Unlike many other Google logos, Google Earth's logos don't include any text at all.
Google Earth started development in 2001. Its initial release was on June 11, 2001.
During 2015-2017 it was still being used as a secondary logo.
This logo first appeared on the Android 5.0 Lollipop Google Earth app. The non-3D version is shown at the full list of Google Apps. The non-3D version also sports a different white points and a slightly different blue used for the lines.
This logo first appeared as the app icon in the revamped Google Earth on April 18th.