In Earth science, a shapeless cloud of gas and dust is called a nebula.

Here's a bit more about them:

* Composition: Nebulas are primarily made up of hydrogen and helium, along with small amounts of heavier elements like oxygen, carbon, nitrogen, and iron.

* Formation: They form when massive stars reach the end of their lives and explode as supernovas, scattering their material into space.

* Evolution: Nebulae can evolve into stars, planetary systems, or remain as diffuse clouds.

* Examples: Some famous nebulae include the Orion Nebula, the Eagle Nebula, and the Crab Nebula.

Let me know if you'd like to learn more about a specific aspect of nebulae!