Octopus Overlords

I looked online for an answer, but my google-fu must be weak. When attacking a planet, do all of your allies powers come into play as well as yours?

It's been awhile, but alien powers will state on the bottom of the card (FFG editions, anyway) when they're used in terms such as "main player", "ally", "offense" etc. Some powers can be used in any situation. In Cosmic Encounter terms:

Main Player is either the offense (the player whos turn it is) or the defense (the player who was chosen as the target).
Allies are players who accepted invitations to join either the offense or defense.

For example, the Loser doesn't get use his optional power as an ally because his card reads "main player only". The Macron's power is mandatory and applies when he's a main player or an ally.

This is very helpful, thanks!