Tag: ShadowCam

There likely is little or no ice in the Moon’s permanently shadowed craters

11:47 am

Shadowcam-LRO mosaic
The floor of Shackleton Crater showing no obvious ice deposits,
as seen by Shadowcam. The black cross marks the south pole.
Click for original image.

This week the 55th annual Lunar and Planetary Science Conference is being held in Texas. The conference was originally established in connection with the Apollo missions to allow scientists to release their Moon research results. It quickly morphed into an annual event covering research from the entire planetary research community.

I have reviewed the abstracts for this year’s meeting, and culled what I think are the most significant new results from the conference, which I will report on in the next few posts.

We begin however with possibly the most important result from the conference, given by the science team for the ShadowCam instrument on South Korea’s Danuri lunar orbiter. That low-light camera was designed to take high resolution pictures of the permanently-shadowed craters of the Moon, to see if there was any visible or obvious ice hidden there. Though the science team presented a number of papers, the summary paper [pdf] by the instrument’s principal investigator, Mark Robinson of Arizona State University, gave the bottom line:

The data so far is finding very little evidence of water ice in these dark regions.
» Read more

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The scientific results from South Korea’s first lunar orbiter Danuri

9:56 am

floor of Shackleton Crater
The floor of Shackleton Crater at the Moon’s
south pole. Click for original image.

Link here. The article provides a good summary, with three results of significance:

  • NASA’s Shadowcam camera successfully obtained low light images of the permanently shadowed craters at the Moon’s south pole. One of those images is to the right. All images showed no obvious evidence of ice. The arrow points to the track of a boulder that rolled down the slope.
  • A gamma-ray detector, designed to map the chemcial surface of the Moon, ended up detecting many intergalactic gamma-ray bursts, including the brightest ever in October 2022 that was observed by numerous detectors.
  • Data of the Moon’s magnetic field suggested the far side was “more electrically conductive than the near side,” a result that scientists said “doesn’t make sense.”

Danuri is still functioning, long after its primary mission was completed, and could continue to operate for years yet.

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Image released of permanently shadowed floor of Shackleton Crater

11:01 am

Shadowcam-LRO mosaic
Click for original image.

NASA today released a mosaic combining images from Lunar Reconnaissance Orbiter’s high resolution camera LROC and the Shadowcam camera on South Korea’s Danuri lunar orbiter that shows for the first time the entire permanently shadowed floor of Shackleton Crater at the Moon’s south pole.

That mosaic, cropped, reduced, and sharpened to post here, is to the right. I have added the black cross to mark the location of the south pole, just inside Shackleton, the large crater on the right. The inset shows the floor of the crater at higher resolution.

LROC can capture detailed images of the lunar surface but has limited ability to photograph shadowed parts of the Moon that never receive direct sunlight, known as permanently shadowed regions. ShadowCam is 200-times more light-sensitive than LROC and can operate successfully in these extremely low-light conditions, revealing features and terrain details that are not visible to LROC. ShadowCam relies on sunlight reflected off lunar geologic features or the Earth to capture images in the shadows.

Thus, in the mosaic to the right the interior of Shackleton was imaged by Shadowcam, and then placed on a mosaic of LROC pictures.

If you click on the full image at high resolution and look closely at the crater floor, it is difficult to determine if there is any ice there. There are several mounds that could be ice, but could also be accumulated dirt and debris. What is most significant however is the smooth interior walls of the crater. It appears it will very possible for a rover to drive down those walls and into Shackleton.

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Shadowcam on South Korea’s Danuri lunar orbiter sees no obvious ice in the permanently shadowed interior of Spudis crater

10:30 am

Overview map

Using Shadowcam, a camera built by Arizona State University that is on South Korea’s Danuri lunar orbiter and is designed to see into very dark regions of little light, scientists have obtained optical images showing the permanently shadowed interior of Spudis Crater, located only about ten miles from the Moon’s south pole.

That picture is below. To the left is an annotated overview created from Lunar Reconnaissance Orbiter (LRO) high resolution images. The white box inside Spudis Crater indicates the area covered by the section of the Shadowcam image I have focused on. The red outlines indicate areas that are thought to be permanently shadowed. The relatively flat ridgeline between Shackleton and Spudis is one of the prime future landing sites for NASA’s Artemis program.
» Read more

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No ice inside permanently shadowed crater near Moon’s south pole?

12:44 pm

Marvin crater as seen by Shadowcam
Click for original image.

Overview map

Using a camera on South Korea’s lunar orbiter Danuri, dubbed Shadowcam and designed to look into the permanently shadowed craters at the Moon’s poles, scientists have taken an image that sees into the forever dark region of one such crater.

The picture to the right, released on March 13, 2023 by the Shadowcam science team, is of the crater Marvin, located about 16 miles to the east of the south pole. The pink outline indicates the area that is thought to be permanently shadowed.

The second image to the right provides a wider view of the south pole region, with the craters labeled and outlined by the green lines. The orange lines mark permanently shadowed areas. The white box indicates the approximate area covered by the Shadowcam picture. One of the candidate landing sites for Starship, as part of NASA’s Artemis program, is the eastern rim of Shackleton, essentially at the south pole itself.

Previous data suggests that ice should be found in those permanently shadowed areas, because other orbiters have detected evidence of hydrogen there. The Shadowcam picture above however shows nothing that strongly suggests the presence of ice, unless that darker flat area on the floor of the crater is ice-infused dust. If so however, it is quite ancient and solid, based on the presence of several craters within it.

The press release makes no mention of this question, probably because the scientists are still analyzing the data. This first look however suggests the ice is not there, or is in a form that is going to require a lot of processing to extract the water from it.

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American camera snaps picture of shadowed floor of Shackleton crater

10:03 am

floor of Shackleton Crater
Click for original image.

Using ShadowCam, a NASA-funded camera designed to take high resolution images of the permanently shadowed regions on the Moon, scientists have snapped the first picture of shadowed floor of Shackleton crater.

That image, reduced to post here, is to the right. I have added some labels to clarify what we are seeing. The arrow points to a boulder track caused when the boulder rolled down the crater rim slope.

The camera will be used to image the moon’s permanently shadowed regions with a resolution of better than 6.6 feet (2 meters) per pixel

ShadowCam is one of six instruments on the South Korean lunar orbiter, Danuri, which is now in lunar orbit and beginning its science phase. This was therefore only a successful test image to make sure the camera was working as planned.

Though the area photographed was in shadow (otherwise it would have saturated ShadowCam’s sensitive camera), this first image appears to show no ice at the base of the crater. This simply could be that this part of the crater floor is not permanently shadowed, but gets illuminated enough to melt off any ice. Or it could be that no ice exists in these places. We need to wait and see.

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