2014
GOOGLE only has a few more letters to type


I've heard of them. Do they sell Google at Best Buy, or do you have to download it?

the quote is "... The four largest rocky fragments are up to 400 yards in diameter


Thanks. Since it doesn't make sense to talk about the size of an asteroid in terms of radius in this context, I was wondering if it was a mistake.
EnricM
5 / 5 (2) Mar 07, 2014

... and creating the Tungusta event. :D



Tunguska ;)
cantdrive85
1 / 5 (4) Mar 07, 2014
This leaves a scenario in which the asteroid is disintegrating due to a subtle effect of sunlight, which causes the rotation rate to slowly increase. Eventually, its component pieces, like grapes on a stem, gently pull apart due to centrifugal force, Jewitt said


LOL, sunlight? Fools!
Maggnus
3 / 5 (2) Mar 07, 2014

... and creating the Tungusta event. :D



Tunguska ;)


[face palm[/face palm]
Maggnus
3.4 / 5 (5) Mar 07, 2014
This leaves a scenario in which the asteroid is disintegrating due to a subtle effect of sunlight, which causes the rotation rate to slowly increase. Eventually, its component pieces, like grapes on a stem, gently pull apart due to centrifugal force, Jewitt said


LOL, sunlight? Fools!
Giant electrical bolt? Idiot!
GSwift7
5 / 5 (4) Mar 07, 2014
Giant electrical bolt?


Yeah, 1.21 Jigawatts, which is a result of a natural flux capacitor which forms between the quadrupole layers
Tim Thompson
5 / 5 (5) Mar 07, 2014
LOL, sunlight? Fools!

Let he who is without foolishness cast the first stone. It's called the YORP effect, which is a 2nd order variation on the Yarkovsky effect, where differential thermal emission by a rotating object will alter its rotation. The effect has been known to theory for over 100 years, and has been confirmed by observation as well.

http://en.wikiped...k_effect
http://en.wikiped...y_effect

"Disintegrating Asteroid P/2013 R3"; Jewitt, et al.; Preprint date 5 March 2014, accepted for publication in Astrophysical Journal Letters. This is the paper that reports the results presented here.
http://adsabs.har...03.1237J

Both the Yarkovsky & Yorp effects have been observed.
http://adsabs.har...47A..10D
http://adsabs.har...4421020K
http://adsabs.har...24....1F
TheGhostofOtto1923
2 / 5 (4) Mar 07, 2014
Thanks. Since it doesn't make sense to talk about the size of an asteroid in terms of radius in this context, I was wondering if it was a mistake.
So why do you think the scientists chose to do it that way in the original paper I posted for you?

""We take pV = 0.05 to compute effective radii as listed in Table 2. The largest components,
A1, A2, B1 and B2, all have re 0.2 km. Because of dust contamination we only know that
the nucleus radii are rn re and we cannot determine which, if any, of the components in
R3 is the primary (mass-dominant) one."

-?? Do you think they're working in some context you're not aware of? Could you describe this context you're referring to?
Disintegrating Asteroid P/2013 R3"; Jewitt, et al.;
-which I already posted when I took the original excerpt.
TheGhostofOtto1923
2 / 5 (4) Mar 07, 2014
I think what I'm trying to ascertain g, is why you think using radius 'doesn't make sense' in some context or other when the scientists who wrote the paper the article was written from, used nothing BUT radius?

We note that you didn't say 'apparently ' or 'not that I'm aware of' as anyone might when directed to the original paper, but continued to insist that the scientists themselves were using the wrong term.

Why the fuck would you be so arrogantly dim g? Any idea? I await your reply.
Maggnus
3.4 / 5 (5) Mar 07, 2014
Why would an impact scenario of something very small be out of the question?
Reading the paper, they actually address this question, indicating they do not believe the breakup was the result of impact because
The separation times of the components
are staggered over several months, whereas impact should give a single time.
and
Ejecta from an impact should be consistent with a single synchrone date whereas in R3 the fitted dates differ.
The paper is here: http://www.spacet...405a.pdf in the event you want to read it.
Arf_Arf_Arf_Arf_Arf_Arf
2 / 5 (4) Mar 07, 2014
Dis is funny
[face palm[/face palm]
I could already tell by his aroma that maggnus was two-faced.
Mimath224
5 / 5 (3) Mar 07, 2014
@Tim Thompson, yes quite! Other articles quote something like '...scientists think P/2013 R3's fragmentation is driven by something called the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect...' and '...This indicates that the sun may play a large role in disintegrating these small solar system bodies, by putting pressure on them via sunlight...'. One illustration via NASA shows a highly fragmented surface which gradually breaks up.
antialias_physorg
5 / 5 (3) Mar 08, 2014
The paper is here: http://www.spacet...405a.pdf in the event you want to read it.

