Dawn's first orbit, including RC3, March 6, 2015- June 15, 2015 |
Dawn's first orbit, including RC3, March 6, 2015- June 15, 2015 |
Mar 6 2015, 03:23 PM
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#1
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Member Group: Members Posts: 204 Joined: 14-April 06 From: Seattle, WA Member No.: 745 |
Dawn is now officially in orbit around (1) Ceres!
Congratulations, NASA. Nice images of crescent Ceres. NASA Spacecraft Becomes First to Orbit a Dwarf Planet |
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Mar 6 2015, 04:29 PM
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#2
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Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
I thought it was time for a new thread, now that Dawn's in its first orbit. We can look forward to a couple more op navs, on April 10 and 14, and then RC3 later in the month. Use the previous thread for up to Op Nav 5; let's use this thread for Op Navs 6 and 7 and RC3 and then we'll split again once Dawn reaches its first survey orbit.
-------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
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Mar 7 2015, 12:01 AM
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#3
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Member Group: Members Posts: 207 Joined: 6-March 07 From: houston, texas Member No.: 1828 |
I thought it was time for a new thread, now that Dawn's in its first orbit. We can look forward to a couple more op navs, on April 10 and 14, and then RC3 later in the month. Use the previous thread for up to Op Nav 5; let's use this thread for Op Navs 6 and 7 and RC3 and then we'll split again once Dawn reaches its first survey orbit. thanks emily! i noticed in a prior thread that it said mapping starts in July. thats a bit of a misnomer as mapping starts in Survey Orbit in May (and one can count RC3 as a global map, at about 1.5 km resolution, which is comparable to much of Voyager at Saturn.) wows! -------------------- Dr. Paul Schenk, Lunar and Planetary Institute, Houston TX
http://stereomoons.blogspot.com; http://www.youtube.com/galsat400; http://www.lpi.usra.edu/science/schenk/ |
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Mar 7 2015, 09:28 AM
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#4
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Member Group: Members Posts: 423 Joined: 13-November 14 From: Norway Member No.: 7310 |
What should nonetheless be correct is that a new mapping phase starts in July, namely HAMO; and that this is still the month New Horizon zooms past Pluto.
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Mar 8 2015, 12:36 AM
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#5
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Member Group: Members Posts: 153 Joined: 20-December 14 From: Eastbourne, UK Member No.: 7372 |
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Mar 8 2015, 04:29 AM
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#6
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Junior Member Group: Members Posts: 59 Joined: 4-July 08 Member No.: 4251 |
From http://www.nasa.gov/press/2015/march/nasa-...ly-enter-orbit/ :
QUOTE NASA will host a media teleconference at 2 p.m. EST today [Friday] to discuss the historic arrival of the agency’s Dawn spacecraft at the dwarf planet Ceres. ... Participants in the teleconference will be: - Jim Green, director, Planetary Science Division, NASA Headquarters, Washington - Carol Raymond, Dawn mission deputy principal investigator, Jet Propulsion Laboratory, Pasadena, California The teleconference will be streamed live on NASA’s website, at: http://www.nasa.gov/newsaudio Does anyone know if a recording of this telecon exists? Normally, at the end of a NASA telecon they offer a number that you can call into to hear it again -- inexplicably, they only offer that number DURING the call itself. Also, JPL will sometimes take the audio and make a video out of it (synced with slides if there are any) and upload to the Ustream or Youtube account. Or was there absolutely nothing of interest said during the telecon, just the usual recapping of what's happened? Thanks! |
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Mar 8 2015, 02:27 PM
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#7
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Senior Member Group: Members Posts: 2346 Joined: 7-December 12 Member No.: 6780 |
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Mar 8 2015, 08:49 PM
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#8
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Junior Member Group: Members Posts: 59 Joined: 4-July 08 Member No.: 4251 |
Thanks but that's the PREVIEW briefing, that aired on NASA TV on Monday. I'm talking about the teleconference (media phone call) from Friday. |
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Mar 9 2015, 03:58 PM
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#9
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Member Group: Members Posts: 201 Joined: 16-December 13 Member No.: 7067 |
Searched for it on YouTube:
https://www.youtube.com/watch?v=Qk0Cr0Z13hc Edit: finally had a chance to listen to it - nothing new was said, really. |
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Mar 9 2015, 11:03 PM
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#10
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Member Group: Members Posts: 495 Joined: 12-February 12 Member No.: 6336 |
Also the time when the fireworks on 67P are expected to really start. And Voyager 2 might break out into interstellar space at about the same time also. The values for the interstellar >70 MeV protons have been slowly climbing to the same value as for V2 - though if the current trend holds it might happen a few months later. |
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Mar 10 2015, 02:32 AM
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#11
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Junior Member Group: Members Posts: 59 Joined: 4-July 08 Member No.: 4251 |
Searched for it on YouTube: https://www.youtube.com/watch?v=Qk0Cr0Z13hc Edit: finally had a chance to listen to it - nothing new was said, really. THANK YOU!!! |
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Mar 11 2015, 01:53 PM
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#12
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Member Group: Members Posts: 568 Joined: 20-April 05 From: Silesia Member No.: 299 |
-------------------- Free software for planetary science (including Cassini Image Viewer).
