Is your computer updated to the last step of Leopard OS X 10.5(.8) and the latest old supported Flash player plugin installed? While the latter may not be necessary, the former most likely would be in order to use the last Google Earth component for a vintage system such as Leopard. My Leopard running Macs use GE 5.2.1 from almost 4 years ago. And I keep them locked so google updater won't change them to an unsupported update.
So define the system, parts, and software in question, with detail; so as to help find suitable reply.
The most recent Google Earth won't work in Leopard 10.5.8. I saved an older version in archive and had to reinstall it when Google Earth automatically updated and I found a newer GE application that was too new to run in my OS X version. So I deleted it, and installed the older saved version, then used Get Info, and clicked the Lock in that window, so the version would not be changed by Google Updates.
If you need a browser and your computer is really a powerPC model with G4 or G5 processor, not an intel Mac, then you may have to go looking for something that works that sees an update once in awhile. Safari doesn't. My older computers still have 4 to 5 browsers, some are no longer updated so may be at risk; I use three mostly, and find TenFourFox is OK. By default flash is disabled. I also use SeaMonkeyPPC but chose an older version that works best in my slow CPU G4s, not the later build claimed to be most secure. And then I have iCab, it runs free but would work best with a purchased license.
My three computers that run Leopard 10.5.8 can use Google Earth, Streetview, and so on. You may have to use Google Maps if streetview won't work in a Google Earth version (perhaps version 6, one of the last that could work in a PowerPC Mac system.) I believe all my Macs have the same GE version that runs in 10.5.8, and I locked it so it won't update.
https://www.google.com/#q=Google+Earth+for+Mac+10.5
Only one of mine is an intel-based Mac, the other two are powerPC G4. The intel-based Mac can use an older Firefox, but sees no new version update. There is a Seamonkey for intel mac that is not available through the PPC version page, so I have a few odd browsers with similar names.
But Safari in these see no current support or security updates.
Not sure if this helps, but it may.
Good luck & happy computing! 🙂
