Is the animation/graphics for NASA's Webb telescope in error?

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  • #1
swampwiz
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I am looking at the webpage for the status, and it seems to me that there is a big error in the graphics:
https://webb.nasa.gov/content/webbLaunch/whereIsWebb.html?units=metric

It shows the Earth such that it appears that the axis of rotation is going from the bottom-right to the lop-left. Since Webb is moving away from the Sun, this would mean that the northern hemisphere dips toward the ecliptic on the sunny side, and not the night side, which would indicate summer for the northern hemisphere - and of course, the Webb launch & Lagrangian Point insertion is taking place in the winter.

What am I missing here?
 

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  • #2
DaveC426913
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It shows the Earth such that it appears that the axis of rotation is going from the bottom-right to the lop-left.
This?
1642368245575.png

Are you inferring that this is intended to depict an accurate tilt?
If so, surely they would have depicted the axis explicitly.


It's a fixed graphical icon - a 128x128 gif,
and it's resized and used elsewhere:

1642368704996.png
 
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  • #3
collinsmark
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Astute observation, but...

One thing to note is that the horizontal axis does not represent distance. It's meant to represent time.

So it doesn't make sense to think of the graphics as representing a snapshot of Earth + L2 point as viewed as its tangential orbit around the Sun. That's not what it's meant to convey.

It's just time: The time it takes for JWST to reach L2 insertion: Starting from the time of launch and ending at the time of L2 insertion.

So the graphics? They don't mean anything spatially. Their orientations don't matter since they don't represent anything outside of event times.

--------
Edit: Oops, I see now that there is a button that can be pressed such that the horizontal axis is changed to represent distance, rather than time.

Still, this distance is the scalar distance of the JWST in between the Earth and the L2 insertion point. Even in this case, it's not meant to be a snapshot of Earth and L2 point as seen from tangential perspective. Rather it's just a measure of scalar distance between the start and end (i.e., it's not meant to represent JWST's actual trajectory).
 
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  • #4
DaveC426913
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One thing to note is that the horizontal axis does not represent distance.
Well, unless you want it to.

1642393234243.png



they don't represent anything outside of event times.
... or distances ...

:wink:
 
  • #5
collinsmark
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Well, unless you want it to.

View attachment 295617



... or distances ...

:wink:
Yeah, I see that now. :blushing:

Still, it's not meant to represent an actual trajectory. I agree with you that the icons, and even the horizontal axis itself, are not meant to represent anything detailed. It's just a timeline -- or distance line -- and not a snapshot of a three dimensional, spatial system.
 
  • #6
Office_Shredder
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I hypothesize the center of that Earth graphic is the spot on Earth the telescope was launched from.

Edit: well maybe North/South, but the center looks like it's on the west coast of south America and actually it was launched from the east coast.
 
  • #7
JLowe
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I was under the impression it was just a simple graphical tool for our benefit and not to be analyzed too deeply.
 
  • #8
DaveC426913
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I hypothesize the center of that Earth graphic is the spot on Earth the telescope was launched from.

Edit: well maybe North/South, but the center looks like it's on the west coast of south America and actually it was launched from the east coast.
The horizontal line matches up with the equator as it crosses S.A.

I propose that we cannot trust it represents anything except a generic Earth.
 
  • #9
swampwiz
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This?
View attachment 295595
Are you inferring that this is intended to depict an accurate tilt?
If so, surely they would have depicted the axis explicitly.


It's a fixed graphical icon - a 128x128 gif,
and it's resized and used elsewhere:

View attachment 295596
Yes, that is it. I guess that now that I think about it, it is not really at any axis of tilt. And the outline of the continents is a bit sloppy (even for the pixelation).
 
  • #10
Motore
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Oh come on, it's just a simple GIF of Earth. I don't see how anyone can mistake it for something meaningful.
 

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