Rosetta flyby of Asteroid Steins, 5th September 2008 |
Rosetta flyby of Asteroid Steins, 5th September 2008 |
Sep 6 2008, 07:20 PM
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#181
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Junior Member Group: Members Posts: 47 Joined: 27-June 08 From: Ashford, Kent, United Kingdom. Member No.: 4244 |
Well, we still have the 2009 Earth Flyby to look forward to, and, more importantly, the July 2010 Lutetia flyby. With a 100 km diameter, it should be quite spectacular. Yes indeed Ted, & also will be the first ever Type M seen up in close quarters. If Rosetta repeats at 21 Lutetia, what happened last night, with the NAC not going into safing @ 2867 Steins then yes, it will be a major spectacle. Also a few images I have been working on. 2867 Steins, just before CA. 2867 Steins, just after CA. 2867 Steins crater chain. Andrew Brown. -------------------- "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.
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Sep 6 2008, 07:53 PM
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#182
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Member Group: Members Posts: 706 Joined: 22-April 05 Member No.: 351 |
Here's the first frame in the movie, with a contrast-enhanced version. [attachment=15567:first_fr...enhanced.jpg] All our pre-encounter guesses as to shape were way off (especially my 'snoopy' ). Who would have guess a diamond? Anyone want to hazard a carat calculation? -------------------- |
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Sep 6 2008, 07:57 PM
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#183
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Member Group: Members Posts: 706 Joined: 22-April 05 Member No.: 351 |
[attachment=15571:vesta.jpg] Emily - If you're up to it, an expansion of this with the best Ceres and Vesta images to date (and perhaps with a round place holder for 21 Lutetia) would be wonderful! -------------------- |
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Sep 6 2008, 08:19 PM
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#184
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Special Cookie Group: Members Posts: 2168 Joined: 6-April 05 From: Sintra | Portugal Member No.: 228 |
it'll be timed perfectly to start watching qualifying for the Belgium Grand Prix Yeah...do so...I'm heading this direction in an hour or so... -------------------- "Ride, boldly ride," The shade replied, "If you seek for Eldorado!"
Edgar Alan Poe |
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Sep 6 2008, 08:33 PM
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#185
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Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
Emily - If you're up to it, an expansion of this with the best Ceres and Vesta images to date (and perhaps with a round place holder for 21 Lutetia) would be wonderful! I think I'll wait on that for better data on Vesta and Ceres. In the meantime, you can see the current status of a related project I'm working on, to look at scales of stuff in the solar system, starting here: http://planetary.org/explore/topics/compar...le_1000000.html It's far from complete, has various formatting issues, and breaks down toward the end. Also I notice that my Prometheus image seems to be mis-scaled. But it seems appropriate to post it in this thread anyway. --Emily -------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
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Sep 6 2008, 08:50 PM
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#186
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Member Group: Members Posts: 370 Joined: 12-September 05 From: France Member No.: 495 |
Very nice project Emily !
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Sep 6 2008, 09:07 PM
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#187
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Junior Member Group: Members Posts: 59 Joined: 25-December 05 From: Stevens Point, Wisconsin, USA Member No.: 619 |
From a botanical perspective, Steins looks like a giant paradise or sapucia nut (Lethycis ollaria
a.k.a. “monkey pot”) in the Brazilnut family: http://www.jb.ul.pt/expo/images/im6.jpg |
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Sep 6 2008, 10:45 PM
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#188
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Senior Member Group: Members Posts: 2530 Joined: 20-April 05 Member No.: 321 |
Trouble will come with Lutecia's fly by! You'll have to change your scale... I think one of the central truths, one of the first we learn, in the study of outer space is that spatial scales differ from our everyday world by running across many more orders of magnitude than we can visualize. A tabletop model of the solar system would make the planets so small that virtually no one would even consider building such a thing without using different scales for the distances and the diameters of objects. Consider that if the Sun and Alpha Centauri were the sizes of basketballs, a scale model would have to place one in New York and the other in Beijing. When I made a screensaver of many solar system worlds for my son, I used the fourth power of diameter to convey the idea that some are bigger than others, but keep the smaller ones from being invisibly small. Whenever I hear a simple count of how many satellites one of the giants planet has, I tune out, it seems so irrelevant to count some of them equal to Ganymede. The fascinating thing with this comparative asteroidology is how they appear at different scales. Itokawa obviously has a texture we'll never see on something the size of Eros, much less Ceres. |
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Sep 6 2008, 11:23 PM
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#189
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Member Group: Members Posts: 809 Joined: 11-March 04 Member No.: 56 |
I think I'll wait on that for better data on Vesta and Ceres. In the meantime, you can see the current status of a related project I'm working on, to look at scales of stuff in the solar system, starting here: Oooh. That's really nice. I wish I'd had that when I started doing scale comparisons of the Solar System years ago. (Of course, a lot of those images didn't exist then.) At the round/not round boundary, for objects below Ceres in size, looking at those pictures made me change the questions I had been asking. I had been inclined to wonder: "Why are Vesta and Proteus so irregular, despite being so large?" But the images made me think instead: "Why are Enceladus and (to some extent) Mimas so round, despite being so small?" In the case of Enceladus I suppose it's tidal flexing combined with a high water-ice content, and continued resurfacing. |
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Sep 7 2008, 08:07 AM
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#190
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Special Cookie Group: Members Posts: 2168 Joined: 6-April 05 From: Sintra | Portugal Member No.: 228 |
In the meantime, you can see the current status of a related project I'm working on Nice... No room for Pluto?... -------------------- "Ride, boldly ride," The shade replied, "If you seek for Eldorado!"
