October 17, 2014
Seeing Into the Dark
Kandinksky crater image from MESSENGER Image Team
LPOD contributors have imaged the central peaks of craters hidden by shadows using light scattered by the illuminated crater rims. The Kaguya spacecraft did the same to image the floor of the Moon's Shackleton crater, and now MESSENGER scientists have applied the technique to investigate the shadowed floors of Mercurian polar craters that are known to contain ice. In the image pair above a normal exposure (left) shows the bright rim of 60 km wide Kandinsky crater, located at 89° N, whose interior is permanently shadowed. Using a longer exposure and extreme image processing the area surrounding the crater is saturated, but the floor of the crater is clearly visible (right). The reason this works is the high sensitivity of the MESSENGER MDIS camera. Only one amateur image that I am aware of reveals features of the shadowed floor of a lunar crater. Is it possible that instead of using a planetary camera made for imaging of relatively bright objects, that use of a camera designed for long exposure imaging of faint nebulae will make it easier to see into the darkness of lunar craters?
Nancy L. Chabot and colleagues (2014). Images of surface volatiles in Mercury’s polar craters acquired by the MESSENGER spacecraft. Geology. (full article)
Yesterday's LPOD: Two Lunar Brothers
Tomorrow's LPOD: Big Plain