STAR CHART: PLANETS -
PLANETARY CLASSIFICATION - Y

Class-Y planets, sometimes called by way of a nickname Demon-Class worlds, are extremely inhospitable to humanoids. Surface temperatures can exceed 500 kelvins, with toxic atmospheres filled with thermionic radiation. It can be dangerous for a spaceship even to orbit a Class-Y planet. This information is provided in [#92 Demon].

In 2374, USS Voyager visits a Class-Y planet and there encounters a mimetic lifeform. With the crew's agreement, the mimetic lifeform takes on the forms of the Voyager crew. These events are depicted in [#92 Demon]. Janeway: "Captain's log, supplemental. I've ordered adaptations to our shields to repel the thermionic discharges. Hoping that the benefits will outweigh the risks, we're now trying to beam deuterium from beneath the planet's surface." The picture shows Voyager orbiting the Demon class planet.

[#112 Course: Oblivion]

These 'silver blood' duplicates also take on the memories of the Voyager crew and set out in their own Starship Voyager on a quest for Earth in the Alpha Quadrant. The latter part of their adventures, which occur in 2375, is portrayed in [#112 Course: Oblivion]. Duplicate Tuvok: "Ten months, eleven days ago. Voyager was forced to land on a Class-Y planetoid in the Vaskan sector."

[#112 Course: Oblivion]

Later the duplicate ship and crew arrive at a Class-Y planet - it is seen on the Bridge's viewscreen - but they are not permitted to land there.

Ha'Dara on a stolen Hirogen ship's monitor display [#155 and #156 Flesh And Blood]

In [#155 and #156 Flesh And Blood], hologram Iden plans to settle himself and his holo-followers on a planet to escape the Hirogen. Doctor: "It's Y-Class - toxic atmosphere, sulphuric deserts, no trees, no life at all." Iden: "You're still thinking like an organic. We don't need an atmosphere. We don't need water. What we need us protection from our enemies."