Why didn't the Jedi detect the Death Star? [duplicate]

Question

The Death Star I's construction started on Geonosis since during the Clone Wars. Considering the size of the thing, it must be constructed either in orbit or the surface, since launching it would be too difficult without cracking the planet open like an egg if it's buried too deep. As such, why didn't the Jedi notice any trace of it throughout the war when they've remained in control of the system for most of the war, including the end?

Did it elude the attention of the Jedi and/or clone garrisons? Did it fail to be reported to the Jedi (remember that canon clones aren't in league with Palpatine)? Or was it publicly disguised as a more acceptable project?

Answer 1

First of all, I'd like to clarify - Death Star was NOT built on Geonosis when Jedi were there at the time of AotC, so Jedi couldn't have found it there then. It was only designed there; and the plans of that design were spirited away by Count Dooku precisely so they would not fall into Jedi hands:

Poggle the Lesser: "The Jedi must not find our designs for the Ultimate Weapon. If they find out what we are planning to build, we're doomed."
Count Dooku: "I will take the designs with me to Coruscant. They will be much safer there...with my Master."
(AotC)

It was also not built on Geonosis itself (no matter what you read in an un-cited statement on Wookieepedia), but near it, on a moon and a station called Sentinel Base:

For those in the know, then, it seemed inexplicable that Wilhuff Tarkin should be assigned to a desolate moon in a nameless system in a remote region of the Outer Rim. The closest planets of any note were the desert world Tatooine and equally inhospitable Geonosis, on whose irradiated surface the Clone Wars had begun and which had since become a denied outlier to all but an inner circle of Imperial scientists and engineers.
(James Luceno, "Tarkin")

In addition, it had heavy security. We don't have pre-Tarkin-era details, but under Tarkin:

In the three years Tarkin had been commanding Sentinel and hundreds of nearby supply and sentry outposts, as well as administering a vast slice of the Outer Rim, no group had been successful in penetrating Geonosis space.
(James Luceno, "Tarkin")

_{side note: It was NOT built on Despayre - that was merely in the early drafts of Revenge of the Sith according to Leland Chee)}