Glyth

Glyth was the 6th planet in the Realms' solar system and had long been a bastion of the Illithid.

A ringed planet approximately 1,000,000,000 miles from The Sun. It had 3 sattelites and was one of the Five Wanderers, planetoids that defied the normal rules of orbit. Glyth was a harsh planet, but only because of its inhabitants. What forests they didn't have absolute control over they made sure were burned to the ground to prevent their humanoid cattle from hiding in them. This resulted in smoke filling the atmosphere which, in turn, nearly destroyed the atmospheric envelope and caused the planet to precipitate acidic rain constantly. The smoke caused the entire atmosphere to smell like a charnel house. Of course, this didn't bother the Mind Flayers, who almost universally lived underground.

80% of the surface of Glyth was land while the other 20% was a strange gelatinous substance containing large amounts of water. The substance was edible and quenched thirst just like water would. The substance never turned brackish like normal water, nor did it ever freeze, remaining remarkably pure, despite the awful atmosphere. A sage who investigated the substance noticed that material that touches it is eventually sucked harmlessly right down to the bottom so that the substance is eventually always on top of it. The poles of the planet were covered in regular ice, but, thanks to the smoke, it was dirty.

Glyth's planetary ring orbitted the planet at the equator. During the day it looked like a beautiful, perfectly formed cloud with sharp edges but at night parts of it were coloured in various soft oranges, reds and blues. Sometimes, the ring cast a slight shadow on the planet's surface during the day. From the ground, Glyth's satellites were reported as being attractive-looking as well.

Days were warm and lasted 30 hours and 30 minutes but being on the surface ran the risk of getting hurt by the acidic rain that could burn the flesh of a lot of creatures.

History
Mind Flayer refugees originally came from Glyth to Toril circa -10,700 DR in their Nautiloids and founded the city of Oryndoll.

A sage who was an expert on the Illithid drilled into the ice of one of the poles and recorded that the Mind Flayers living on Glyth at the time had only been there for around a century.

Currently, Glyth is an empty husk. One of the objects in the planet's rings, always thought to be an uninhabitable moonlet, turned out to be Atropus. Atropus was drawn to the planet when a war broke out between the Illithid and a group of rebel cattle. When Atropus got close enough, he annihilated all life he could find before moving on, some say towards Toril.