- G-Cloud (Wikipedia)
The Galactic (G) cloud or G cloud, also known as the G-Cloud (or G-Cloud complex) is an interstellar cloud located next to the Local Interstellar Cloud, within the Local Bubble. It is unknown whether the Solar System is embedded in the Local Interstellar Cloud or in the region where the two clouds are interacting, although the Solar System is currently moving towards the G-Cloud. The G-Cloud contains the stars Alpha Centauri (a triple star system that includes Proxima Centauri) and Altair (and possibly others).
- Geological formation (Wikipedia)
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics (lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exposed in a geographical region (the stratigraphic column). It is the fundamental unit of lithostratigraphy, the study of strata or rock layers.