Satellite Image Showing Damage from November 12, 2011 Blast at Military Base in Iran
You can draw a straight line through that blast site, indicating a series of explosions in a line, similar to what you would get from an aerial attack.
It makes sense to conduct such an operation as anonymously as possible. The Iranians have no idea who or where it is coming from and will scramble to protect their other facilities, revealing them to us for the next operation.