[X] My Assistant

[djellison]

I made this during a debate with a conspiracists anomalist loon on a forum elsewhere...but I thought I'd share it here just because..well..it's cool

http://www.unmannedspaceflight.com/doug_im...ear_feature.gif

Doug

[Marcel]

Waaah ! That's pretty cool indeed ! What's the scale we're looking at here ?

I have 2 horizontal "seams" in the images in the end of the animation though.
Is that me, or your "Gericom" ? I often wondered, would it be possible to fill in the images in between, so that it runs smoothly, without shocks ? Is there any software that can generate these "gaps", so that it runs at 24 images a second ?

[djellison]

I think the seams are a result of stuttering on playback - sometimes I get it - sometimes I dont

I wouldnt want to really go and fudge frames inbetween the ones that were taken - it wouldnt tell us anything new

I was inspired to go find more based on this

http://near.jhuapl.edu/iod/20000503/index.html

The f.o.v. is about a mile

Doug

[Marcel]

I wouldnt want to really go and fudge frames inbetween the ones that were taken - it wouldnt tell us anything new

I agree. But i thought it might be more easy (and comfortable) to follow a particular feature then, because it isn't "jumping", but "flowing".....but hell: it;s a great sequence and there's always something to comment on. You can hate me now

[edstrick]

You don't have to interpolate frames in coarse time-step movies if the object imaged isn't changing much between frames.. you basically have to make short mosaic segments and steadily pan the reconstructed field of view along the sequence, going from perfect registration with one image's center to the next image's center and so on.

[Chmee]

I made this during a debate with a conspiracists anomalist loon on a forum elsewhere...but I thought I'd share it here just because..well..it's cool
Doug

Would that be Space.com's forum *cough*

[djellison]

Nope - somewhere else

doug

[ljk4-1]

NEAR mission images give clues to composition of asteroid Eros

July 22, 2005

Writer: Lauren Gold
Phone: (607) 255-9376
E-mail: lg34@cornell.edu

Media Contact: Press Relations Office
Phone: (607) 255-6074
E-mail: pressoffice@cornell.edu


ITHACA, N.Y. -- An asteroid's external features, when analyzed carefully, can say a lot about its interior. So it was while he was mapping the surface of the asteroid 433 Eros that Peter Thomas, a senior research associate in astronomy at Cornell University, found a simple solution to an earlier puzzle about the asteroid's composition.

Thomas was using images collected by the Near Earth Asteroid Rendezvous mission in 2001 to create a digital map of Eros. On the asteroid's surface, predictably pock-marked with thousands of craters accumulated from impacts over its lifetime, he saw a feature first noticed by Cornell graduate student Marc Berthoud: that a few particular patches were inexplicably smooth. That observation had led to various theories -- but none that seemed completely satisfying.

In a letter appearing in the current issue of the journal Nature (Vol. 436, No. 7049, p. 366), Thomas and Northwestern University geologist Mark Robinson show that the asteroid's smooth patches can be explained by a seismic disturbance that occurred when the crater, known as the Shoemaker crater, was formed.

The fact that seismic waves were carried through the center of the asteroid shows that the asteroid's core is cohesive enough to transmit such waves, Thomas says. And the smoothing-out effect within a radius of up to 9 kilometers from the 7.6-kilometer Shoemaker crater -- even on the opposite side of the asteroid -- indicates that Eros' surface is loose enough to get shaken down by the impact.

Asteroids are small, planetlike bodies that date back to the beginning of the solar system, so studying them can give astronomers insight into the solar system's formation. And while no asteroids currently threaten Earth, knowing more about their composition could help prepare for a possible future encounter.

Eros, whose surface is a jumble of house-sized boulders and small stones ("what geologists call 'poorly sorted,'" says Thomas), is the most carefully studied asteroid, in part because its orbit brings it close to earth.

