How long is the Alien Missile Acid effect?

[Raziel666]

The Alien rockets don't deal much damage by itself, but their effect is devastating. The good news is, that their effect is not so strong against the Mothership. The most safest way to deal with them is to use the Mothership as diversion (don't forget to equipt it with Tungsteen repair system) and then use your fighters to take out the bombers from behind.