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Lighting questions on the Perseverance landing video.


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10 hours ago, Ghideon said:

What is the correct size of a reflection under the conditions of the Perseverance landing?

Artist’s impression of Mars four billion years ago

ezgif-4-bb120b98a6cd.gif

Size of Jezero Crater on Mars, and size of Sun reflection inside that crater, which makes up less than 10% of Jezero Crater area.

jc

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Same bright spot size on Curiosity landing video.

Complete Mars Curiosity Descent - Full Quality Enhanced HD 1080p Landing + Heat Shield impact

ezgif-4-15cb0235f967

 
Edited by AlexandrKushnirtshuk
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10 hours ago, Ghideon said:

What is the correct size of a reflection under the conditions of the Perseverance landing?

With a diameter of Mars 6,700 km. and the diameter of the Jezero crater 50 km. The Sun should illuminate the entire crater completely and evenly.

Jcreftitl ezgif-7-5fcc6bebdabf.gif

38 minutes ago, iNow said:

Amazing how much this thread feels like one on a conspiracy site. 

Factual analysis only. No conspiracy at all in this thread.

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37 minutes ago, AlexandrKushnirtshuk said:

Oh, sorry, I thought you said you had nothing more to offer this thread...not that you have offered anything at all in actual fact, other then examples of ignoring all the realistic mundane possibilities, contacting NASA for yourself for explanations, the fact that other landers have been photographed and recorded during landing phase, which you denied, and of course ignoring the facts that Perseverence has been on the surface for a number of days now, to keep the other landers and rovers company.

38 minutes ago, iNow said:

Amazing how much this thread feels like one on a conspiracy site. 

Do you believe that is his agenda?😉 The ignorant based methodology he uses is certainly that of a conspiracist. 

4 minutes ago, AlexandrKushnirtshuk said:

With a diameter of Mars 6,700 km. and the diameter of the Jezero crater 50 km. The Sun should illuminate the entire crater completely and evenly.

Can you show us in detail your calculations for that bit of trivia claim?

5 minutes ago, AlexandrKushnirtshuk said:

Factual analysis only. No conspiracy at all in this thread.

Actually the opposite, as you have simply ignored all other possibilities, and refused to contact NASA for an explanation as any self respecting, fair dinkum person would with any genuine query.  

map of the Red Planet highlights the landing site for the Perseverance rover

Mars Landing Sites, Including Perseverance: This map of Mars shows the landing site for NASA’s Perseverance rover in relation to those of previous successful Mars missions. Full image and caption ›

https://mars.nasa.gov/mars2020/mission/science/landing-site/

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19 minutes ago, AlexandrKushnirtshuk said:

Factual analysis only. No conspiracy at all in this thread.

Apologies for any confusion Alex, I kept mentioning six or so previous landings, when it has been 9.  NASA certainly needs for congratulations for the time and effort needed for such momentous difficult missions.

32 minutes ago, AlexandrKushnirtshuk said:

With a diameter of Mars 6,700 km. and the diameter of the Jezero crater 50 km. The Sun should illuminate the entire crater completely and evenly.

After researching some of your previous hilarious claims of utmost certainty in other threads, I find it strange that you can ignore all the other mundane, everyday reasons for your trivial claim...you know, stuff like shadows of other landforms like mountains, hills etc, the colour and content of the soil, the vivid nature of light with refractive and reflective properties, and even the thin Martian atmosphere and content.

The only certainty in this thread, is that you are flogging a dead horse, whatever that horse maybe. 

9 landings old mate, and with examples of light phenomena in other examples also as I pointed out.

Yeah, I think we can all  move along now, nothing to see here. 

Edited by beecee
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In that thread of mine on the NASA forum, there is not a hint of conspiracy. I even removed the quotes from the words Sun and Mars from the first paragraphs of the text. And just in case, I made a screenshot.

