Ool was a terrestrial planet in the Unknown Regions located in the Chiss Ascendancy. In 18 BBY, it was inhabited by over two billion Chiss residents and was a fairly popular destination for tourists. Ool's landscape consisted of beaches and mountains, and it was also a farming world with a rich and diverse agricultural base and large and small manufactory groups. Mining operations took place in its mountain spines, including in one of the Ascendancy's three pure nyix metal mines. The city of Pomprey was located on Ool, where a skybus depot was found.
The Ardok Ranch was located in the "wilds of Ool," which belonged to Cohbo'rik'ardok, core name "Borika," and her husband, Bomarmo. The Ardok Ranch was also home to the Seekers' Shadehouse, a facility of the Seekers program that worked with sky-walker navigators. In 18 BBY, Chiss Expansionary Defense Fleet caregiver Mitth'ali'astov, core name "Thalias," once visited the ranch to speak to Borika about problems her sky-walker, Che'ri, was having. They spoke about the sky-walker's training process, but Thalias was soon called away to the planet Csilla. She returned to Ool some weeks later, accompanied by Che'ri so the Shadehouse could learn from her problems.
Ool was a terrestrial planet in the Chiss Ascendancy, located in the Unknown Regions of the galaxy, and was breathable for the Chiss species. Ool was an agricultural world and also had various mountains and beaches across the planet. The farms held a few non-sentient domesticated animals, such as packbull. Mining took place on Ool, where veins of the nyix metal could be found. The planet housed one of the Ascendancy's three pure nyix mines.
Caregiver Mitth'ali'astov traveled from Csilla (pictured) to Ool.
In 18 BBY, on the Ascendancy planet Naporar, Mitth family Senior Aide Mitth'iv'iklo, core name "Thivik," handed Chiss Expansionary Defense Fleet caregiver Mitth'ali'astov "Thalias," a former sky-walker navigator, a data cylinder that was compiled by Syndic Mitth'ras'safis, core name "Thrass," before the Syndic's death. The data cylinder contained information on Ool and the Seekers' Shadehouse—a facility of the Seekers program that worked with sky-walker navigators who had special abilities known as Third Sight that allowed them to guide Chiss ships through the space outside Ascendancy borders known as the Chaos.
Soon after, Thalias took leave from her duties while the warship on which she served—the Chiss heavy cruiser Springhawk—underwent repairs at a bluedock over the Ascendancy capital planet Csilla to travel to Ool. The Springhawks first officer, Mid Captain Ufsa'mak'ro, core name "Samakro," informed Thalias that Ool was a day and a half's flight from Csilla.
Thalias arrived on Ool looking for the Shadehouse, which was absent from all the guidebooks she had looked through. The caregiver eventually made her way to the Ardok Ranch, located at the address she had been provided with on Thrass' data cylinder. She was greeted by Cohbo'rik'ardok, core name "Borika," who owned the ranch alongside her husband, Bomarmo. As Borika was involved with the Seekers program, she and the caregiver spoke about Che'ri, who was the sky-walker Thalias took care of, and the problems she was having. Thalias began to question the sky-walker's training, which Borika did not entertain and suggested that Thalias could stay at an inn in the nearby city of Pomprey while waiting for an answer.
Borika was the owner of the Ardok Ranch and the sister of Senior Captain Thrawn (pictured).
Eventually, Borika revealed that part of the sky-walker training involved the removal of the young girls' memories so that they would not remember their families and, therefore, not leave the program. As both women were former sky-walkers, that led to the discussion of Borika's erased memories—Thrass' data cylinder revealed that she was the sister of Senior Captain Mitth'raw'nuruodo, core name "Thrawn," who was the commanding officer of the Springhawk. Shortly after, Thalias was called back to Csilla, and Borika took her to the Ibbian Spaceport to catch a transport back to the capital.
Some weeks later, Thalias returned to Ool, this time accompanied by Che'ri, as the girl had wrapped up her campaign alongside Thrawn. Although she did not want to stay on Ool, she was convinced by both Thalias and Borika to stay as sky-walkers were already rare, and Che'ri's experiences had made her the most unique of them all. Borika informed her that what she told the Seekers program could help her and many sky-walkers to come.
In 18 BBY, the planet was home to over two billion Cheunh-speaking Chiss and was also revered as a prominent destination for tourists and travelers, who enjoyed its beaches and mountain skiing. An agricultural world, it had various farms across the planet to support its rich and diverse cultivation base. Ool also catered to several large manufacturing plants in addition to thousands of smaller ones. As it housed a mine of pure nyix and also exported the metal, extensive mining took place in the spines of Ool's mountains.
Located in the wilds of Ool was the Ardok Ranch, which housed the Seekers' Shadehouse. The Ibbian Spaceport was a spaceport on the planet, situated nearly one thousand kilometers from the ranch. The city of Pomprey was also located on Ool, where a skybus depot and a few hotels could be found.
In the current Star Wars canon, Ool appeared in the 2021 novel Thrawn Ascendancy: Lesser Evil, written by Timothy Zahn as the final volume of Star Wars: The Ascendancy Trilogy. It was pictured simultaneously on a map provided by publisher Del Rey as a bonus for preordering the novel. In the Star Wars Legends continuity, the planet Ool was introduced in the 2009 reference book The Essential Atlas, written by Daniel Wallace and Jason Fry.
