[X] My Assistant

[deglr6328]

Eros had 'ponds' of smooth material filling deprssions.  Maybe the  large central smooth area is such a pond here.  Electrostatic processes were thought to be responsible, I think. 

Phil

I think it was recently shown somewhere (nature?) that they were not a result of electrostatic processes but instead were formed when the asteroid was struck by another body (do we call smaller objects striking larger asteroids, "meteors"?) making the whole thing ring like a bell and vibrating fine dust into pools in low lying areas....

[paxdan]

Toma:

Interesting images - the spiky horizon is quite odd, though it may be an artefact of the processing and the direct down-sun illumination.  JAXA have really done well this time!

Bob Shaw

I have a feeling the spiky horizon may well be large boulders, a similar thing was seen in a few of the eros images. However, Ikotawa is so tiny in comparison to everything else we've visited (heck it's smaller than dactly!) the boulders would only have to few tens of meters in size to be very prominant against the horizon.

Can someone photoshop into the image a scale bar or and object we all know the size of so i can get a handle on the size. I reakon we've made manmade objects as big as this lump of rock.

[ElkGroveDan]

Can someone photoshop into the image a scale bar or and object we all know the size of so i can get a handle on the size. I reakon we've made manmade objects as big as this lump of rock.

Apparently it's 630 meters long, which is 2067 feet. The aircraft carrier Eisenhower is 1092 feet long (333 meters). So here's a rough comparison of Hayabusa with two images of the USS Dwight D. Eisenhower.

Doug, perhaps like NASA, I have created a new unit of measure....the aircraftcarrier.

[djellison]

No, no, no, no, no - you've got it all wrong, it's 6 football fields.



Doug

[David]

No, no, no, no, no - you've got it all wrong, it's 6 football fields.

That's 7 football fields for us Yanks with our 90-meter fields.

Personally, I make it out to be a little smaller than the rock of Gibraltar.

[Chmee]

Doug, perhaps like NASA, I  have created a new unit of measure....the aircraftcarrier.

Well, for any Robotech / Macross fans out there, this rock is actuallly half the size of the SDF-1!

Attached thumbnail(s)

 

[antoniseb]

No, no, no, no, no - you've got it all wrong, it's 6 football fields.

We haven't actually built this, but it might be interesting to see it in relation to the 8km long Babyon 5 station.

[paxdan]

Obligatory link to BBC article.

This is turing into quite a coup for JAXA.

Ever since I heard first heard of the notion of a contact binary i always imagined the contact point to be free of dust, i.e., rock in contact with rock. Over the years (eros, ida, etc..) my minds-eye view of bare rock asteroids has been replaced by dusty little worldlets covered in boulders and craters. Of course now looking at Itokawa it makes sense that the dust would gravitate (pun intended) to the contact point as this, for equally sized bodies, would represent the deepest part of the gravity well of the contact-binary system that the dust could fall to (please correct me if i'm wrong).

I am really looking forward to seeing some decent 3D models of this rock. As for sampling both lobes, i would hazard a guess that the dust is going to be pretty homogenous across each site.

Oh and here is a pretty extensive webpage with lots of info about asteroids with satellites and contact binaries

[lyford]

We haven't actually built this, but it might be interesting to see it in relation to the 8km long Babyon 5 station.

Maybe this guy could help....

[Decepticon]

Maybe this guy could help....

I have been a fan of this site for a long time. It has almost all Sci-Fi/ Real Objects comparison charts.


V'Ger is MASSIVE!

[edstrick]

I ran bandpass filtering on the 3 best images to bring out fine details without being swamped in noise. The 2 jpg's from 9/11 have some jpg noise but still show more detail, the better gif from 9/12 crisped up nicely.

Of particular interest, it looks to me like the rough material between protruding knobs is darker than the smooth fines or regolity filling in major depressions and the area between the 2 parts of what really does look like a contact binary. In the bottom image, part of the fill looks like dark rubble and not smooth fines.

Attached thumbnail(s)

 

[dvandorn]

Hmmm... I don't see a lot of albedo difference in the top images between the depression fill and the general fine fill between the two ends of what may well be a contact binary.

The bottom image seems to show, to my eye, a large dark fine fill that could well cover the contact between the two main objects in the contact binary. Yes, there is a rougher and somewhat darker fill in the upper part of the image, and yes, that does look like a somewhat rougher part of the fill between the two bodies. But it very much looks to me that the darker, rougher fill and the slightly lighter fine fill are both performing similar functions, covering the contact point between the two larger masses within the asteroid.

We can now also see many small craters, and it almost seems like these are the largest craters that this body could withstand before it would blow apart into smaller fragments. I'm also thinking that the fine fill might not show craters -- any impact would blow the fines away, and the asteroid's microgravity would, over the course of centuries, draw the fines back into place, obscuring any crater that might have formed.

We need to model the gravitational and trajectoral influences on very small pieces of rock dust liberated from very small bodies, I think. Over the course of centuries and millennia. It would be very instructive to see if rock dust ejected by small impacts on small bodies would tend, over long time periods, to gather back onto those bodies as fines. Because we need to have some decent theories to explain the abundance of fines we're seeing on the surfaces of the asteroids we look at...

-the other Doug

[edstrick]

DVandorn: ".....Yes, there is a rougher and somewhat darker fill in the upper part of the image, and yes, that does look like a somewhat rougher part of the fill between the two bodies. But it very much looks to me that the darker, rougher fill and the slightly lighter fine fill are both performing similar functions, covering the contact point between the two larger masses within the asteroid. ..."

I completely agree. I think one is rubble, the other may be electrostatic-levitation <or whatever> transported dust.

I hope the camera has the S/N ratio to see spectral/color differences between the materials. NEAR's camera was so noisy, it really couldn't see color differences at the single pixel level, and barely could see them over multi-pixel averages. For most bodies in the solar system, other than Earth, Mars, Io, Jupiter, etc., you need to design cameras with a very high signal/noise ratio to be able to do any useful color or multispectral imaging at all.

[Guest_BruceMoomaw_*]

There are at least three current theories as to what could create Eros' "ponds": seismic shaking, electrostatic levitation due to charging of dust particles by solar radiation, and even the idea that Eros -- being a fragment from a bigger asteroid shattered by collision -- may have contained some water ice in its rock pores if it came from that asteroid's interior, and may thus have been gently outgassing water vapor since then and thus swept the dust into depressions: http://www.aas.org/publications/baas/v37n3/dps2005/622.htm . It's perfectly possible that all three mechanisms have operated. One possible fourth one: since there is now a strong feeling that some rubble-pile asteroids are actually split apart by tidal forces when they make a close flyby of a planet, it's possible that more distant flybys by Eros have been tugging dust particles a small distance off its surface, so that they tend to stay more in local depressions when they fall back.

Jeffrey Bell of Hawaii takes the more radical view that Eros' "ponds" may not be dust at all, but pools of solidified lava left over from the asteroid's creation, since he thinks that the S-type asteroids like Eros actually do have a separate origin from the smaller Q-type asteroids that have the same spectral makeup as ordinary-chondrite meteorities. But in that view he's in the minority; most scientists think that the S-type asteroids are indeed made of ordinary-chondrite rock, and that "space weathering" by micrometeoroids and solar radiation have been what's modified their surface near-IR spectra away from those of OC meteorites. And the evidence for the latter does seem to be growing steadily.

[MiniTES]

Could someone make an image highlighting these fill lines so I know exactly what you're referring to? It does look like a contact binary to me...