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I am well aware of the fact that the poles of the Moon are different from the rest of the regions in many ways. But in Google Earth's Moon, the poles are so different from what we would see if we were orbiting the Moon in a polar orbit.

The following image is the view of the South Pole of the Moon in Google Moon:

enter image description here

The following image shows the Lunar south polar region (>70°S): a mosaic of ~1500 images by Clementine (artificial satellite):

enter image description here

Image Source : Wikipedia

And the following is the view of the North Pole of the Moon in Google Moon:

enter image description here

The following image shows the Lunar north polar region mosaic by LRO:

enter image description here

Image Source : Wikipedia

The south pole in Google Moon is so bright compared to the image taken by Clementine and compared to the rest of the regions. What causes this huge shift in brightness? (I don't think our satellites have flashlights along with their cameras, unlike our smartphones) Further the north pole in Google Moon is something like a rubber balloon near its nozzle (stretched towards the pole) unlike the image by LRO. What is the reason for this?

Few reasons (along with associated doubts), which I think might be helpful to those who wish to answer, I could think of, due to which there is a huge difference between the poles and the rest of the regions in Google Moon are as follows:

  • The rest of the images (by Clementine and LRO) are planar, but the one on Google Moon is spherical (If this is the reason why are other regions in Google Moon normal?)

  • These images were taken by polar satellites. This could be a result of combining multiple images taken at different times (different brightness) (If this is the case, why didn't they choose one best shot?)

  • Maybe the way they tried to combine the images at poles caused this error.

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    $\begingroup$ Definitely the last point - the stitching software doesn't seem to be able to handle the polar regions correctly - likely caused by the (polar) coordinate system used. $\endgroup$
    – asdfex
    Nov 2, 2019 at 16:21
  • $\begingroup$ Flashlights dont work to illuminate a huge area of several square kilometers. There is not enough energy to produce such a huge light intensity. $\endgroup$
    – Uwe
    Nov 2, 2019 at 16:35
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    $\begingroup$ @Uwe, I was just joking :) $\endgroup$
    – Vishnu
    Nov 3, 2019 at 6:17

3 Answers 3

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Google Maps Moon likely uses a Simple Cylindrical projection for storing their map data. This is fine for the majority of the globe, but there are problems at the poles. Here are a few reasons why imagery of the poles is problematic:

  1. The data is prone to discontinuities because it has the entire top or bottom edge of the rectangular projection converging on one point.

  2. The poles of the Moon have areas in permanent darkness, and always has a significant portion of the surface in shadow. Any particular satellite pass has almost a random arrangement of light directions, which means it is exceedingly hard to get clear visual imagery of the poles.

  3. Due to high incidence angles with respect to the sun, the lit portions of the surface are not nearly as bright as a sunlit spot on the surface closer to the equator.

Furthermore, your non-Google Maps Moon images are likely hillshade, meaning the shading of the landscape is derived from height data (usually based on LIDAR) instead of imagery.

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The lighting is different at the poles. The sun is always very close to the horizon. There are some crater floors at the poles that never see sunlight. These crater floors are always inky black.

Likewise there are polar plateaus and mountain tops that enjoy nearly constant sunlight. Shadows cast across these plateaus are always long though. And these long shadows always run north to south or south to north. I suspect that might account for the radial burst appearance when they try to patch many polar images together.

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The strong distortions and star-like stripes are an artifact of Googles' image processing. For comparison, here is a screenshot of our own South Pole :

enter image description here

I increased the contrast to make the artifacts more visible - the ice itself just has less contrast than the rocky features of the Moon.

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