RE: [meteorite-list] SMART-1 SMASHES
Hi, I have another more mundane explanation of the 'square impact flash', looking at the pixel structure of those pictures on the website, (the image is a well compressed jpeg) they appear to have zoomed in on the jpg to show up the flash in as much detail as poss (to the point at which the jpg compression algorithm sqareifies the pixels), I suspect that the image has essentially pixilated (i.e the flash is smaller than the jpeg compression limit. I notice that if you tweak the image in a paint program the square flash is the same size as the surrounding 'square jpeg blocks'. Just one explanation, based on the pics I saw, the other is CCD elements don't respond too well to very sudden changes in brightness and become saturated with zoneing occurring around bright images - so could be an artifact of the ccd chip they imaged it with. Best Mark Ford -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Sterling K. Webb Sent: 03 September 2006 23:36 To: [EMAIL PROTECTED]; Meteorite List Subject: Re: [meteorite-list] SMART-1 SMASHES Hi, All, The space.com story says this (below) is an infrared image. There apparently is no visual light image. Interestingly, the 0.001 second flash is square, just like the spacecraft itself (SMART-1 is a cube just under one meter in dimension). The flash covers a square 22-23 pixels by 22-23 pixels. The webpages for the CFHT say the megacam used on this instrument has a resolution of 0.187 arcsecond per pixel. Assuming that's what was used for these photos, each pixel would resolve about 0.3463 meter at the mean distance of the Moon, and the observed flash would therefore cover a 7.6 to 8.0 meter square. Some of the things I find of interest: Despite being a very, very low grazing impact, the flash is not elongated at all in any direction. It's odd that the corners of the impactor are so well represented, when you would expect a vaporizing impact, necessary to create a crater, to be at least roughly spherical despite the impactor's square shape. Craters are round (or elliptical in the case of a grazing impact), not square, because the energetic event is spherically uniform in force. Are the corners really diffraction spikes in the image? No. The shape is quite different than diffraction spikes in the optics. And the CFHT has no obstructions to cause them... Compare the SMART impact image with this meteoroid impact on the Moon observed May 2, 2006 (although a much bigger hit than SMART-1): http://www.nasa.gov/vision/universe/solarsystem/13jun_lunarsporadic.html Why square? Frankly, I can think of no way of creating a square flash of light with an impact. But I can think of a scenario that could do it. SMART-1 is an aluminum box one meter square. You can look at the structure of the probe here: http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=31387 The bottom deck is lightened by eight triangular cut-outs that outline its square shape. Assume that it was traveling bottom down when it approached the lunar surface nearly horizontally (1 degree incidence, they said). If the first contact was with the top of a rock that projected a few meters above the surface of the Moon, it could easily have ripped open the bottom, ruptured the hydrazine tanks, and caused a hydrazine flash from INSIDE the square box structure (which now has an open almost-square bottom) which would project a square of light downward onto the otherwise unilluminated lunar surface, producing a geometrically square ground flash. This whole sequence of events might only occupy 1 to 2 milliseconds. After the 1 millisecond of illumination from inside the SMART-1 box, the probe's box structure would be violently tumbling and gyrating from the eccentric partial impact, ricocheting across the lunar surface from one irregular splat to the next, being ripped apart and leaving a trail of debris and regolith gouges across the lunar landscape, instead of a crater. This explanation would imply that we will be unable to detect a crater at the location (because there won't be one), so that's a kind of test of the notion. It's also likely that the debris trail would stretch for some distance; SMART-1 was traveling at 1930 meters per second at impact. Any other explanations of a square impact flash? Sterling K. Webb -- - Original Message - From: Darren Garrison [EMAIL PROTECTED] To: Meteorite List meteorite-list@meteoritecentral.com Sent: Sunday, September 03, 2006 9:18 AM Subject: Re: [meteorite-list] SMART-1 SMASHES http://esamultimedia.esa.int/images/smart_1/observation_SMART-1_hawaii_H .jpg http://www.esa.int/esaCP/SEM2N58ZMRE_index_0.html __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] SMART-1 SMASHES
