Exploration Shackleton_(crater)

shackleton imaged clementine.

from perspective of earth, crater lies along southern limb of moon, making observation difficult. detailed mapping of polar regions , farside of moon did not occur until advent of orbiting spacecraft. shackleton lies entirely within rim of immense south pole-aitken basin, 1 of largest known impact formations in solar system. basin on 12 kilometers deep, , exploration of properties provide useful information lunar interior.

a neutron spectrometer on board lunar prospector spacecraft detected enhanced concentrations of hydrogen close northern , southern lunar poles, including crater shackleton. @ end of mission in july 1999, spacecraft crashed nearby crater shoemaker in hope of detecting earth-based telescopes impact-generated plume containing water vapor. impact event did not produce detectable water vapor, , may indication hydrogen not in form of hydrated minerals, or impact site did not contain ice. alternatively, possible crash did not excavate enough regolith liberate significant quantities of water vapor.

from earth-based radar , spacecraft images of crater edge, shackleton appears relatively intact; young crater has not been eroded subsequent impacts. may mean inner sides relatively steep, may make traversing sides relatively difficult robotic vehicle. in addition, possible interior floor might not have collected significant quantity of volatiles since formation. other craters in vicinity considerably older, , may contain significant deposits of hydrogen, possibly in form of water ice. (see shoemaker (lunar crater), example.)

radar studies preceding , following lunar prospector mission demonstrate inner walls of shackleton similar in reflective characteristics of sunlit craters. in particular, surroundings appear contain significant number of blocks in ejecta blanket, suggesting radar properties result of surface roughness, , not ice deposits, suggested radar experiment involving clementine mission. interpretation, however, not universally agreed upon within scientific community. radar images of crater @ wavelength of 13 cm show no evidence water ice deposits.

optical imaging inside crater done first time japanese lunar orbiter spacecraft kaguya in 2007. did not have evidence of significant amount of water ice, down image resolution of 10 m per pixel.

on november 15, 2008, 34-kg probe made hard landing near crater. moon impact probe (mip) launched indian chandrayaan-i spacecraft , reached surface 25 minutes later. probe carried radar altimeter, video imaging system, , mass spectrometer, used search water.