http://members.tripod.com/petermasek/marinerall.html |
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Mar 11 2015, 03:48 PM
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#13
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Junior Member Group: Members Posts: 61 Joined: 20-March 10 From: Western Australia Member No.: 5275 |
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Mar 12 2015, 02:44 AM
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#14
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Member Group: Members Posts: 715 Joined: 3-January 08 Member No.: 3995 |
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Mar 12 2015, 08:02 AM
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#15
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Member Group: Members Posts: 401 Joined: 5-January 07 From: Manchester England Member No.: 1563 |
Oh my, talk about making the familiar unusual.... -------------------- |
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Mar 12 2015, 10:08 AM
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#16
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Member Group: Members Posts: 241 Joined: 22-August 05 From: Stockholm Sweden Member No.: 468 |
I like these perspective jolting moments. My absolute favorite is earth and the moon seen from mercury during the lunar eclipse.
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Apr 15 2015, 11:12 AM
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#17
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Member Group: Members Posts: 423 Joined: 13-November 14 From: Norway Member No.: 7310 |
Dawn is currently communicating with Earth. Here's hoping for some of spot(s) 5.
http://eyes.nasa.gov/dsn/dsn.html -------------------- |
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Apr 16 2015, 04:53 AM
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#18
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Member Group: Members Posts: 890 Joined: 18-November 08 Member No.: 4489 |
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Apr 16 2015, 07:09 PM
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#19
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Member Group: Members Posts: 813 Joined: 29-December 05 From: NE Oh, USA Member No.: 627 |
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Apr 16 2015, 07:11 PM
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#20
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Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
JPL has released an animation of the April 10 opnavs. Very cool
On Twitter, Brian Wolven asked me if the prominent bright peaks seen at the right-hand limb at the beginning of the animation were the two bright spots. I tried to figure out the answer to that, but couldn't. I made the attached polar projection of the northern hemisphere of the DEM from JohnVV's map, but I couldn't match crater features. -------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
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Apr 16 2015, 07:31 PM
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#21
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Member Group: Members Posts: 890 Joined: 18-November 08 Member No.: 4489 |
it would NOT be visible YET in the April 10 images
it is at 20 deg North what is visible in that gif is 50+ to 90 north as you can see in these two screenshots ( if the naif kernels are accurate, i have been having MAJOR issues with some of them ) added extra light to the scene -- FOR APRIL 10 like the gif-- near the center - off to the right side of ceres |
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Apr 16 2015, 07:36 PM
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#22
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Member Group: Members Posts: 423 Joined: 13-November 14 From: Norway Member No.: 7310 |
Pleasantly surprised to see that OpNav 6 was released today. Something odd happens when I try to extract the individual frames with IrfanView, though: the frames come out in all sorts of sizes. (edit: never mind, Python to the rescue)
In the latest Dawn Journal, it was mentioned that spot(s) 5 would not be visible in OpNav 6: QUOTE As we describe below, Dawn’s extensive photographic coverage of the sunlit terrain in early May will include these bright spots. They will not be in view, however, when Dawn spies the thin crescent of Ceres in its next optical navigation session, scheduled for April 10 so I think it would be odd if they suddenly turned up anyway. -------------------- |
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Apr 16 2015, 07:37 PM
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#23
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Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
it would NOT be visible YET Thanks for those simulations, they are really helpful. -------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
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Apr 16 2015, 08:12 PM
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#24
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Member Group: Members Posts: 890 Joined: 18-November 08 Member No.: 4489 |
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Apr 16 2015, 09:18 PM
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#25
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Member Group: Members Posts: 715 Joined: 3-January 08 Member No.: 3995 |
I think this mound (or mounds) in the large crater is a good candidate for the limb peaks:
Note the trio of craters circled in red: They seem to correspond with the craters in red here: Now extend a longitudinal line over the north pole here: And here (north pole marked with 'N'): The peaks are to the east of the line. The crater with the mound(s) is marked with a yellow box on the longitudinal map. |
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Apr 17 2015, 04:14 AM
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#26
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Senior Member Group: Members Posts: 2346 Joined: 7-December 12 Member No.: 6780 |
With the following assumed globes for PIA19317.gif OpNav6
I've obtained these projections: Addition of the projections to the DLR map from RC2: The bright spot is probably just outside frame 20 of the sequence. |
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Apr 17 2015, 05:56 AM
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#27
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Member Group: Members Posts: 890 Joined: 18-November 08 Member No.: 4489 |
aligning the animated gif with the textured mesh and lat long marks
the other "bright spot" is at 42 N and 0 long. it is barely visible in the gif 3 frames from the gif with and without a spherical grid the 0/360 long is top right on the sphere and you can see the major bright spot hidden under the horizon almost visible on the top left |
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Apr 17 2015, 08:20 AM
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#28
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Member Group: Members Posts: 648 Joined: 9-May 05 From: Subotica Member No.: 384 |
Ceres rotating back and forth in latest images from Dawn spacecraft.