Hello Moon watchers... Reporting back from NE Mexico... where the sky really cooperated for a change ! The view of the Moon was a comfortable 20 degrees above the horizon at time zero with windless superb seeing and a sharp 25X100 giant binocular (same as my lat/long). Rob's crater (which Sterling identified as Herschel) was very scenic in our view, too. What we found really dazzling along the terminator was - where two contrasty crater basins was blackened still by lunar night and the three dimensions relief perceptions so awesome: These craters were nearby - at 200 and 275 km southeast - relative to the planned impact site, respectively. If you saw them, according to the Lunar Atlas below, the names there are Crater Mee (132 km diameter) where the high rim on the left peeked above into the Lunar morning, as well as the low incident angle, long ellipsoid Crater Schiller (180 km major axis), too which had rims that were brighter and suggestive of long islands of light piercing the Luna's darkness. http://www.lunarrepublic.com/atlas/sections/g2.shtml With all the good things it had going for it, we saw no flash whatsoever at the appointed hour, and kept watching diligently for another 45 minutes, with superb resolution (better than the 10 km craters were discernable) all the while. There was no plume at all visible :-(. But this was the nicest views we've ever had of our celestial moonstruck companion. The skies were so friendly if was like a commercial for United and we did a couple of hours longer... G'Night! Doug Robert wrote: Anyone got anything to report? Unbelievably, the Moon slipped into the ONLY cloud in the sky here just ONE minute or so before impact! __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] SMART-1 SMASHES
http://esamultimedia.esa.int/images/smart_1/observation_SMART-1_hawaii_H.jpg http://www.esa.int/esaCP/SEM2N58ZMRE_index_0.html __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] SMART-1 SMASHES
nice, Darren Jerry Flaherty - Original Message - From: Darren Garrison [EMAIL PROTECTED] To: Meteorite List meteorite-list@meteoritecentral.com Sent: Sunday, September 03, 2006 10:18 AM Subject: Re: [meteorite-list] SMART-1 SMASHES http://esamultimedia.esa.int/images/smart_1/observation_SMART-1_hawaii_H.jpg http://www.esa.int/esaCP/SEM2N58ZMRE_index_0.html __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] SMART-1 SMASHES
Hi, All, The space.com story says this (below) is an infrared image. There apparently is no visual light image. Interestingly, the 0.001 second flash is square, just like the spacecraft itself (SMART-1 is a cube just under one meter in dimension). The flash covers a square 22-23 pixels by 22-23 pixels. The webpages for the CFHT say the megacam used on this instrument has a resolution of 0.187 arcsecond per pixel. Assuming that's what was used for these photos, each pixel would resolve about 0.3463 meter at the mean distance of the Moon, and the observed flash would therefore cover a 7.6 to 8.0 meter square. Some of the things I find of interest: Despite being a very, very low grazing impact, the flash is not elongated at all in any direction. It's odd that the corners of the impactor are so well represented, when you would expect a vaporizing impact, necessary to create a crater, to be at least roughly spherical despite the impactor's square shape. Craters are round (or elliptical in the case of a grazing impact), not square, because the energetic event is spherically uniform in force. Are the corners really diffraction spikes in the image? No. The shape is quite different than diffraction spikes in the optics. And the CFHT has no obstructions to cause them... Compare the SMART impact image with this meteoroid impact on the Moon observed May 2, 2006 (although a much bigger hit than SMART-1): http://www.nasa.gov/vision/universe/solarsystem/13jun_lunarsporadic.html Why square? Frankly, I can think of no way of creating a square flash of light with an impact. But I can think of a scenario that could do it. SMART-1 is an aluminum box one meter square. You can look at the structure of the probe here: http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=31387 The bottom deck is lightened by eight triangular cut-outs that outline its square shape. Assume that it was traveling bottom down when it approached the lunar surface nearly horizontally (1 degree incidence, they said). If the first contact was with the top of a rock that projected a few meters above the surface of the Moon, it could easily have ripped open the bottom, ruptured the hydrazine tanks, and caused a hydrazine flash from INSIDE the square box structure (which now has an open almost-square bottom) which would project a square of light downward onto the otherwise unilluminated lunar surface, producing a geometrically square ground flash. This whole sequence