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Image released of permanently shadowed floor of Shackleton Crater

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.

Genesis cover

On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.

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  • J Fincannon

    If you drive straight down, its 7 km of 20-30 deg slope terrain. A challenge for a rover given a path is mostly in darkness.

  • James Street

    “7 km of 20-30 deg slope terrain. A challenge for a rover”

    J Fincannon, that got me wondering do rovers have brakes. A quick internet search says no, gears control everything:

    “The rovers I know of (Sojourner, MER, MSL) brake by not driving the wheels. The wheels do not free spin — they are connected to the motors by a high ratio gear box. If you tried to turn a rover wheel with your hands, you simply would not be able to, due to the high gear ratio and the resistance of the electric motor to motion.

    When power is applied to the motor, the wheel turns. When power is removed, the wheel stops.”

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