I find it much easier to spot different surface details this way. -------------------- The scientist does not study nature because it is useful; he studies it because he delights in it, and he delights in it because it is beautiful.
Jules H. Poincare My "Astrophotos" gallery on flickr... |
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Apr 17 2015, 10:44 AM
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#29
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Member Group: Members Posts: 495 Joined: 12-February 12 Member No.: 6336 |
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Apr 17 2015, 05:26 PM
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#30
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Member Group: Members Posts: 107 Joined: 1-August 14 Member No.: 7227 |
Ceres rotating back and forth in latest images from Dawn spacecraft. I find it much easier to spot different surface details this way. I can't figure out if bright spot is visible in the animation. I place here the other available images for more comfortable comparisons: http://cdn.phys.org/newman/csz/news/800/20...warfplanetc.jpg http://cdn.phys.org/newman/csz/news/800/20...hisimageist.jpg https://lightsinthedark.files.wordpress.com...3/pia189231.jpg http://www.jpl.nasa.gov/spaceimages/images...19056_hires.jpg I don't understand if I must link them or upload them or insert them in tag so I just add the links. |
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Apr 17 2015, 06:01 PM
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#31
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Founder Group: Chairman Posts: 14433 Joined: 8-February 04 Member No.: 1 |
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Apr 17 2015, 09:56 PM
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#32
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Member Group: Members Posts: 555 Joined: 27-September 10 Member No.: 5458 |
Im rather curious about these two spots that appear in frame 6 and frame 7. Not necessarily from spot 5 but in the same vicinity. They are somewhat dim and on the left lim.
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Apr 17 2015, 10:04 PM
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#33
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Member Group: Members Posts: 890 Joined: 18-November 08 Member No.: 4489 |
ZLD - your map is upside down
That is the two side by side spots that are at 20 degrees NORTH and 240 degrees longitude and is visible in the added light 3d graphic I posted here of the two recreations that show where it WOULD be IF it was lite http://www.unmannedspaceflight.com/index.p...st&p=219593 you can see in the first image ( added extra AMBIENT light ) to the 3d rendering |
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Apr 17 2015, 10:39 PM
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#34
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Member Group: Members Posts: 715 Joined: 3-January 08 Member No.: 3995 |
JohnVV, thanks much for the simulations with the grids. They really help to put things into perspective.
Also, have you yet added the grid to the global cylindrical map? |
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Apr 17 2015, 10:51 PM
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#35
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Member Group: Members Posts: 890 Joined: 18-November 08 Member No.: 4489 |
the grid is dynamically added in the 3d program i am using .
Ceres's orbit is calculated using the JPL orbit data and Dawn's orbit is also calculated using it's orbital data the same data that the research scientists are using the naif kernels. As to the map. The map posted is 0 long to 360 long ( 180 in the center ) a grid could be added ? but not really needed this very EARLY map is very low resolution 1024x512 pixels and the poles ARE MISSING. In comparison the published Vesta map is 48 ppd ( 17,280 X 8,641 ) pixels . |
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Apr 20 2015, 01:59 PM
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#36
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Member Group: Members Posts: 423 Joined: 13-November 14 From: Norway Member No.: 7310 |
Is the dimmest bright spot resolved in the OpNav 7 images? It looks distinctly elongated in all frames where it "glows":
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Apr 20 2015, 02:18 PM
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#37
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Founder Group: Chairman Posts: 14433 Joined: 8-February 04 Member No.: 1 |
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Apr 20 2015, 03:15 PM
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#38
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Member Group: Members Posts: 423 Joined: 13-November 14 From: Norway Member No.: 7310 |
I don't see how that implies that they are resolved.
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Apr 20 2015, 03:17 PM
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#39
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Senior Member Group: Members Posts: 2173 Joined: 28-December 04 From: Florida, USA Member No.: 132 |
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Apr 20 2015, 03:24 PM
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#40
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Member Group: Members Posts: 423 Joined: 13-November 14 From: Norway Member No.: 7310 |
Just noting that it looks like it spans more than one pixel at this resolution (and also that it looks elongated from this vantage point). Looking a bit more closely at the images, it seems almost certain to me that it is resolved; but I haven't seen any relevant comments from the science team.
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Apr 20 2015, 04:40 PM
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#41
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Member Group: Members Posts: 890 Joined: 18-November 08 Member No.: 4489 |
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Apr 20 2015, 04:50 PM
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#42
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Newbie Group: Members Posts: 2 Joined: 11-March 15 Member No.: 7412 |
The surface between the craters looks very smooth. The smooth areas between craters may only appear that way because of smaller craters can't be seen due to the low resolution of the current set of images. But, so far, there does not appear to be mountains or ridges between the craters.
