Venera-13, Venera-14 Lander Images, Images generated from raw digital telemetry |
Venera-13, Venera-14 Lander Images, Images generated from raw digital telemetry |
May 8 2006, 06:23 PM
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#31
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Junior Member Group: Members Posts: 23 Joined: 30-June 05 Member No.: 422 |
It might look orange for a while but if you could stay there for a while your eyes would adjust and you would begin to find the orange increasingly less noticable. Until, of course, your eyes melt. On a more serious note, I've never seen the Venera landing sites pinpointed on the Magellan-based map of Venus. Anyone have any pointers? Heck, for that matter how well is our knowledge of the landing locations constrained? (I don't think Phil-o-vision's gonna help us much this time.) -Kevin |
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May 8 2006, 06:59 PM
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#32
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Dublin Correspondent Group: Admin Posts: 1799 Joined: 28-March 05 From: Celbridge, Ireland Member No.: 220 |
Until, of course, your eyes melt. ...or your skin burns, lungs and sinuses collapse or the rest. What a human eye and brain would actually perceive on the surface of Venus is a decidedly unlikely question to be actually answered by a real human eye any time soon, if ever. It will certainly be the last proper surface humans will ever visit in person, assuming we ever get back into the habit of doing that. |
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May 8 2006, 07:13 PM
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#33
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Junior Member Group: Members Posts: 40 Joined: 20-March 06 Member No.: 720 |
Remember when they used to claim that the Venusian atmosphere was so refracted that you could technically see all the way around the planet and right to the back of your head (or whatever special helmet was shielding it)? http://www.cosmographica.com/gallery/portf...fraction%20.htm Why is the refraction and the distortion of the Venus surface and atmosphere not visible in the venera images? |
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May 8 2006, 07:29 PM
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#34
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Dublin Correspondent Group: Admin Posts: 1799 Joined: 28-March 05 From: Celbridge, Ireland Member No.: 220 |
Why is the refraction and the distortion of the Venus surface and atmosphere not visible in the venera images? Quoting Don from his second or third post: QUOTE The camera is a photo multiplier tube, some fancy optics and a mechanical scanner. Don't laugh, a PMT is the absolute best light measuring device known to man, so the image quality was amazing. The mirror sat inside a 1-centimeter thick cylindrical quartz window, and inside the camera was a special lens that inverted the effect of the refraction of the window. (Russians know their optics!) I reckon it's likely that any additional refraction effects caused by the different refractive indices of the inner and outer atmospheres was included in that bit of optical wizardry. Other than that the only distortion would have resulted from temperature gradients in the external atmosphere whichare highly unlikely to be significant given the fairly short range covered. |
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May 8 2006, 08:21 PM
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#35
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Solar System Cartographer Group: Members Posts: 10153 Joined: 5-April 05 From: Canada Member No.: 227 |
Rem31 asked about the atmospheric distortion... that concept was grossly exaggerated before the Veneras landed. Now we know it doesn't really happen the way people used to suggest.
kwp asked: "On a more serious note, I've never seen the Venera landing sites pinpointed on the Magellan-based map of Venus. Anyone have any pointers? Heck, for that matter how well is our knowledge of the landing locations constrained? (I don't think Phil-o-vision's gonna help us much this time.)" I didn't check but I expect they are marked on Ralph Aeschliman's nice map (Ralphaeschliman.com) (edit - no they are not but his maps are worth a look anyway). I'll try to find a source. I'm going to be mapping them myself in a year or two. The locations are only known to a degree or so (about 100 km)... I assume. What we have not been able to do, and never will with existing landers, is know the exact location on a specific pixel of a Magellan image. The only way we can hope to do that is with descent imaging. This is really important for any future landers, because it is crucial to know what geologic unit you are on. Our ability to interpret existing Venera data is limited because we don't know this now. 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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May 8 2006, 08:30 PM
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#36
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Senior Member Group: Members Posts: 2530 Joined: 20-April 05 Member No.: 321 |
Don, I am sorry that I haven't clarified well enough my previous question. I wanted to know about how many pictures has all Russian sondas have taken? I seems that are as few as ten pictures in the total for all spacecrafts. Aren't it? Rodolfo If you mean surface pictures, two landers took 180-degree black and white panoramas; two other landers took 360-degree color (or partly color) panoramas. Due to the "economical" (and strange) scan concept, though, the panoramas do not show anywhere near 360 degrees of horizon, and concentrate more on the foreground. I didn't check but I expect they are marked on Ralph Aeschliman's nice map (Ralphaeschliman.com) (edit - no they are not but his maps are worth a look anyway). I'll try to find a source. I'm going to be mapping them myself in a year or two. The locations are only known to a degree or so (about 100 km)... Phil The Sky and Telescope Venus globe shows all (Venera, Pioneer, Vega) of the landers' locations, to whatever accuracy. I have it on my desk! I believe the exact content of the globe is here http://photojournal.jpl.nasa.gov/catalog/PIA03167 but the thumbnail is too small to check, and the full version is too big for me to bother with right now. |
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May 8 2006, 10:22 PM
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#37
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Senior Member Group: Members Posts: 2488 Joined: 17-April 05 From: Glasgow, Scotland, UK Member No.: 239 |
Until, of course, your eyes melt. -Kevin Kevin: Don't let the humans know about *our* solid eyes! They are not yet fit to use that knowledge in a responsible fashion. Bob Shaw -------------------- Remember: Time Flies like the wind - but Fruit Flies like bananas!
