You can install Google Earth Pro to auto-update. Download Google Earth Pro for desktop If you need to manually update Google Earth, you can download the most recent 6.2 and 7.x direct installers. read more
Google Earth has received an imagery update recently, with the new imagery showing up in ‘historical imagery’ in the last couple of days. Until recently the most recent image was from November 30th, 2015, and now the most recent image is from January 11th, 2016. read more
If you want to see where Google Earth (and Google Maps) imagery was last updated either check out the Google Earth Blog for update announcements or simply click on the 'Google Earth Imagery Updates' link below to see the highlighted areas on the globe. read more
Finally, the databases cannot be updated until a new version of Google Earth is released which happens every few months. Thus, it takes more time. On average, imagery of an area is updated every 1-3 years. read more