Also, when I imagine a generic crater, say on the moon, I think of the surrounding of it sloping up fairly steeply then the surface dropping sharply as you go into the crater. But I don't see much of a rise on the outside edges of the craters. Are these craters really that smooth or does it look like that because the resolution or sun angle in these images? If they are really that slightly sloped on the outside, could it be because of what might be below the surface or -------------------- In satellite operations, schedules are governed by the laws of physics and bounded by the limits of technology.
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Apr 20 2015, 05:15 PM
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#43
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Member Group: Members Posts: 890 Joined: 18-November 08 Member No.: 4489 |
do to the fact that Ceres is very high in ices the craters have flat bottoms and are shallow
the one in the crops i posted looks to be on one of the ridges and came in at a very shallow angle some of the "smoothness "is do to the 4x enlargement and that the original crop was only 128 px on a side ( rather small) keep in mind that the spacecraft is NOT YET even in a near circular orbit YET and this set of images is from April 14/15 -- LAST WEEK |
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Apr 20 2015, 06:02 PM
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#44
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Member Group: Members Posts: 495 Joined: 12-February 12 Member No.: 6336 |
Looking a bit more closely at the images, it seems almost certain to me that it is resolved; but I haven't seen any relevant comments from the science team. Yes I tend to agree thinking its resolved or nearly so on the first image of the sequence, but on the subsequent images it seem to get saturated and float into adjacent pixel areas -and so larger than it actually is -again Edit: It's not the first, but frames 8 and 9, the page loaded to slow so I missed the early part of the rotation sequence, but I did separate the images after the post to find out. |
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Apr 20 2015, 06:06 PM
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#45
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Member Group: Members Posts: 648 Joined: 9-May 05 From: Subotica Member No.: 384 |
Back and forth animation made using grabbed frames from 20 frame gif.
All 20 frames separated into .png images on Dropbox. -------------------- The scientist does not study nature because it is useful; he studies it because he delights in it, and he delights in it because it is beautiful.
Jules H. Poincare My "Astrophotos" gallery on flickr... |
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Apr 20 2015, 06:10 PM
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#46
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Senior Member Group: Members Posts: 1643 Joined: 5-March 05 From: Boulder, CO Member No.: 184 |
Yes I tend to agree thinking its resolved or nearly so on the first image of the sequence, but on the subsequent images it seem to get saturated and float into adjacent pixel areas -and so larger than it actually is -again The linear arrangement almost has the look of the "Voyager Mountains" on Iapetus... -------------------- Steve [ my home page and planetary maps page ]
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Apr 20 2015, 09:27 PM
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#47
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Member Group: Members Posts: 555 Joined: 27-September 10 Member No.: 5458 |
Performed some slight enhancements on frame 10 of the PIA19064 animation. Cropped, luminance adjustment, deconvolution and scaled 200%.
And again with frame 11. These are stretched until the bright region is slightly below max saturation. -------------------- |
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Apr 20 2015, 10:55 PM
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#48
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Member Group: Members Posts: 715 Joined: 3-January 08 Member No.: 3995 |
The bright spot seems to be less prominent when on the morning terminator than on the evening. One possibility is that much of the bright material is on a west-facing slope.
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Apr 21 2015, 02:00 AM
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#49
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Junior Member Group: Members Posts: 68 Joined: 27-March 15 Member No.: 7426 |
Dr. Chris Russell, principal investigator of the Dawn mission, indicated in an e mail today to NBC News that even at the current resolution (
NBC News Article |
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Apr 21 2015, 03:48 AM
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#50
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Senior Member Group: Members Posts: 2090 Joined: 13-February 10 From: Ontario Member No.: 5221 |
The fact that these things were visible from Earth still blows my mind. How small would they have to be before we get in the range of an Enceladean albedo?
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Apr 21 2015, 11:14 AM
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#51
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Senior Member Group: Members Posts: 2346 Joined: 7-December 12 Member No.: 6780 |
Assuming the globes
here a forward/back animation (1200 pixels) of rectangular roughly map-projected versions of the 20-frames OpNav7 sequence PIA19064.gif, aligned to the DLR RC2 map: (NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/"Gerald") Album of individual projected frames (1440x720 pixels). |
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Apr 21 2015, 02:11 PM
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#52
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Junior Member Group: Members Posts: 68 Joined: 27-March 15 Member No.: 7426 |
The fact that these things were visible from Earth still blows my mind. How small would they have to be before we get in the range of an Enceladean albedo? Well, it appears that the ratio of an area 3.7 kilometers in diameter to one that is 1.3 km across is about 8.1 to 1. I'm assuming that albedo is inversely proportional to reflective area. If I'm not mistaken, one could multiply the old albedo figure of 0.4 by the 8.1 ratio to get the minimum new albedo. |
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Apr 21 2015, 03:25 PM
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#53
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Senior Member Group: Members Posts: 2346 Joined: 7-December 12 Member No.: 6780 |
Albedos greater than 1.0 are very rare in nature.
