Thats no Moon, Thats a space station!
If you need new pads anyway now is the time to swap them over as its not hard and you can check the sensor setup then.
My car did this recently and it was beacause the connector to the brake pad wasnt clipped on so wasnt making a full connection.
Audi S3 8L BAM 225 2002 - Ming Blue : Silver Heated Leather, Armrest, RNS-E & Bose, Alloy Mirrors, Gunmetal 18" RSTT`s, Sunroof, Cruise, AutoDim Mirror & usual S3 extras.
Mods : Revo Stg 2 & Select+, FMIC, 3" DP & 200 Cell Cat, 007P (New Piston), Jetex Filter & 80mm TIP & Heatshield, LED Sides & Fogs, Gen VW Aero Wipers, Full Powerflex Kit, Lowered on AP Shocks & Springs, 15mm Front & 20mm Rear Spacers, N249 Delete & Catch Can, AP TVR 4Pot Brakes & DS2500`s, Sachs DMF & Carbon/Kevlar Clutch