of events might only occupy 1 to 2 milliseconds. After the 1 millisecond of illumination from inside the SMART-1 box, the probe's box structure would be violently tumbling and gyrating from the eccentric partial impact, ricocheting across the lunar surface from one irregular splat to the next, being ripped apart and leaving a trail of debris and regolith gouges across the lunar landscape, instead of a crater. This explanation would imply that we will be unable to detect a crater at the location (because there won't be one), so that's a kind of test of the notion. It's also likely that the debris trail would stretch for some distance; SMART-1 was traveling at 1930 meters per second at impact. Any other explanations of a square impact flash? Sterling K. Webb -- - Original Message - From: Darren Garrison [EMAIL PROTECTED] To: Meteorite List meteorite-list@meteoritecentral.com Sent: Sunday, September 03, 2006 9:18 AM Subject: Re: [meteorite-list] SMART-1 SMASHES http://esamultimedia.esa.int/images/smart_1/observation_SMART-1_hawaii_H.jpg http://www.esa.int/esaCP/SEM2N58ZMRE_index_0.html __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] SMART-1 SMASHES
Sterling wrote: each pixel would resolve about 0.3463 meter at the mean distance of the Moon, and the observed flash would therefore cover a 7.6 to 8.0 meter square. ... Any other explanations of a square impact flash? Hello Sterling: 35 cm on the Lunar surface? That would be Totally Unbelievable! A camera connected to a telescope on Earth that can distinguish a foot by a foot (35cm ) square on the moon through the Earth's atmosphere, they could actually take some nice pictures of the old Lunar modules and stuff right from Hawaii. I know technology has progressed but that would be awesome! If Dawe's Limit (theoretical in quotes) has any relevance to the telescope-camera combination. The very best that could be done would be about 60 meters x 60 meters per pixel. But their pixels in the image with atmosphere and all, resolution appears to be over ten times worse. I took a Sear's Stanley tape measure to the picture of the explosion from the Canada France Hawai'i Telescope which they say is 200x200 km, and from that get that the flash is about 15 kilometers by 15 kilometers, not your 8 by 8 meters (don't follow how you got that (there's a lot of theoretical atmospheric and optical limits beyond me to deal with since the camera has a big reflector and a quarter of a million miles in front of it.) Sorry about the low tech check. As a cross check, in their published image there are indeed about 22-23 pixels up and down and across - sometimes. That would say that it is about 11.5 km x 11.5 km, only 2 million times more area than you suggested. (400 x 400 pixel image size, the blast covers (23/400*200,000)^2). Note how many features look like squares and rectangles (better in my enlarged image below). http://www.cfht.hawaii.edu/News/Smart1/ Then, if 15 km equals 23 pixels, they are getting 650 METERS (OK maybe as low as 450 meters) per pixel, not 35 CENTIMETERS per pixel and Big Brother can't read the license plates on the Lunar rovers yet. As to the square shape, I think it's like looking at clouds on the Oklahoma plains and you see what pleasures you. There appear to be spashes around all the edges to me and some nice new SMART-tektites to go-n-get. I can easily count 30 pixels up and down in some parts. But maybe you've got a good theory there, nothing proves it's not a square. I've posted an enlargement of the explosion showing with the individual pixels posted on the CFHT page here: www.diogenite.com/smart.JPG for anyone curious about the shape of the explosion, which clearly shows rays of light like splashes and, maybe or maybe not, coincidentally, four of them defining Sterling's square. It is even more coincidental that the square would happen to be perfectly setting horizontal in the image - or yikes, that could that be enhancing a perception or illusion. Try rotating it in your image viewer. Who knows. The Shadow? Best wishes, Doug PD, IR might be the favorite choice since it gives better night vision, so, I guess we all forgot to put the Russian goggles on our scopes and binocs... In any of the articles did it actually say someone saw real time a flash in the visual light's range? Sterling K. Webb -- - Original Message - From: Darren Garrison [EMAIL PROTECTED] To: Meteorite List meteorite-list@meteoritecentral.com Sent: Sunday, September 03, 2006 9:18 AM Subject: Re: [meteorite-list] SMART-1 SMASHES http://esamultimedia.esa.int/images/smart_1/observation_SMART-1_hawaii_H.jpg http://www.esa.int/esaCP/SEM2N58ZMRE_index_0.html __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] SMART-1 SMASHES
