eh? Several plot points of the episode point to the detention center and Tandar Prime being two different planets.

GRAT [on viewscreen]: ...If you stay on course for Tandar Prime I'll arrange for an ambassador to show you our capital city when you arrive.
REED: (later) I've isolated their carrier frequency. Do you see it?
HOSHI: I'm tracing it now. Bearing one seven eight mark twelve.
TUCKER: How far?
REED: Five point two light years.
TUCKER: All I'm saying is we go take a look for ourselves, make sure they're okay.
T'POL: Proceed.

If they were on course for Tandar Prime already, tracing Grat's transmission and changing course would seem rather silly. - AJ Halliwell 06:11, 19 February 2007 (UTC)

Yes, they are definitely two different places. That's why the moon we seen in "Detained" is located here. --Jörg 14:45, 19 February 2007 (UTC)
That's because AJ added it there yesterday after he left this comment. ;) --Alan del Beccio 17:10, 19 February 2007 (UTC)