The presentation was made at IEEE PES 2011 General Meeting Super Sessions in July, 2011. In this presentation, Aurora was defined as a gap in protection which has the following characteristics: 1) Out-of-synch, open/close sequence of 1 or more breakers; 2) Induced torques can cause permanent damage to the generator; 3) Open/close as fast as 10 to 15 cycle, i.e., traditional protection will not trip (gap); 4) Physical/Cyber attack. The presenter describes Aurora’s definition, Idaho National Laboratory demonstration, Aurora alerts, mitigation and reports. Hardware Mitigation Devices (HMDs) are relays specifically designed to mitigate Aurora. The presenter concludes that HMD reliability mitigates Aurora’s High Impact Low Frequency event (HILF) and provides mitigation solution that does not interfere with, compromise, or jeopardize, the operation of the power system.