... Forth-back animation of polar projections of OpNav7 (same globes assumed as above) : Album of individual 1440px maps. |
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Apr 21 2015, 03:32 PM
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#54
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Member Group: Members Posts: 112 Joined: 31-January 15 From: Houston, TX USA Member No.: 7390 |
The bright spot seems to be less prominent when on the morning terminator than on the evening. One possibility is that much of the bright material is on a west-facing slope. If this were a geologically recent active region, wouldn't a reasonable expectation be that the crater floor is smooth as the material flows or falls onto the floor? It's hard to tell whether the crater floor in the zoomed-in version is itself cratered or those are image processing artifacts. My money is still on a shallow angle impact causing the center bright spot with a secondary impact causing the second spot. It also explains the variability in brightness between different viewing angles. Andy |
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Apr 21 2015, 03:37 PM
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#55
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Senior Member Group: Members Posts: 4251 Joined: 17-January 05 Member No.: 152 |
Dr. Chris Russell, principal investigator of the Dawn mission, indicated in an e mail today to NBC News that even at the current resolution (1300 meters/pixel) the bright spots were not resolved. It probably depends on exactly what you mean by "resolved". There's certainly not much detail visible in both of the two spot 5 subspots, but I would call them "resolved" in the sense that they are clearly larger than the PSF. Both of the subspots are elongated, and the orienation of elongation rotates with Ceres. This means the elongation can't be due to bad optics (eg, astigmatism) and almost certainly not due to motion blur during the exposure. Similarly, it is extremely unlikely for pixel noise to conspire to produce elongation in both subspots rotating consistently with Ceres's rotation, even though we're looking at only a small number of pixels here (ie, S/N looks good judging from frame-to-frame consistency).It appears that the fainter subspot (upper in my animation below) is composed of two "sub-subspots" (again, the consistency from frame to frame argues against pixel noise). The brightest subspot (lower in my animation) perhaps also consists of two sub-subspots, the lower of which appears first and the upper which brightens. As others have pointed out, these sorts of brightness variations could be simply due to variable geometry of exposed surfaces/shadowing. |
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Apr 21 2015, 03:48 PM
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#56
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Senior Member Group: Members Posts: 2346 Joined: 7-December 12 Member No.: 6780 |
I'd assign the apparent split of the fainter spot to a more or less concentrical topographical feature in the crater. So it's not necessarily an albedo feature, but possibly an "inclination" feature.
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Apr 21 2015, 04:55 PM
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#57
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Senior Member Group: Members Posts: 4251 Joined: 17-January 05 Member No.: 152 |
But the upper double spot only brightens as you go from frame to frame. If the dark gap between the two sub-subspots was due to inclination, the dark gap should have been more prominent in the earlier frames when the illumination angle was lower.
Of course the real problem is that we're arguing over only a few pixels here. One way to improve things while we wait is to note that the spot 5 crater remains at roughly the same distance from the limb in all the frames, ie we're roughly "looking straight down at the north pole". So the viewing geometry for the crater is roughly constant. So someone could usefully do a poor-man's superresolution by enlarging (say 4x), rotating, and then stacking the images... |
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Apr 21 2015, 06:25 PM
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#58
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Junior Member Group: Members Posts: 68 Joined: 27-March 15 Member No.: 7426 |
It probably depends on exactly what you mean by "resolved". There's certainly not much detail visible in both of the two spot 5 subspots, but I would call them "resolved" in the sense that they are clearly larger than the PSF. I recall when only one bright spot was discernible in this crater, then there were two. There was apparently no claim that the spot had been optically resolved at this point. When Dr. Russell says that the spots are not resolved because they're too small, I'm inclined to rely on that, given his expertise, and knowledge of this particular situation. It does not appear to me that the brighter of the two spots is even separated into two distinct parts, which seems to argue against any reasonable definition of the word 'resolved'. The variable lighting of portions of this spot could have any one of several explanations. The bright spot sometimes appeared to be elongated in the images, long before there was any thought that it might be optically resolved. ADMIN NOTE: Everyone - I think that we can drop the discussion over the word 'resolved'. You can go into the 'micron' scale and still not fully "resolve" an object. Let's just wait for better images that will help to identify the nature of these features. Not long now. |
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Apr 21 2015, 06:34 PM
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#59
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Member Group: Members Posts: 890 Joined: 18-November 08 Member No.: 4489 |
QUOTE The bright spot seems to be less prominent when on the morning terminator than on the evening. One possibility is that much of the bright material is on a west-facing slope. as one can see in the second attached image in post # 41 it is on a west facing slope as to the other one WE WELL SEE --- once there are better images |
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Apr 21 2015, 07:00 PM
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#60
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Senior Member Group: Members Posts: 3419 Joined: 9-February 04 From: Minneapolis, MN, USA Member No.: 15 |
In the previous image, and also in the animations showing this region, I'm tempted to say that it's not ejecta that's so bright. This "spot" is resolved to the point that, when not saturating the ccd's, it looks like a pyramidal structure (in shape, not at all suggesting it was artificially constructed) that is definitely lighter in color than the surrounding terrain. It doesn't exactly follow the curves of the crater wall it seems to overly, either.