Link to my NASA forum thread: https://forum.nasaspaceflight.com/index.php?topic=53173.0

Screenshot of that thread:

nasaforum.jpg

Edited by AlexandrKushnirtshuk
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I asked: What is the correct size of a reflection under the conditions of the Perseverance landing? Your response:

5 hours ago, AlexandrKushnirtshuk said:

Artist’s impression of Mars four billion years ago

You pick a few frames that show reflection of sun where the surface has water. How does an artist's impression of water reflection support your argument? Also note that in your linked video the dry surface reflection looks like below*. Conclusion: no support for your claim regarding sun reflections on mars surface.

image.png.3d70f6b0dcad3457dea7b147bb83bbe8.png

 

5 hours ago, AlexandrKushnirtshuk said:

With a diameter of Mars 6,700 km. and the diameter of the Jezero crater 50 km. The Sun should illuminate the entire crater completely and evenly.

Jcreftitl ezgif-7-5fcc6bebdabf.gif

Note that the overall brightness variations in your reference picture is similar to the variation in the frames from the video. So the explanation may be that the mars soil is looking slightly brighter or at the spot in the video from the Perseverance descent. Or any combination of this or other possibilities that we have not yet ruled out. Also note that the few frames used on the right seems post processed / compressed witch seems to enhance circular bands that may not be part of the original footage. I recommend a comparison with the original high resolution video rather than a gif.

 

Edit: Other readers may be interested in this with lots of engineering related information about the cameras used on the mission: https://link.springer.com/article/10.1007/s11214-020-00765-9

Quote

documentation of key events during entry, descent, and landing (EDL). There are a total of 16 cameras in the Perseverance engineering imaging system, including 9 cameras for surface operations and 7 cameras for EDL documentation.

 

 

*) source; link to timestamp where the frame is from: https://youtu.be/sBdioF65wNQ?t=3

 

Edited by Ghideon
added article link
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39 minutes ago, Ghideon said:

You pick a few frames that show reflection of sun where the surface has water. How does an artist's impression of water reflection support your argument? Also note that in your linked video the dry surface reflection looks like below*. Conclusion: no support for your claim regarding sun reflections on mars surface.

This animation shows the size (scale, diameter) of Sun's reflection on the surface of Mars regardless of the type of surface (water or soil). The reflection of the Sun on the ground in this computer animation was simply not displayed due to its dimness. Moreover, the reflection of the Sun on the ground of Mars cannot be focused into such a small bright spot as in the video of the Perseverance landing.

ezgif-4-bb120b98a6cd.gif

45 minutes ago, Ghideon said:

Note that the overall brightness variations in your reference picture is similar to the variation in the frames from the video. So the explanation may be that the mars soil is looking slightly brighter or at the spot in the video from the Perseverance descent.

Round bright spot on the video, and nothing bright and round on 2 photos of that area of Mars.

Round bright spots on two different landing videos are not moving on the surface, that is, they are located on the surface of Mars. They enter and leave field of view without changes of shape and size.

ezgif-7-5fcc6bebdabf.gif ezgif-4-15cb0235f967

Here is a link to video of Curiosity landing with better quality.

Mars Curiosity Descent - Ultra HD 30fps Smooth-Motion

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1 hour ago, AlexandrKushnirtshuk said:

This animation shows the size (scale, diameter) of Sun's reflection on the surface of Mars regardless of the type of surface (water or soil). The reflection of the Sun on the ground in this computer animation was simply not displayed due to its dimness. Moreover, the reflection of the Sun on the ground of Mars cannot be focused into such a small bright spot as in the video of the Perseverance landing.

Let's try to sum up what you have presented so far:

-Claim that a bright area in a video is sun reflection. 
-Claim that the reflection is "too small" according to some unknown measure.
-Support for your claim is an artist impression of mars as, it was believed to have looked like billions of years ago. The effect, light reflected from mars soil, that you discuss is invisible in the artists work.
 

Anyone able to spot a few logical issues with your line of reasoning? 

 

On 2/26/2021 at 1:02 AM, AlexandrKushnirtshuk said:

At the press conference on the video of the Perseverance landing, specialists analyzed almost every frame of these videos. Explained everything except this reflection (bright spot) on the surface of Mars. Personally, I think this is at least strange.