Thanks for the link. yes, I see it how they would rule out an impact scenario.
Returners
1 / 5 (1) Mar 09, 2014
It could have been broken up by "tidal" behavior from a close encounter with another object....potentially...

That would produce a more gradual disintegration than a direct impact.

I figure another asteroid would need to pass within a few kilometers of this one's surface in order for that to happen, so that any tidal effect would be strong enough to accelerate some components away from one another..
Uncle Ira
3.3 / 5 (3) Mar 09, 2014
It could have been broken up by "tidal" behavior from a close encounter with another object....potentially...


What this "tidal" behavior is Skippy? Do those asteroid things have both the high and low tides? Maybe you could explain a little more about that, eh? But if it has to do with that n-body stuffs never mind.

Captain Stumpy
3.7 / 5 (3) Mar 09, 2014
What this "tidal" behavior is Skippy?

@Uncle Ira
The tidal force is any of various small gravitational forces acting on an extended body as a result of the varying distance between the source of the gravitational force, such as the moon, and the different parts of the extended body, such as the earth's oceans closest to and farthest from the moon.
The tidal force on a comet/asteroid could come from other asteroids, planets, the sun, etc...

check out these links:

https://en.wikipe...al_force
http://www.thefre...+gravity
Mimath224
3 / 5 (1) Mar 09, 2014
Wouldn't a tidal force strong enough to cause that disruption result in a higher fragment v?
Tim Thompson
5 / 5 (4) Mar 10, 2014
Wouldn't a tidal force strong enough to cause that disruption result in a higher fragment v?

I don't think so. You can always arrange suitably arbitrary circumstances so that the differential force across the asteroid will produce the observed effect. But "arbitrary" is the point, and usually also means "unlikely"; a scenario scripted to produce the desired result, and that is the real weakness of a tidal explanation. On the other hand, the Yarkovsky & YORP effects are not only already well known & understood, but are actually unavoidable by anything that has sunlight shining on it. So, since we know the asteroid *must* feel these effects, it only remains to calculate what those effects should be and compare with observation. The authors do that and find consistency, so it is a viable explanation.
GSwift7
3.7 / 5 (3) Mar 10, 2014
Why the ---- would you be so arrogantly dim g? Any idea? I await your reply


Are you angry?

On the other hand, the Yarkovsky & YORP effects are not only already well known & understood


Does the effect have a preference based on the right hand rule (favoring a counter-clockwise acceleration) or is it entirely dependent on the shape/albedo and orientation?
Tim Thompson
5 / 5 (2) Mar 10, 2014
The Yarkovsky & YORP effects are dependent on shape & albedo (especially albedo variations across the surface), although the shape has the stronger influence of the two. There is no dependency on the right hand rule independent of the spin of the asteroid, which the YORP effect tends to increase over time, regardless of the direction of rotation.
TheGhostofOtto1923
1 / 5 (2) Mar 10, 2014
Are you angry?
Naw just persistent.
Since it doesn't make sense to talk about the size of an asteroid in terms of radius in this context, I was wondering if it was a mistake
So why do you think the scientists chose to do it that way in the original paper I posted for you?

""We take pV = 0.05 to compute effective radii as listed in Table 2. The largest components,
A1, A2, B1 and B2, all have re 0.2 km. Because of dust contamination we only know that
the nucleus radii are rn re and we cannot determine which, if any, of the components in
R3 is the primary (mass-dominant) one."

-?? Do you think they're working in some context you're not aware of? Could you describe this context you're referring to? Why would you think that these scientists would make such a mistake in their peer-reviewed paper, and not one peer would pick it up? Did they all make the same mistake perhaps?
TheGhostofOtto1923
1 / 5 (2) Mar 10, 2014
Perhaps Tim could answer this question for us . Why radius in the paper instead of diameter Tim?
Tim Thompson
5 / 5 (5) Mar 10, 2014
Radius & diameter are essentially the same thing, so it could hardly matter to the analysis which was used. But radius is what we commonly use so they use it. It is easier to use radius, especially if you are going to describe something asymmetric.
Q-Star
5 / 5 (5) Mar 10, 2014
Radius & diameter are essentially the same thing, so it could hardly matter to the analysis which was used. But radius is what we commonly use so they use it. It is easier to use radius, especially if you are going to describe something asymmetric.