I'm wondering if this could be a constructional landform -- looks a little like a volcano-like structure in this image, at any rate. Boy, it'll be nice to get better pictures of these areas. Patience... I must learn patience... -the other Doug -------------------- “The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
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Apr 21 2015, 07:52 PM
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#61
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Junior Member Group: Members Posts: 98 Joined: 30-November 05 From: Antibes, France Member No.: 594 |
The linear arrangement almost has the look of the "Voyager Mountains" on Iapetus... Well found for the analogy Scalbers! I've extracted a portion of the Voyager Moutains and the bright patch of Iapetus, about 5 km long, looks like the bright spot of Ceres... to a certain extent!
Attached image(s)
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Apr 21 2015, 08:07 PM
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#62
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Member Group: Members Posts: 715 Joined: 3-January 08 Member No.: 3995 |
The brightest subspot (lower in my animation) perhaps also consists of two sub-subspots, the lower of which appears first and the upper which brightens. As others have pointed out, these sorts of brightness variations could be simply due to variable geometry of exposed surfaces/shadowing. That animation really helps. I'm seeing (imagining) something along these lines: The main bright area seems to be in the western part of a little depression of some kind, with the brightest material not becoming visible until the shadow clears the slope. (Nothing in the drawing is necessarily to scale; plus, I intentionally left out the other bright spot(s).) |
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Apr 21 2015, 09:10 PM
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#63
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Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
-------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
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Apr 21 2015, 09:20 PM
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#64
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Junior Member Group: Members Posts: 48 Joined: 20-December 14 Member No.: 7370 |
A heavily zoomed and exposure enhanced version of the first 3 frames of the bright spot. (this may have introduced artifacts - but overall it allows a better overall visualization IMHO)
I think the these frames clearly show the outline of a crater with the far wall getting the first bit of sunlight. As the sun rises in the crater the crater gets more and more illuminated causing pixel saturation and bleed for the subsequent not shown images, but roughly corresponding to the crater dimensions. [click to animate the GIF] |
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Apr 21 2015, 10:16 PM
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#65
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Member Group: Members Posts: 555 Joined: 27-September 10 Member No.: 5458 |
Is there any speculation on what would be able to leave such a smooth, shiny depression? To me, it appears that much of the crater may be a similar make up because as the sun angle decreases, the crater continues to light up. Seems to be smack dab in the middle as well. Possibly a remnant of some cryo-gyser sort of blow out maybe?
-------------------- |
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Apr 21 2015, 10:24 PM
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#66
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Member Group: Members Posts: 890 Joined: 18-November 08 Member No.: 4489 |
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Apr 21 2015, 10:50 PM
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#67
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Senior Member Group: Members Posts: 2346 Joined: 7-December 12 Member No.: 6780 |
...So someone could usefully do a poor-man's superresolution by enlarging (say 4x), rotating, and then stacking the images... PIA19064, 4x magnified (probably bicubic), then polar-projected (bilinear interpolated) to 2880x2880 pixels, then cropped and registered, then pairwise averaged (stacked), sharpened, forth/back animated: |
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Apr 21 2015, 11:05 PM
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#68
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Member Group: Members Posts: 715 Joined: 3-January 08 Member No.: 3995 |
Is anyone else having issues with the released animated GIF not repeating/looping?
( http://dawn.jpl.nasa.gov/news/Ceres_bright...k_into_view.asp ) |
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Apr 21 2015, 11:15 PM
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#69
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Senior Member Group: Members Posts: 2346 Joined: 7-December 12 Member No.: 6780 |
Yes, with (outdated) Windows XP / Chrome, at least.
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Apr 22 2015, 01:43 AM
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#70
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Senior Member Group: Members Posts: 2430 Joined: 30-January 13 From: Penang, Malaysia. Member No.: 6853 |
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Apr 22 2015, 02:26 AM
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#71
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Member Group: Members Posts: 890 Joined: 18-November 08 Member No.: 4489 |
it is a setting ON!!! the dawn web site !
THEY!!! have the gif set to "run once" |
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Apr 22 2015, 03:06 AM
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#72
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Merciless Robot Group: Admin Posts: 8784 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
Yeah, must be. I had to clear my cache to get it to run again. Hopefully this will be noticed and corrected soon; meanwhile, let's all be patient.
-------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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Apr 22 2015, 03:48 AM
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#73
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Senior Member Group: Members Posts: 4251 Joined: 17-January 05 Member No.: 152 |
Works fine (even on ancient xp) if you download the gif and play in, eg, irfanview.
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Apr 22 2015, 04:14 AM
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#74
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Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
-------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
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Apr 22 2015, 12:41 PM
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#75
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Junior Member Group: Members Posts: 61 Joined: 20-March 10 From: Western Australia Member No.: 5275 |
Emily, great input. Like everyone here, hanging out for the hi resolution pics.
