I wanna say bungie themselves stated the 7 destinations number. I wanna say besides the 4 you mentioned The Rift and Mercury are confirmed, I think the 7th is still unknown.
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As per the wiki it looks like seven destinations: http://destiny.wikia.com/wiki/Category:Locations
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Lol wiki
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Where was this said by Bungie
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Saturn perhaps? Since there was mention of that much earlier on (which means it'll likely be added in one of the future expansions, but very unlikely in the initial release...)
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I believe it was titan, a moon that was mentioned before, but not heard much since... Hmm?
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Saturn sounds great from the rumours. The zone is allegedly an armada of deserted spacecraft in orbit.
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I think you mean The Reef
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Where?
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