Beat me to it. I was going to say, that the reason radius is usually used is because it's a quantity has been used in various operations during analysis, so it is the number that tends to be "on the tip of your tongue". Radius is handier if you have to do any number crunching so it is the first that comes to mind.
TheGhostofOtto1923
1 / 5 (1) Mar 11, 2014
I was going to say, that the reason radius is usually used is because it's a quantity has been used in various operations during analysis
Specifically, in this CONTEXT, radii are used to determine the centripetal forces around the center of gravity which are causing the breakup and the production of dust with observed velocities.

"Breakup may be due to a rotationally induced structural failure of the precursor body.

"Rotational breakup of a strengthless body should occur when the centripetal acceleration on the surface exceeds the gravitational acceleration towards the center.

"Solar radiation provides a torque (the "YORP" torque) capable of driving the spin of a sub-kilometer asteroid to the critical value in less than a million years, making rotational breakup a plausible mechanism"

-Diameter was only extrapolated in the other article to give amateurs something easier to understand.
GSwift7
5 / 5 (2) Mar 11, 2014
So why do you think the scientists chose to do it that way in the original paper I posted for you?


I said "in this context", which is a mainstream news article, where they usually use diameter (maybe because it sounds bigger?), and I frequently see errors when news writers accidentally convert from one to the other. I've pointed out exactly this error in other stories on this site numerous times.

As for the original paper, that's a different context, because as tim and Q pointed out, they actually were doing math.

I was just wondering if the correct term had been used in the NEWS ARTICLE. I didn't say that it was wrong, but it seemed strange to me.

You're very good at searching the internet, so I'm surprised that you're not able to find examples where diameter is used to describe the size of an asteroid. Nearly every popular press article I can find uses diameter:

Here's the wiki page, for example:

http://en.wikiped...Asteroid
GSwift7
5 / 5 (5) Mar 11, 2014
I really do enjoy our talks most of the time, but I don't understand why you're so stuck on such a minor point here. Sometimes your objections are much better than this, but this one is puzzelling to me. I could have checked the original paper myself, but I really didn't feel like it, so I asked if anyone else had read the paper. Is there something wrong with asking if anyone else already knows an answer? If so, what exactly is the problem with that? I'd really like to hear your explanation of this. I'll be eagerly awaiting your reply Otto.
Maggnus
5 / 5 (2) Mar 11, 2014
Is there something wrong with asking if anyone else already knows an answer? If so, what exactly is the problem with that?
Well I suggest it would be because he couldn't then direct a childish stream of bile and belligerence towards you, then lord it over you, preening his feathers of self righteous indignation and claims of moral superiority.

Of course, that's just an educated guess.
flying_finn
3 / 5 (1) Mar 12, 2014
We are in a solar activity cycle. Couldn't they approximate a possible CME for the break-up? Would one have the power to cause the effect?
GSwift7
3.5 / 5 (4) Mar 12, 2014
CME for the break-up? Would one have the power?


Once you get a little bit away from the sun, there's not much actual force behind a CME (over the surface area of an asteroid like this). Even if the radiation or EM flux managed to somehow weaken or crack the asteroid (I don't know how that would work, but we can imagine there's some way we don't know about), it still wouldn't explain the pieces floating away in opposite directions. A CME shouldn't be able to transfer that much kinetic energy to the asteroid. By the time it reaches the asteroid belt, a CME is so spread out that it's probably more like the power of an xray at the hospital, which aren't known to move rocks around much.
antialias_physorg
3.3 / 5 (3) Mar 12, 2014
Even if the radiation or EM flux managed to somehow weaken or crack the asteroid (I don't know how that would work, but we can imagine there's some way we don't know about),

One of the possibilities is that this is a rubble mass that coalesced into a larger object - and is now breaking up. If that is so then it will have been extremely tenuous to begin with (more like a pile of rubble than a homogeneous mass as the amount of gravity holding the parts together is very low)...which in turn would make it far easier to break up than a solid hunk of rock.
TheGhostofOtto1923
1 / 5 (2) Mar 12, 2014
I was just wondering if the correct term had been used in the NEWS ARTICLE
Well I'm not sure what you mean exactly by NEWS ARTICLE, or whether you can cite standards for nomenclature regarding such articles?

