How could Cranberry know where New Namek is?

[Benjamin-Simons-91]

(Credit for DuhragonBall from Tumblr who helped me remembering this issue)
It's not like he has been there, or that Moro could sense their ki by using Cranberry's memories of old Planet Namek.

Cranberry was imprisoned for about 17 years after the Frieza Saga, he couldn't know that the Namekians survived and that they live on the planet that became New Namek as even Merus didn't knew where Moro was heading and he is the leading Galactic Patrolman.

Also, Cranberry had no knowledge about the Namekian Dragon Balls requiring their wishes to be granted in the Namekian language, so why did he brought a translator for kidnapped aliens?

[Omori]

Cranberry was imprisoned for about 17 years after the Frieza Saga

It's unknown for how many years Cranberry was on the run hiding from Frieza's army. So technically his imprisonment could be after the Namekians moved to New Namek. But certainly interesting how he got that information.

When he returned back to life on Namek, he probably had like 1-2 minutes to escape with Vegeta's space capsule.
He may have seen Porunga in the distance, but that wouldn't explain him knowing about the wishes in Namekian language and also the amount of 3.

As he kept his scouter intact, he may heard somebody talking about it. Could have been a discussion when Frieza was talking with his father etc. Or who knows what happened while he was on the run.

But true, certainly something which isn't explained.
(hoping for an anime version to bring it up, but not so sure... )

[Magnificent Ponta]

Technically the manga does actually address it; but it's not Cranberry who is implied to know where the Namekians are - Moro is, by virtue of his magical ability to detect life in the wider universe. He's likely helped by the fact that New Namek is apparently the only planet in its general locale with life, which probably made them even easier to detect.

Here's the relevant dialogue from Dragon Ball Super Chapter 44:

Jaco: So where exactly is Moro headed then? There are no planets with life in that direction. What do you think he wants?
Goku: ... No, wait! I've been out that way before!
Vegeta: ! What?! When? What's over there?
Goku: Pretty sure... it was when I went to see Dende.
Vegeta: Dende?! So it's the planet the Namekians moved to?!
Jaco: Start talking! I thought their whole race got wiped out when Namek blew up!
Goku: Nope. We managed to save them all. But for their own safety, nobody's supposed to know where they're living.
Merus: Now that Moro's magic has returned, he's likely capable of scanning for planets with life. And if the Namekians are truly alive, then Moro's goal must be... (etc., etc.)

And, as Pasta's dialogue later in the same scene adds, Cranberry "was looking for someone strong to help him find these balls", which is what piques Moro's interest in the first place. So this scenario doesn't really necessitate Cranberry knowing where New Namek is; arguably that's part of what he's seeking help with. He just knows about the Dragon Balls (and can pilot a ship).

[Mystic-han]

This was already answered in the very same chapter , Moro used his small amount of magic that returned to him to scan and find new Namek