Was Google Earth purchased by another company, or vice versa?

No. The mapping software was originally developed by Keyhole Inc. company which Google acquired in 2004 and further developed the software as Google Earth.

https://en.wikipedia.org/wiki/Keyhole,_Inc

No. Google Earth is still very much Google's. What eventually became Google Earth was at first EarthViewer 3D by Keyhole Inc.

yep I just bought it.

No. Google Earth was developed by Google (as far as I know).