Chang'e-4 farside landing mission |
Chang'e-4 farside landing mission |
Jan 11 2019, 10:05 PM
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#151
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Member Group: Members Posts: 684 Joined: 24-July 15 Member No.: 7619 |
Amazing how fractal the cratering is. Well, amazing when I realize I have no idea of vertical height when looking straight down. I've heard from family who flew over the Atlantic, Pacific and Gulf of Mexico that ocean waves are fractal. You can't tell vertical height by looking down, waves at 10-feet up look just like waves at 100-feet up, which look just like waves at 1,000-feet up. That's why, when you're on a parachute, you don't look down; you look at the horizon to judge altitude, and you don't release the parachute harness until your feet hit the water. - Interesting whether the fractal dimensions of cratering might constrain the atmospheric properties of moons and planets? Curious- are there any papers on "fractal dimensions of lunar craters" addressing the range of sizes? |
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Jan 11 2019, 10:07 PM
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#152
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Member Group: Members Posts: 808 Joined: 3-June 04 From: Brittany, France Member No.: 79 |
Thanks Phil. The resolution of images on the quickmap was enough to locate the landing site.
Here is a montage I did to help locate it. And my guess on the orientation of Chang'E 4 based on the shadows and position of craters: -------------------- |
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Jan 11 2019, 11:36 PM
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#153
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Member Group: Members Posts: 238 Joined: 15-January 13 Member No.: 6842 |
Phil, where did you download this picture? I'm on the QuickMap LROC website but the resolution is not as good as your picture. For everybody's convenience, here's a high-quality NAC strip of the area: http://wms.lroc.asu.edu/lroc/view_lroc/LRO....0/M134022629LE The landing site is slightly below the centre of the image strip. 200% scale crop: -------------------- Curiosity rover panoramas: http://www.facebook.com/CuriosityRoverPanoramas
My Photosynth panoramas: http://photosynth.net/userprofilepage.aspx...;content=Synths |
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Jan 12 2019, 06:25 PM
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#154
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Solar System Cartographer Group: Members Posts: 10128 Joined: 5-April 05 From: Canada Member No.: 227 |
I know several of us were looking for the landing location in images like these before we saw the panorama. I looked at this place among many others, but I thought the hazard avoidance system would divert the lander away from a place like that which is surrounded by craters. There are nice smooth spots close by, to the west or northeast. But it's all about the scale of the hazard avoidance, I suppose. We did get a nice level area between the craters.
Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke 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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Jan 12 2019, 10:23 PM
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#155
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Solar System Cartographer Group: Members Posts: 10128 Joined: 5-April 05 From: Canada Member No.: 227 |
While waiting for news of any activity on the 12th, here is a comparison of horizon features between the panorama and an LRO wide angle (heavily processed) image.
The central peak is visible, but Ba Jie crater is not. More than half of the horizon is the rim of Von Karman. The small hill about 10 km north of the lander, which might make a good target for the traverse, is probably visible as a low ridge labelled X here. Phil EDIT: My crater 'C' might be the one higher up on the rim of the main crater, with ridge D adjacent to it. -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke 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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Jan 13 2019, 08:19 AM
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#156
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Member Group: Members Posts: 238 Joined: 15-January 13 Member No.: 6842 |
I know several of us were looking for the landing location in images like these before we saw the panorama. I looked at this place among many others, but I thought the hazard avoidance system would divert the lander away from a place like that which is surrounded by craters. There are nice smooth spots close by, to the west or northeast. But it's all about the scale of the hazard avoidance, I suppose. We did get a nice level area between the craters. Phil The landing footage shows the craft pausing briefly when over that location, seemingly detecting an even space between those craters, and "making the decision" to land there. Simple and effective, just like what Chinese would do. https://www.youtube.com/watch?v=JJi_YEubKCY&t=1m54s -------------------- Curiosity rover panoramas: http://www.facebook.com/CuriosityRoverPanoramas
My Photosynth panoramas: http://photosynth.net/userprofilepage.aspx...;content=Synths |
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Jan 13 2019, 08:46 AM
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#157
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Member Group: Members Posts: 238 Joined: 15-January 13 Member No.: 6842 |
"The space probe is moving south across the Mün"
Excellent video processing and analysis here. https://www.youtube.com/watch?v=unEbg_dt3DM -------------------- Curiosity rover panoramas: http://www.facebook.com/CuriosityRoverPanoramas
My Photosynth panoramas: http://photosynth.net/userprofilepage.aspx...;content=Synths |
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Jan 13 2019, 02:02 PM
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#158
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Member Group: Members Posts: 185 Joined: 4-January 19 Member No.: 8523 |
Panoramas from chang'e-3 and chang'e-4. I expected the number and pattern of the impact craters to be more diferent beetween the two landing sites, it apears to have double of small craters (less than 1 meter) on the darkside.