Edgar Alan Poe |
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Guest_jumpjack_* |
Sep 7 2008, 01:43 PM
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#191
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OK, somebody has to do it and it might as well be me. [attachment=15564:Steins.wmv] Shoot me if you like Doug Congratulations, that's a REALLY cool movie! The music is absolutely appropriate! Indeed, after looking at 3d anaglyph, this "rock" does not look at alla s adiamond, but more like... a spaceship! It's just an optical illusion if it looks like a diamond, due to complete darkness of the side not directly hit by sunlight. I imagine something like this: About the origin of craters, couldn't it be the same of Jupiter/ShoemakerLevy? Another hypotesys: could Sun have acted on the asteroid like on a comet, in case it contained some material which, due to high temperature, exploded, causing the crater?!? This would explain why the asteroid didn't get destroyed by an impact which created a crater large 40% of its size! (consider very low gravity of such a small body). |
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Sep 7 2008, 02:33 PM
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#192
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Member Group: Members Posts: 109 Joined: 20-January 07 From: Milano, ITALY Member No.: 1633 |
About the origin of craters, couldn't it be the same of Jupiter/ShoemakerLevy? Bad Astronomer Phil Plait also thinks so. Paolo Amoroso -------------------- Avventure Planetarie - Blog sulla comunicazione e divulgazione scientifica
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Sep 7 2008, 03:49 PM
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#193
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Member Group: Members Posts: 128 Joined: 10-December 06 From: Atlanta Member No.: 1472 |
The problem with this hypothesis is that Steins does not have enough gravity to break-up an impactor. In means some other object had broken the impactor first (the prime suspect is, of course, Jupiter). But I guess the broken fragments would not retain their linear formation for long (anyone known how long?). In its current orbit, Steins is nowhere close to Jupiter (it orbits between 2.0 to 2.7 AU). So, either it was in the vicinity of the Jupiter long time ago or the impactor passed through the Jupiter system, got broken up and then headed straight for Steins >3 AU away (which is possible, but I like a hypothesis with less chance element in it). |
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Sep 7 2008, 04:48 PM
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#194
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Senior Member Group: Moderator Posts: 3233 Joined: 11-February 04 From: Tucson, AZ Member No.: 23 |
Well, I seriously doubt that's a secondary crater chain, and as far as a chain of impacts from a broken-up impactor... possible, but I doubt it. What if these are pits created by regolith collapsing into a large fracture caused by the large impacts on Steins, akin to the pit chains you see on Mars at lava tubes?
-------------------- &@^^!% Jim! I'm a geologist, not a physicist!
The Gish Bar Times - A Blog all about Jupiter's Moon Io |
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Sep 7 2008, 05:05 PM
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#195
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Member Group: Members Posts: 128 Joined: 10-December 06 From: Atlanta Member No.: 1472 |
What if these are pits created by regolith collapsing into a large fracture caused by the large impacts on Steins, akin to the pit chains you see on Mars at lava tubes? I wish higher resolution images were available. The morphology of the craters (e.g. presence of a central peak, shape...) would have been really helpful to tell a lava pit from an impact crater. |
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