A search of a phrase in google shows that it was reprinted in dozens of locations, from pubs like the huffington post to more professionally-oriented sites.

One of these might be the original:
http://sci.esa.in...grating/
http://hubblesite...15/full/
You're very good at searching the internet, so I'm surprised that you're not able to find examples where diameter is used to describe the size of an asteroid. Nearly every popular press article I can find uses diameter
Indeed I am and I did read through that ref. In the CONTEXT of the above article, that being the breakup of this object, the authors selected the proper term.

Learning WHY is what we come here for, yes?
TheGhostofOtto1923
1 / 5 (3) Mar 12, 2014
Even if the radiation or EM flux managed to somehow weaken or crack the asteroid (I don't know how that would work, but we can imagine there's some way we don't know about),
One of the possibilities is that this is a rubble mass that coalesced into a larger object - and is now breaking up. If that is so then it will have been extremely tenuous to begin with (more like a pile of rubble than a homogeneous mass as the amount of gravity holding the parts together is very low)...which in turn would make it far easier to break up
Aa might choose the responsible course and direct the commenter to the original paper which is readily accessible and referenced above, and which OF COURSE addresses exactly what this object IS, how it was formed, and why it may be breaking up.

He could even expend some effort and copy/paste sections of the paper which succinctly address the commenters queries.

Or he can continue to GUESS and MISLEAD like a pompous asshole.
TheGhostofOtto1923
1 / 5 (2) Mar 12, 2014
Once you get a little bit away from the sun, there's not much actual force behind a CME (over the surface area of an asteroid like this). Even if the radiation or EM flux managed to somehow weaken or crack the asteroid
Ditto for Gswift.

"Solar radiation provides a torque (the "YORP" torque) capable of driving the spin of a sub-kilometer asteroid to the critical value in less than a million years, making rotational breakup a plausible mechanism for R3 and other small asteroids (Marzari et al. 2011)"
antialias_physorg
4.2 / 5 (5) Mar 12, 2014
Weird: The paper does say:
For these reasons, we suspect that impact does not provide a natural explanation of the properties of R3, although we cannot rule it out.


Weird: The paper does not say what it is or how it was formed (other that its color is consistent with a C-type asteroid...which means not much in terms of how solid it is).
You sure you even read the paper?
and which OF COURSE addresses exactly what this object IS, how it was formed, and why it may be breaking up.

Neither do they make a definite statement on why it is breaking up - they only rule out (or show that probability is low) for some scenarios.

Again: You sure you read the paper?
TheGhostofOtto1923
1 / 5 (2) Mar 12, 2014
does not say what it is or how it was formed
"consists of 10 or more distinct components... we describe initial observations taken to establish the basic properties of this remarkable object... sublimation gas pressure cracking is not a viable mechanism, although, if ice does exist in R3, its exposure after break-up could contribute to the continued dust production... a strengthless body... P/2013 P5 is episodically shedding only its regolith while the multiple components of R3 indicate that a more profound structural failure has occurred... classification as a primitive C-type body..."

-Ah. I see this is where aa got hung up (more research needed).
http://en.wikiped...asteroid

-where one can find origin, composition, etc.

-The paper tells us: low to no ice, no structural integrity (strengthless), failure due to spinup from solar radiation.

But hold on...
TheGhostofOtto1923
1 / 5 (2) Mar 12, 2014
One of the possibilities is that this is a rubble mass that coalesced into a larger object - and is now breaking up
From the article...

"This leaves a scenario in which the asteroid is disintegrating due to a subtle effect of sunlight, which causes the rotation rate to slowly increase... For this to happen, P/2013 R3 MUST have a weak, fractured interior [strengthless], probably as the result of numerous ancient but non-destructive collisions with other asteroids. Most small asteroids, in fact, are thought to have been severely damaged in this way, giving them a "rubble pile" internal structure. P/2013 R3 itself is probably the product of collisional shattering of a bigger body some time in the last billion years... The asteroid's remnant debris, weighing in at 200,000 tons..."
Again: You sure you read the paper?
You sure you read the article?

Weird.
marklade
Mar 12, 2014
This comment has been removed by a moderator.
antialias_physorg
4 / 5 (4) Mar 13, 2014
does not say what it is or how it was formed
"consists of 10 or more distinct components...