Anxiety level akin to Huygens. We may actually be seeing a steady `volcanic eruption`. |
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Apr 26 2015, 11:27 PM
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#76
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Junior Member Group: Members Posts: 68 Joined: 27-March 15 Member No.: 7426 |
It's said that when Dawn's mission is finished, they'll park it permanently in orbit of Ceres. A good thing they won't have to feed coins to De meter.
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Apr 27 2015, 01:17 AM
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#77
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Merciless Robot Group: Admin Posts: 8784 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
...aaaand, Dudley's banned.
-------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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Apr 27 2015, 12:45 PM
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#78
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Member Group: Members Posts: 723 Joined: 13-June 04 Member No.: 82 |
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Apr 27 2015, 02:06 PM
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#79
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Interplanetary Dumpster Diver Group: Admin Posts: 4404 Joined: 17-February 04 From: Powell, TN Member No.: 33 |
That was a joke, Ceres is the Roman equivalent of the Greek Demeter. Unless you were also making a joke about making puns on this thread. I guess the smiley was a clue. It is rather unforgivable -------------------- |
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Apr 27 2015, 02:59 PM
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#80
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Junior Member Group: Members Posts: 68 Joined: 27-March 15 Member No.: 7426 |
It's just that I feel it's important to get some pun out of life!
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Apr 29 2015, 02:28 PM
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#81
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Member Group: Members Posts: 541 Joined: 17-November 05 From: Oklahoma Member No.: 557 |
Looks like the Dawn website just underwent a major overhaul...
dawn.jpl.nasa.gov At first glance, I can't find where the "Where is Dawn now" simulated views have gone. |
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Apr 29 2015, 03:43 PM
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#82
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Newbie Group: Members Posts: 2 Joined: 11-March 15 Member No.: 7412 |
Yes. It looks like they've changed the user interface to be more tablet friendly, as many web sites are starting to do. Unfortunately, my primary web access (at work and at home) are desk tops, which aren't as user friendly as for these tablet friendly sites.
The "where is Dawn now" can be found by selecting the Menu button, then clicking (or tapping) on Mission. About a quarter of the way down the Mission page, you'll see "Where is Dawn now?" followed by a link labled "> View". Or you can just use this link here: http://dawn.jpl.nasa.gov/mission/live_shots.html -------------------- In satellite operations, schedules are governed by the laws of physics and bounded by the limits of technology.
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Apr 29 2015, 05:29 PM
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#83
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Member Group: Members Posts: 890 Joined: 18-November 08 Member No.: 4489 |
all this "portrait" formatting on LANDSCAPE 16X9 screens !!!
( a TON of sites are doing this so...) makes one REALLY WANT some of the by-gone days of what sites USED to look like CODE w3m http://dawn.jpl.nasa.gov/ nasa.gov 1996 http://web.archive.org/web/19961231235847/...//www.nasa.gov/ |
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Apr 29 2015, 05:52 PM
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#84
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Solar System Cartographer Group: Members Posts: 10184 Joined: 5-April 05 From: Canada Member No.: 227 |
I really don't like this new trend. It's a fad among web designers - like the one a year or two ago where everything on the screen would flash and shake as the cursor moved over it. The most basic principles of good design are being thrown out of the window, mainly because designers need to keep changing sites or they are out of a job.
If UMSF goes the same way I'm quitting! Or at least I would if there was anywhere else to go. Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke Maps for download (free PD: https://upload.wikimedia.org/wikipedia/comm...Cartography.pdf NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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Apr 29 2015, 06:26 PM
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#85
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Junior Member Group: Members Posts: 39 Joined: 9-August 12 From: London, UK Member No.: 6521 |
A shame we're reduced to discussing website design, interesting though it is. I too prefer pages rather than the scroll-for-ever sites of today.
Anyone have any idea when we might see the next images, presumably there are some great shots since getting into orbit that we're not seeing yet? |
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Apr 29 2015, 06:35 PM
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#86
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Founder Group: Chairman Posts: 14433 Joined: 8-February 04 Member No.: 1 |
The most basic principles of good design are being thrown out of the window, mainly because designers need to keep changing sites or they are out of a job. I can't stand this shift to 'trendy' websites either....but I have had visibility into the process behind the redesign for many of JPLs pages...and I can tell you, the demand for it isn't coming from designers, it's coming from management. And when it's winning awards all over the place - it's not going to go away any time soon : http://www.jpl.nasa.gov/news/news.php?feature=4566 |
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Apr 29 2015, 06:59 PM
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#87
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Member Group: Members Posts: 890 Joined: 18-November 08 Member No.: 4489 |
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Apr 29 2015, 07:31 PM
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#88
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Member Group: Members Posts: 423 Joined: 13-November 14 From: Norway Member No.: 7310 |
New RC3 image is out at the photojournal: http://photojournal.jpl.nasa.gov/catalog/PIA19319
Think it might show one of the interesting big craters near the south pole? -------------------- |
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Apr 29 2015, 08:46 PM
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#89
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Member Group: Members Posts: 423 Joined: 13-November 14 From: Norway Member No.: 7310 |
Following up on that image, is the relatively crater-free area above the crater in this crop part of a massive landslide? Have we observed something similar on other bodies?