Thomas and Robinson considered various theories for the regions of smoothness, including the idea that ejecta from another impact had blanketed the areas. But they rejected the ejecta hypothesis when calculations showed an impact Shoemaker's size wouldn't create enough material to cover the surface indicated. And even if it did, they add, the asteroid's irregular shape and motion would cause the ejecta to be distributed differently.

In contrast, says Thomas, the shaking-down hypothesis fits the evidence neatly. "The classic light bulb goes on in your head," he says; the crater density of small craters increases with the distance from the Shoemaker crater. "Simple geometry says something like a simple seismic wave."

The NEAR mission, in which a NASA spacecraft landed on the asteroid's surface in 2001 after orbiting it for a year, yielded more than 100,000 images of the small asteroid. (Eros is about 33 kilometers long, 13 kilometers wide and 8 kilometers thick). Since the mission's conclusion 16 days after the landing, scientists from institutions around the world have been sorting through the data.

That process is expected to continue for years. "Careful mapping of things on the surface can give you a good clue as to what's inside," says Thomas. "And in one sense, we've barely begun."


Related World Wide Web sites:

Cornell University Department of Astronomy:

http://www.astro.cornell.edu/

Seismic resurfacing by a single impact on the asteroid 433 Eros (Nature)

http://www.nature.com/nature/journal/v436/...ature03855.html


-30-

The web version of this story, with accompanying photos, is available at

http://www.news.cornell.edu/stories/July05...s.Eros.lxg.html
--

Cornell University News Service
312 College Ave.
Ithaca, NY 14850
607-255-4206
cunews@cornell.edu
http://www.news.cornell.edu

[ElkGroveDan]

during a debate with a conspiracists anomalist loon on a forum elsewhere...

OK now that you've piqued our interest, can we have a hint as to what the conspiracists loons were alleging?

[djellison]

That the feature about 75% across, 30% down was artificial

Stop laughing.

I explained that the CCD pixels were non square so a small feature could appear stretched after processing. I explained that deconvolution would artificilaly enhance features like that....and I showed the orig raw imagery and the re-sized imagery, yadda yadda yadda - but you know what these loonies are like, once they latch onto something...


I say debate...they proposed a quite rediculous theory - I counter it with evidence - they ignore the evidence and carry on. It's totally futile to be honest, but it's good 'sport' if nothing else

To give you an idea - the same person suggested that there are hangers on the moon, glass worms on mars, that he KNOWS Mars had a civilization in the past etc etc etc...

Doug

[Bob Shaw]

Doug:

Please don't go into *too* much detail, or else Google will lead the sods here! It's one thing having a gentlemanly discourse regarding impact vs uplift as the origin of the Columbia Hills (even if it sometimes degenerates into discussions of the geology of Benny Hill, the Phil Monty, et al) but if the green ink brigade start haunting our discussions we'll pass from the highly speculative to the merely laxative...

Bob Shaw

[ElkGroveDan]

To give you an idea - the same person suggested that there are hangers on the moon, glass worms on mars, that he KNOWS Mars had a civilization in the past etc etc etc...

OK I jumped on my Web Surfboard (they call me the Big Kahuna) and went looking for your debate, and found it. You're right. Those folks are what we call "whackjobs" in my business.

I will admit though that it does look a bit like an Imperial Walker from Star Wars

[djellison]

Oh - Bob - have no fear - I have a special administrating/moderating hat just for net kooks It comes with a large bat marked "ban"

They all know about this place but they've never come in here....because they know their arguments would be smashed to pieces.

Doug

[ljk4-1]

Near Earth Asteroid Rendezvous Guide

http://near.jhuapl.edu/media/NEARoverview.pdf

[Guest_AlexBlackwell_*]

Near Earth Asteroid Rendezvous Guide

http://near.jhuapl.edu/media/NEARoverview.pdf

I'm just curious: Is there any particular reason that you're reviving a thread that's been dormant for nearly a year by posting a bare link to a document that's nearly ten years old?