  The lunar Askaryan technique is a method to study the highest-energy cosmic
rays, and their predicted counterparts, the ultra-high-energy neutrinos. By
observing the Moon with a radio telescope, and searching for the characteristic
nanosecond-scale Askaryan pulses emitted when a high-energy particle interacts
in the outer layers of the Moon, the visible lunar surface can be used as a
detection area. Several previous experiments, at Parkes, Goldstone, Kalyazin,
Westerbork, the ATCA, Lovell, LOFAR, and the VLA, have developed the necessary
techniques to search for these pulses, but existing instruments have lacked the
necessary sensitivity to detect the known flux of cosmic rays from such a
distance. This will change with the advent of the SKA.
  The Square Kilometre Array (SKA) will be the world's most powerful radio
telescope. To be built in southern Africa, Australia and New Zealand during the
next decade, it will have an unsurpassed sensitivity over the key 100 MHz to
few-GHZ band. We introduce a planned experiment to use the SKA to observe the
highest-energy cosmic rays and, potentially, neutrinos. The estimated event
rate will be presented, along with the predicted energy and directional
resolution. Prospects for directional studies with phase 1 of the SKA will be
discussed, as will the major technical challenges to be overcome to make full
use of this powerful instrument. Finally, we show how phase 2 of the SKA could
provide a vast increase in the number of detected cosmic rays at the highest
energies, and thus to provide new insight into their spectrum and origin.
