From Ubuntu GNOME 14.04.5, I installed gnome-maps from trusty-proposed. gnome-maps displays its maps (both street and satellite) ok now. (Note that gnome-maps in trusty is affected by bug 1274433 which requires a reboot or something after the initial install of gnome-maps. I don't think upgrades are affected.)
From Ubuntu GNOME 14.04.5, I installed gnome-maps from trusty-proposed. gnome-maps displays its maps (both street and satellite) ok now. (Note that gnome-maps in trusty is affected by bug 1274433 which requires a reboot or something after the initial install of gnome-maps. I don't think upgrades are affected.)