The Antarctic Impulsive Transient Antenna, a NASA long duration balloon payload with an array of 40 broadband UHF antennas, surveys of order 1M cubic km of ice in its field of view at any time for impulsive radio events associated with ultra-high energy neutrino interactions. We describe the astrophysics that motivates ANITA, the background for the technique, and report on some preliminary results of ANITA's first flight, completed in January of this year.