Is there any way to enable public editing of a public Google calendar?

So I succeeded in making my Google calendar public and shared it with my group on Facebook. I want to allow anyone on my Facebook group to edit the Calendar without having to go through the steps of giving them admin privileges.

Is it possible to allow anyone to edit my public Google calendar? If so, how? If not, does a free public calendar application exist out there that allows free for all editing?

Thanks in advance!