Cosmic Abyss is the 3rd layer of the Cyber Galaxy mine in Mining Simulator 2. This layer of the mine begins when you reach a depth of 659. The layer continues until a depth of 1,090.
You can access a free chest in the Cosmic Abyss lobby. This chest rewards some space tokens based on your multiplier & respawns every 1.5 hours. Reset it instantly for 99 Robux.
There is also an egg that you can hatch in this layer called the Nebula Egg.