A planet in the quarian home system of Tikkun.
Adas is marginally warmer than Rannoch despite being further from the sun. Volcanic activity spews methane into its atmosphere, and this haze retains heat in a greenhouse effect.
Historically, the quarians used the geth to mine the planet, and when the geth rebelled, the small quarian population on and around Adas was quickly overrun. The quarians didn't forget this, and upon declaring war on the geth in 2186, they were ruthless in their attack. When Normandy arrived at Tikkun, the remains of geth space stations littered Adas’s orbit, now all shrapnel and fused metal. The Normandy’s sensors picked up a strange croaking sound, probably some kind of distress call from geth survivors left floating in space.
Adas became more prominent with the establishment of the quarian-geth alliance during the Reaper War. As a point of symbolism, Adas was chosen in its aftermath as the site of a joint geth/quarian staging platform called Ilaan Station (translated literally, ‘One Purpose’); though quarian naval presence is miniscule compared to the hundreds of geth vessels that regularly moor and depart from the structure’s considerably advanced docking bays.
There was a Migrant Fleet vessel named the Adasian Sky.