Google earth cannot be installed on Ubuntu 64-bit systems anymore. It requires the ia32-libs which is unfortunately deprecated in Ubuntu 13.10. Luckily I found a solution by mc4man on the Ubuntu Forums. For my own, and perhaps your convenience, I am repeating the instructions here.
Update: for instructions for Ubuntu 14.04, see here.
1) First, make sure you have installed the packages libc6:i386 and lsb-core. You can do this e.g., by typing the following on the command line:
sudo apt-get install libc6:i386 lsb-core
2) If you did not do already, download Google Earth x64 .deb. After downloading, extract the folders and files from the deb package using any unzip program. Easiest is probably to right click on the deb file and in the context menu and select ‘Extract here’.
3) Open the folder google-earth-stable_current_amd64 and than the folder DEBIAN. There you can find the file Control. Open this file in your favourite text editor and remove the line containing: Depends: lsb-core (>= 3.2), ia32-libs. After that save the text file.
4) Delete the downloaded .deb file. Now you have to rebuild the .deb package. Open the terminal and go to the folder that contains the extracted google-earth-stable_current_amd64 folder and run:
dpkg -b google-earth-stable_current_amd64
5) Now you can install the .deb package you just created by double clicking it (that should open the Ubuntu software centre and install it automatically) or by using the following command in your terminal (assuming you are in the folder with the newly created .deb file, otherwise, include the path to the .deb file):
sudo dpkg -i google-earth-stable_current_amd64.deb
Now you should be able to run Google Earth as usual.