The crater floor also appears to be of a relatively young age. -------------------- |
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Apr 29 2015, 08:56 PM
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#90
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Senior Member Group: Members Posts: 3419 Joined: 9-February 04 From: Minneapolis, MN, USA Member No.: 15 |
It looks more like a massive ejecta sheet to me, and we do see those commonly on our own Moon. They are most often seen, on the Moon, as ejecta from large basin impacts. As a comparison, take a look at the Fra Mauro formation on the Moon's near side.
In fact, this resembles that kind of structure quite a bit. -the other Doug -------------------- “The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
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Apr 29 2015, 09:32 PM
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#91
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Member Group: Members Posts: 715 Joined: 3-January 08 Member No.: 3995 |
Since we're on the subject of website design trends/fads, I'm not fond of the 'load more'- or 'fetch more images'-style of display. After awhile, the browser chokes and dies before all thumbnails, posts, etc. can be viewed. Two examples of this on well-known sites:
https://www.flickr.com/search/?q=ceres%20dawn https://instagram.com/marscuriosity/ I guess I'm old fashioned, but I don't mind having to click 'page 2' to see the next 50 image thumbnails. At least the image display formatting on the Dawn site is still 'old fashioned'. --------- Ok. Back on topic: That modified terrain around the large crater is intriguing. It does look like fresh ejecta, but from where? |
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Apr 29 2015, 09:39 PM
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#92
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Senior Member Group: Members Posts: 1585 Joined: 14-October 05 From: Vermont Member No.: 530 |
I can't stand this shift to 'trendy' websites either....but I have had visibility into the process behind the redesign for many of JPLs pages...and I can tell you, the demand for it isn't coming from designers, it's coming from management. I'm reminded of the old issue where webpages would break if they detected you were on a phone: https://imgs.xkcd.com/comics/server_attention_span.png ... now they apparently will just assume so. |
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Apr 30 2015, 12:40 AM
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#93
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IMG to PNG GOD Group: Moderator Posts: 2251 Joined: 19-February 04 From: Near fire and ice Member No.: 38 |
...i DO find that the MOST useful sites ( content wise) look like this
Yeah - I usually get happy when I find something like this (SPICE kernels, IMG files or stuff like that). Following up on that image, is the relatively crater-free area above the crater in this crop part of a massive landslide? Have we observed something similar on other bodies? The crater floor also appears to be of a relatively young age. I'm not sure about landslides outside of craters (and this may or may not be a landslide, it will be very interesting to see higher res images of this terrain) but of course big landslides inside of craters are quite common, for example I remembered this one on Iapetus: http://photojournal.jpl.nasa.gov/catalog/PIA06171 |
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Apr 30 2015, 01:25 AM
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#94
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Senior Member Group: Moderator Posts: 3233 Joined: 11-February 04 From: Tucson, AZ Member No.: 23 |
Reminds me a lot of the terracing on relatively fresh, large lunar craters like Tycho, so the stuff above it could be ejecta.
-------------------- &@^^!% Jim! I'm a geologist, not a physicist!
The Gish Bar Times - A Blog all about Jupiter's Moon Io |
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Apr 30 2015, 03:42 AM
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#95
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Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
It really does look strikingly lunar.
-------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
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Apr 30 2015, 08:05 AM
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#96
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Solar System Cartographer Group: Members Posts: 10184 Joined: 5-April 05 From: Canada Member No.: 227 |
I can't say that area above the crater looks like a landslide to me, but if it is, there is a very good precedent. Look at the lunar farside crater Tsiolkovsky... on its northwestern side, a massive and clearly delineated landslide or debris flow extends down into an older crater.
Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke Maps for download (free PD: https://upload.wikimedia.org/wikipedia/comm...Cartography.pdf NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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Apr 30 2015, 05:42 PM
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#97
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Junior Member Group: Members Posts: 65 Joined: 19-November 14 From: Milan, Italy Member No.: 7340 |
Another view of the southern hemisphere! http://photojournal.jpl.nasa.gov/jpegMod/PIA19321_modest.jpg
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Apr 30 2015, 08:00 PM
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#98
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Member Group: Members Posts: 715 Joined: 3-January 08 Member No.: 3995 |
Compared with the north polar area, there seems to be a paucity of small to medium sized craters, but more larger craters.
Perhaps the viewing angle due to Dawn's closer proximity may have something to do with it. |
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Apr 30 2015, 10:32 PM
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#99
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Senior Member Group: Members Posts: 4251 Joined: 17-January 05 Member No.: 152 |
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Apr 30 2015, 11:05 PM
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#100
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Founder Group: Chairman Posts: 14433 Joined: 8-February 04 Member No.: 1 |
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