After breakup. This tells us nothing if it was one part or just a loose association of objects that recently separated (for whatever reason). Nor does it say anything about formation.
They make some guesses as to internal makeup - but there is nothing definite in there and NOTHING at all as to formation and origin (as you claimed.)

where one can find origin, composition, etc.

I think you need to take a reading comprehension class: they say "spectra consistent with a c-type asteroid"...not "is a c-type asteroid". That are two different types of statements. Scientific papers are weird that way: people actually say what they mean - not say what you want to interpret. Scientists are precise that way.

So you might want to take pause and try to learn how to read scientific papers (or sweat that little thing people call 'comprehension')
GSwift7
5 / 5 (2) Mar 13, 2014
I think you guys mis-understood my last comment.

I was answering flying_finn's suggestion that a CME somehow broke the asteroid apart. I don't think any single CME had any effect here, and I was trying to explain to flying_finn why a CME wouldn't be able to trigger an asteroid to fly apart.
TheGhostofOtto1923
1 / 5 (1) Mar 13, 2014
breakup. This tells us nothing if it was one part or just a loose association of objects that recently separated (for whatever reason). Nor does it say anything about formation.
They use a few different methods to classify it as a typical C type asteroid. As they state on the wiki page, these are usually, as far as they know, rubble piles (strengthless). They calculate how much sunlight is needed to spin such an asteroid up to failure and they find that their predictions match what they observe.
This tells us nothing if it was one part or just a loose association of objects that recently separated (for whatever reason)
"Eventually, its component pieces, like grapes on a stem, gently pull apart"

-I can keep dropping in quotes or you can read it again and see that their understanding is that this was a single C type asteroid that has recently broken up due to sunlight-induced rotation.
TheGhostofOtto1923
1 / 5 (1) Mar 13, 2014
I think you need to take a reading comprehension class: they say "spectra consistent with a c-type asteroid"...not "is a c-type asteroid". That are two different types of statements. Scientific papers are weird that way: people actually say what they mean
"The unit of measurement usually given when talking about statistical significance is the standard deviation, expressed with the lowercase Greek letter sigma (σ). The term refers to the amount of variability in a given set of data: whether the data points are all clustered together, or very spread out... In most cases, a five-sigma result is considered the gold standard for significance, corresponding to about a one-in-a-million chance that the findings are just a result of random variations; six sigma translates to one chance in a half-billion that the result is a random fluke."

-The term 'consistent with' does not connote a specific level or 'type' of confidence.

Active asteroids
http://arxiv.org/abs/1112.5220
TheGhostofOtto1923
1 / 5 (1) Mar 13, 2014
This tells us nothing if it was one part or just a loose association of objects that recently separated (for whatever reason)
"... if ice does exist in R3, its exposure after break-up could contribute to the continued dust production... The separation times of the com- ponents are staggered over several months whereas impact should give a single time... unlike the best- established asteroid impact event... impact does not provide a natural explanation of the properties of R3... the rotational equator of the disrupted parent body. Rotational instability is a potential source of bound (e.g. Walsh et al. 2012) and unbound asteroid pairs (Jacobson et al. 2014, Polishook et al. 2014) and of chaotic systems in which mass is both re-accreted and shed from interacting ejecta... the multiple components of R3 indicate that a more profound structural failure has occurred..."

-These statements are all consistent with a single body that has only recently broken up.
TheGhostofOtto1923
1 / 5 (1) Mar 13, 2014
-And this is confirmed for us in the summary section.

"Asteroid P/2013 R3 is split into at least 10 fragments, the largest of which have effective radii 200 m (geometric albedo 0.05 assumed). The fragments exhibit a velocity dispersion 0.2 to 0.5 m s−1 and their motions indicate break-up dates in the range 2013 February to September."

-Which was not very long ago at all was it ?
TheGhostofOtto1923
1 / 5 (1) Mar 13, 2014
read scientific papers (or sweat that little thing people call 'comprehension')
I can understand your apparent confusion in reading that statement from the summary section. At first glance it may appear that the authors are talking about secondary break ups of the component objects because the plural 'dates' is used.

But on further examination we see that they are talking about 'velocity dispersion' of these components away from each other and we can conclude that they are telling us that, per their current understanding, the breakup of the parent body was a complex event comprised of multiple separations occurring on a timeline between the dates of 2013 feb through sept.

Roughly speaking.