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Guest_DonPMitchell_* |
May 9 2006, 12:40 AM
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#38
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Guests |
Take a look at Abdrakhimov & Bazilevsky, The Geology of Venera and Vega Landing-Site Regions. Very nice paper.
The location of Venera-8 is known to within a radius of about 300 km, the later landers to within 150 km. The first impact, Venera-3, is known to within 800 km. Up through Venera-7, the Russians were aiming at the center of the visible face of Venus, so the landers could beam a tight signal straight up. The Vega aerostats were tracked to very high accuracy, by differential interferometry. But they drifted around to the other side of the planet, and nobody knows when the balloons failed after that. Basilevsky thinks Venera-9 landed on the side of a canyon, within the 150km disk, given the rocky terrain seen, and the steep incline (the probe was resting on a 20 degree incline, lucky to have remained upright!). |
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Guest_DonPMitchell_* |
May 9 2006, 06:59 PM
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#39
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Guests |
Here are some perspective reprojections of the Venera images. The optico-mechanical camera returns an image in spherical projection. These are sectioned up and transformed into overlapping perspective views, which are then blended together in Photoshop CS2. Missing pieces of terrain are created by duplication and reversal. And of course, the left and right sides of the images are actually views of the terrain that are 180 degrees apart, so some artistic license taken here.
[attachment=5515:attachment] [attachment=5516:attachment] |
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May 9 2006, 07:12 PM
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#40
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Junior Member Group: Members Posts: 40 Joined: 20-March 06 Member No.: 720 |
That are great images ,about of how it will look when you are standing on Venus. With 400+ degrees celsius of course and that is (less) funny.
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Guest_DonPMitchell_* |
May 9 2006, 07:28 PM
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#41
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That are great images ,about of how it will look when you are standing on Venus. With 400+ degrees celsius of course and that is (less) funny. Yep. Venus is slightly hotter than your kitchen oven when it is in "self cleaning" mode. So a person would be reduced to a fine white ash. Oh but maybe not in a reducing atmosphere -- you might just be carbonized into a charcoal statue of yourself. |
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May 9 2006, 08:05 PM
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#42
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Senior Member Group: Members Posts: 2488 Joined: 17-April 05 From: Glasgow, Scotland, UK Member No.: 239 |
Don:
Do you have any feel for the distances to the distant parts of the Venera-13 image? And are those bits of the image 'real'? If so, that looks like it was indeed a lucky little lander! Bob Shaw -------------------- Remember: Time Flies like the wind - but Fruit Flies like bananas!
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May 9 2006, 08:06 PM
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#43
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Junior Member Group: Members Posts: 23 Joined: 30-June 05 Member No.: 422 |
Missing pieces of terrain are created by duplication and reversal. And of course, the left and right sides of the images are actually views of the terrain that are 180 degrees apart, so some artistic license taken here. Fabulous! Despite having spent much time staring at your other (impressively) reprocessed Venera images this is the first time I can get my head around what the view might actually look like. In the interests of verisimilitude I'd love to see the same image with an overlay indicating which portions are "artistic license" rather than simple mathematical reprojections. (Or just lacking the missing pieces of terrain.) On a similar note, how much of the horizon is really captured in those little diagonal strips across the corners of the images? -Kevin |
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Guest_DonPMitchell_* |
May 9 2006, 08:12 PM
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#44
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Guests |
Fabulous! Despite having spent much time staring at your other (impressively) reprocessed Venera images this is the first time I can get my head around what the view might actually look like. In the interests of verisimilitude I'd love to see the same image with an overlay indicating which portions are "artistic license" rather than simple mathematical reprojections. (Or just lacking the missing pieces of terrain.) On a similar note, how much of the horizon is really captured in those little diagonal strips across the corners of the images? -Kevin You can look at the original panoramas I posted earlier to see what all of the original horizon is. The rest is the same image copied or reversed. The camera on the lander is only about 1 meter off the ground, so the features are smaller than you might think. Visibility is also quite limited in the thick atmosphere. The horizon is probably only hundreds of meters away. |
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May 9 2006, 09:16 PM
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#45
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Solar System Cartographer Group: Members Posts: 10153 Joined: 5-April 05 From: Canada Member No.: 227 |
Great stuff, Don.
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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