Ouch, Doug! You got me again. It's 346.3 meters per pixel, not 0.3463 meters. Multiply everything by 1000. Note to self: no more cyphering in the head while heavily medicated. Method: mean distance = 400,000 km rough (apogee = 405,696 km; perigee = 363,104 km) Divide by 60 x 60 x 60 (deg x min x sec) = 216,000 yields about 1850 meters per arc-second, then multiply by 0.187 arc-second per pixel which is about halfway between 18 squared (324) and 19 squared (361). I then repeated these mental steps on a calculator to get more precise results but somehow managed to forget that it was KILOmeters, not meters... Like I said, Heavily Medicated... The 200 km size of the image square (this page wasn't up when I checked them this morning, or I couldn't find it) indicates that they were either binning the pixels in the CCD, hence about 346.3 x 2 = 692.6 meters per pixel, or I made a wrong assumption about the view of view they were using. (The CFHT has three different setups for differing fields of view.) http://www.cfht.hawaii.edu/News/Smart1/ The corners ARE diffraction spikes, they say, at 45 degrees to the image orientation, which clearly shows in the animated gif of the impact (now that they've had time to clean the images up). The contour map of the flash shows a slightly elliptical flash elongated in the direction of motion. Their MVA chart of the impact site shows it to be on a hillside, a not-unlikely outcome if you're zapping almost horizontally over the Moonscape at 1930 m/sec. Not safe driving. It's a very noisy low contrast image, straining to get the flash location, no doubt. Lehmann C and Drebbel D show up in the images, but the rest of terrain is just a jumble. The originally released raw image looked too square (so over-saturated). That helped to fool me, but it was greatly aided by making too many quick assumptions, speculating too easily and facilely, and -- oh, yeah -- forgetting that it was kilometers instead of meters. Just let me be a bad example for everybody... Sterling K. Webb - - Original Message - From: MexicoDoug [EMAIL PROTECTED] To: Meteorite Mailing List meteorite-list@meteoritecentral.com Sent: Sunday, September 03, 2006 7:55 PM Subject: Re: [meteorite-list] SMART-1 SMASHES Sterling wrote: each pixel would resolve about 0.3463 meter at the mean distance of the Moon, and the observed flash would therefore cover a 7.6 to 8.0 meter square. ... Any other explanations of a square impact flash? Hello Sterling: 35 cm on the Lunar surface? That would be Totally Unbelievable! A camera connected to a telescope on Earth that can distinguish a foot by a foot (35cm ) square on the moon through the Earth's atmosphere, they could actually take some nice pictures of the old Lunar modules and stuff right from Hawaii. I know technology has progressed but that would be awesome! If Dawe's Limit (theoretical in quotes) has any relevance to the telescope-camera combination. The very best that could be done would be about 60 meters x 60 meters per pixel. But their pixels in the image with atmosphere and all, resolution appears to be over ten times worse. I took a Sear's Stanley tape measure to the picture of the explosion from the Canada France Hawai'i Telescope which they say is 200x200 km, and from that get that the flash is about 15 kilometers by 15 kilometers, not your 8 by 8 meters (don't follow how you got that (there's a lot of theoretical atmospheric and optical limits beyond me to deal with since the camera has a big reflector and a quarter of a million miles in front of it.) Sorry about the low tech check. As a cross check, in their published image there are indeed about 22-23 pixels up and down and across - sometimes. That would say that it is about 11.5 km x 11.5 km, only 2 million times more area than you suggested. (400 x 400 pixel image size, the blast covers (23/400*200,000)^2). Note how many features look like squares and rectangles (better in my enlarged image below). http://www.cfht.hawaii.edu/News/Smart1/ Then, if 15 km equals 23 pixels, they are getting 650 METERS (OK maybe as low as 450 meters) per pixel, not 35 CENTIMETERS per pixel and Big Brother can't read the license plates on the Lunar rovers yet. As to the square shape, I think it's like looking at clouds on the Oklahoma plains and you see what pleasures you. There appear to be spashes around all the edges to me and some nice new SMART-tektites to go-n-get. I can easily count 30 pixels up and down in some parts. But maybe you've got a good theory there, nothing proves it's not a square. I've posted an enlargement of the explosion showing with the individual pixels posted on the CFHT page here: www.diogenite.com/smart.JPG for anyone curious about the shape of the explosion, which clearly shows rays of light like splashes and, maybe or maybe not, coincidentally, four of them