-------------------- "The Earth is a very small stage in a vast cosmic arena"
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Jan 13 2019, 02:19 PM
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#159
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Member Group: Members Posts: 122 Joined: 3-September 12 From: Almeria, SE Spain Member No.: 6632 |
I think we have to be careful with generalizing
"lunar farside" = "heavily cratered" = "this landing spot". The first "=" is generally true, but the specific Cháng'é-4 landing site is a lava flooded crater and hence should rather have properties of (near side) Mare areas. Untypical for far side in general. The difference in craters should be more indicative to age than to "near" vs "far" side. Thorsten |
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Jan 13 2019, 08:03 PM
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#160
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Member Group: Members Posts: 289 Joined: 29-December 05 From: Ottawa, ON Member No.: 624 |
Chang'e 3 landed on lunar maria, Chang'e 4 on lunar highlands, which is a big difference especially in age, so I'd expect more craters in a highland area. Of course, that depends on the age of the basin in Von Karman.
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Jan 14 2019, 05:51 AM
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#161
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Solar System Cartographer Group: Members Posts: 10128 Joined: 5-April 05 From: Canada Member No.: 227 |
Von Karman is filled with basalt lava flows, probably not very different in age than typical mare basalts on the Earth-facing side of the Moon. Von Karman is in the highlands but its floor is not highland, in other words. But these things are deceptive. Because highland surfaces are older they have a thicker regolith, and it affects the survival of small craters during impact-generated siesmic shaking. Sometimes highland surfaces can look smoother and younger just because their craters are more softened by shaking. A slope helps that process, so the rolling topography of highland areas is ideal for erasing craters in this way.
Here is an example from Flamsteed, the almost completely buried crater in which Surveyor 1 landed in 1966. Mare basalt at the top, low relief highland surface at the bottom. The image is about 800 m wide, 1.9 south, 43.0 west. More craters in a given area on the mare, but the highlands are older. At this scale they just don't preserve craters. Larger craters are not erased this way so at broad scales the basic rule 'older = more craters' is true. Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke 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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Jan 14 2019, 07:30 PM
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#162
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Member Group: Members Posts: 547 Joined: 1-May 06 From: Scotland (Ecosse, Escocia) Member No.: 759 |
Lovely little color video of Yutu-2 driving away from the Chang'e-4 lander and executing the 180 degree turn ...
Yutu-2 driving away from lander |
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Jan 15 2019, 06:42 AM
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#163
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Senior Member Group: Members Posts: 1414 Joined: 26-July 08 Member No.: 4270 |
China's Chang'e-4 probe conducts first bio test on moon as first plant grows
https://news.cgtn.com/news/3d3d414f7949444d...54/share_p.html Edit: From this Global Times article. QUOTE Chinese media state that the experiment contains six species: cotton, rapeseed, potato, arabidopsis, fruit fly and yeast, with Xinhua reporting that no signs of growth have been found among the species other than cotton.
-------------------- -- Hungry4info (Sirius_Alpha)
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Jan 15 2019, 09:03 AM
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#164
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Junior Member Group: Members Posts: 31 Joined: 24-February 17 From: California Member No.: 8127 |
[quote name='Phil Stooke' post='243419' date='Jan 13 2019, 09:51 PM']Von Karman is filled with basalt lava flows, probably not very different in age than typical mare basalts on the Earth-facing side of the Moon. Von Karman is in the highlands but its floor is not highland, in other words...
Phil Very true. In fact, where Chang'e-4 landed is approximately -6km relative to the moon's mean radius. Definitely not highlands, and instead is lowlands within the huge Von Karman crater floor. |
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Jan 15 2019, 06:41 PM
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#165
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Solar System Cartographer Group: Members Posts: 10128 Joined: 5-April 05 From: Canada Member No.: 227 |
I have been following the discussion here:
http://www.9ifly.cn/thread-5819-70-1.html (in translation) which seems to be saying that a power failure has ended the biological experiment. Does anyone have any other information? Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke 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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