The lunar south pole is about on the center of the left rim of Shackleton Crater (A), 19 km in diameter. The Lunar Prospector orbiter impacted Shoemaker Crater (B), 51 km in diameter. The image was made in April 2005 by transmitting from Arecibo Observatory in Puerto Rico at 13 cm wavelength and receiving the radar echo with the Robert C. Byrd Green Bank Telescope in West Virginia.