North Pole of the Moon
Radar maps can look like optical images, but they represent the amount of energy reflected back toward the transmitter by any given part of the Moon’s surface. The Arecibo Telescope’s radar wavelength of 70 cm penetrates 10 meters or more into the very dry lunar surface. When it bounced back to the Green Bank Telescope, (GBT), it reveals variations in the abundance of rocks larger than about 10 cm in diameter and differences in the chemistry of rocks that form the Moon’s crust.
Credit: B. Campbell, NAIC/NSF; NRAO/AUI/NSF
