I have a question abouth IM-1/malapert(moon)

[dunwich]

The IM-1 lander’s mission was planned to last for one lunar day (about 14 Earth days). However, despite landing near the lunar south pole, its site experienced nightfall after a normal lunar day–night cycle. Given that Malapert is considered a Peak of Eternal Light (PEL), why did IM-1’s landing site still experience darkness instead of continuous sunlight?

IM-1 landing coordinates: 80.13°S 1.44°E https://lroc.im-ldi.com/images/1360
Malapert PEL coordinates: 86.04°S 2.7°E  http://'https://en.wikipedia.org/wiki/Peak_of_eternal_light#Lunar_south_pole
(the distance between the points should be roughly 180km if the terrain was flat)
(my links didn't work because they are https and the forum insist on adding http in front of it)

thank you for you answer

[daedalus1]

According to your wiki link there are no points on the moon in perpetual light, except tops of some crater rims. IM1 didn't land on a rim.

[Phil Stooke]

To be more accurate - there are no 'peaks of eternal light' on the Moon. There are a few very small places which are illuminated for up to 80% of a lunar day but the IM-1 landing site was not one of them.

Also  IM-1 landed near a crater called Malapert A at 80 degrees south. It did not land on the top of Mons Malapert (AKA Malapert Mountain) at 86 south which is a high illumination point (though not eternal). At 80 south you have a normal 14 days of sunlight like most other places.

[dunwich]

thank you for your answers.

If I might ask a follow up question?
If IM-1 was 401 meters tall would it have recieved PEL conditions.

(why 401 meters)
I visited:
https://quickmap.lroc.im-ldi.com/?prjExtent=-3561764.5266594%2C-1737400%2C3561764.5266594%2C1737400&activeDrawingLayer=%40%40user-defined&stack=3314&isCesiumDynamicEnabled=true&shadowsType=all&proj=10

I used the draw/search tool (3the icon)
at type a lat,lon in the main image I entered: 1.44, -80.13 followed by create point; 2.7, -86.04 create point.
I selected both points chose inspect in the right colum and it told me the height difference of 401.21 meters

[Phil Stooke]

What those elevations don't tell you is which nearby hills might be casting shadows across the landing site as the sun moves around the sky. The best-illuminated sites near the south pole would be eternally lit if not for mountains on the horizon which cast shadows as the sun passes behind them. The analysis is more complicated than you are suggesting and needs a digital elevation map of the region, not just elevations at a few points.