Bright ground imprint of Ingenuity Mars helicopter blades by unknown effect on Sol 163

[Holger Isenberg]

The bright elongated X in the image center, is a negative shadow of the Ingenuity helicopter's rotor blades imprinted by some unknown process into the Martian surface. At that location of the imprint it sat there for about 11 days, from Sol 152 thru start to its eleventh flight on Sol 163 when the color image was taken during flight.

Detail image, contrast enhanced: https://areo.info/mars20/files/Sol163_X_imprint.jpg

The black shadow on the left is the normal shadow during flight, the elongated brighter than the surface X slightly right of the image center is the interesting feature.

This observation was published first by "tau" on August 11 on the following forum: http://www.unmannedspaceflight.com/inde ... t&p=253985

I see a good chance here for an electrostatic or electrochemical process as cause as other explanations like dust from the previous landing setting down over the landed helicopter is unlikely with so many turbulences happening during the landing and also the sharp edges of the imprints speak against that. I neither can be a light-induced effect as all those 11 days where it sat in that position where clear sunlit days with the shadow constantly moving over the surface. It almost looks like a radiation imprint from a single short flash, maybe the mysterious midnight flash? I forgot which frequency range this midnight flash was observed, radio or X-ray.

This observation was so far not discussed by NASA/JPL scientists and I could not find any public discussion about this on the net, except for the one above and a few twitter replies on that discussion.

Image with context and link to raw data on my automated Mars 2020 daily photo album:
https://areo.info/mars20/ecams/0163/tn/ ... o.jpg.html

[Maol]

Are you saying the X feature remained visible in several pictures for 11 days, or the chopper sat there for 11 days?

If it is a single image it is an artifact of the sunlight reflecting off the rotating propeller blades.

[Holger Isenberg]

When exactly the imprint appears and how long it took is unknown. It could be seconds or at maximum 11 Sols (about 11 Earth days).
11 days after the helicopter landed at the spot where later the X was seen, it started to its flight on Sol 163 and during that flight the X was seen in the color RTE camera image and in multiple monochrome navigation camera images from different points of view. It's definitely something fixed on the surface and it wasn't just dust as that would have been blown away during the start on Sol 163 before the photos.

You can see those other gray Navcam images on the unmannedspaceflight forum link or take a look at the raw images on https://mars.nasa.gov/mars2020/multimedia/raw-images by selecting Sol 163 and enable the checkboxes for the two helicopter camera on the right.

[Holger Isenberg]

A frozen tree shadow on Earth: https://imgur.com/gallery/TaUFy

That tree-pattern of ground frost was most likely created on an otherwise overcast day during a short clearing when the Sun could melt away all in direct light.

[Maol]

A frozen tree shadow on Earth: https://imgur.com/gallery/TaUFy

That tree-pattern of ground frost was most likely created on an otherwise overcast day during a short clearing when the Sun could melt away all in direct light.

The premise is valid, but Mars' atmosphere seems too tenuous to be able to condense anything to form ''frost".

I'll postulate something tenuous, I wonder if this is coincident with a Solar X Flare?

[Holger Isenberg]

The premise is valid, but Mars' atmosphere seems too tenuous to be able to condense anything to form ''frost".

I'll postulate something tenuous, I wonder if this is coincident with a Solar X Flare?

You can get normal morning water ground frost on Mars. Seen multiple times by Viking Lander 2: https://pages.uoregon.edu/imamura/123cs ... iking.html The white stuff there is water frost in the morning.

I like the solar x flare idea
I'll have to look for that midnight flash effect I read somewhere...