Maybe because possible explanations, such as opposition surge, is well known in the community and not a very important aspect of the landing?

Quote

The brightening of a rough surface, or an object with many particles, when illuminated from directly behind the observer. The term is most widely used in astronomy, where generally it refers to the sudden noticeable increase in the brightness of a celestial body such as a planet, moon, or comet as its phase angle of observation approaches zero. It is so named because the reflected light from the Moon and Mars appear significantly brighter than predicted by simple Lambertian reflectance when at astronomical opposition.

https://en.wikipedia.org/wiki/Opposition_surge

 

Here is an article specifically targeting the effect on mars:

Quote

The phase angle (angle between the Sun's incident light and the direction from the surface to the spacecraft) was near zero degrees. The sunlight reflecting from Mars near the zero phase angle produces the rare sun-glint phenomenon. The size and brightness of the glint depends on the physical properties of the surface (dust, sand, and rock distribution) and the atmosphere (haze/suspended dust). Studies of these images are expected to yield important information that can be compared with thermal emission observations.

 https://www.jpl.nasa.gov/images/opposition-surge-sunlight-glinting-off-mars

 

The opposition surge effect may be the reason why a bright spot appears in both missions' landing videos posted in this thread; Curiosity and Perseverance. The sun seems to be at a very similar angle relative the camera in both cases.

 

As beecee have said from the beginning:

On 2/25/2021 at 4:49 AM, beecee said:

I'm sure there's a logical mundane answer

 

Edited by Ghideon
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26 minutes ago, Ghideon said:

The opposition surge effect may be the reason why a bright spot appears in both missions' landing videos posted in this thread; Curiosity and Perseverance. The sun seems to be at a very similar angle relative the camera in both cases.

Sounds a jolly good working hypothesis to me, considering how little information there is to work with.

Thank you for this, I had not heard of the effect. +1

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6 hours ago, AlexandrKushnirtshuk said:

 

5 hours ago, AlexandrKushnirtshuk said:

In that thread of mine on the NASA forum, there is not a hint of conspiracy. I even removed the quotes from the words Sun and Mars from the first paragraphs of the text. And just in case, I made a screenshot.

Link to my NASA forum thread: https://forum.nasaspaceflight.com/index.php?topic=53173.0

Screenshot of that thread:

Stop avoiding the issue as well as questions and do what you have been asked...see NASA [ not some discussion forum where you have repeated your supposed incredulity] if you believe this is anything other then an absolute mundane non event. It is in fact, just that...a non event. Or as another seemingly sensible poster on that forum told you, concentrate on the incredible achievement with this landing as well as the others landings, something that strangely for someone denying pushing a conspiracy nonsense, you have yet even touched on. Why is that? 

Edited by beecee
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There’s no there there. We see shiny stuff on Mars all of the time. This is nothing new and has happened with past photos. 

Sometimes, it’s just plastic from the rover or landing vehicle itself:

https://www.cnet.com/news/curiositys-new-bright-shiny-object-is-actually-martian/

https://www.cnet.com/news/nasa-identifies-mars-rovers-mysterious-bright-object/

 

Other times, it’s a cosmic ray being detected by the camera equipment:

https://www.cnet.com/news/mysterious-light-in-mars-image-sparks-curiosity/


But in most cases, it’s just our feeble human brains forcing us to see patterns even when they’re not actually there, like this woman on Mars (and like is almost certainly happening here in this silly thread):

nasaspirit.jpg
 

Pareidolia strikes again!

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15 hours ago, AlexandrKushnirtshuk said:

Sun reflection on Earth from 400 km. and Mars from 10 km. I have nothing to add to this thread.

!

Moderator Note

This has become agonizingly apparent. I told you we don't stoop to the intellectual dishonesty of conspiracy here at SFN. If you open any more rigor-free, unreasoned, bad-faith crap threads like this again, you're going to be instantly booted. I'm going to ask that you be put on a list of people who are pre-approved for banning on their next infraction. 

This is a science discussion forum. Conspiracy is expecting us to do all the digging into your mere suspicions while you do nothing but question. It's not going to happen here with you anymore.

 
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