A space exploration device from Earth sends back a report of a lower life form. A space exploration device from Earth sends back a report of evidence of prior life with demonstrated intellect from a planet or moon. A space exploration device from Earth sends back a report of an encounter with a non-naturally occurring object. Official organizations report observing craft near Earth. Groups of credible people report seeing occupants of these craft on Earth.
Official organizations acknowledge occupants of craft on Earth.
Groups of credible people report interacting with occupants of craft. Official organizations acknowledge interacting with occupants of craft. Official organizations acknowledge having interacted with occupants of craft over long periods of time. The occupants of the craft demonstrate clear technical and intellectual superiority. The occupants of the craft demonstrate clear technical and intellectual superiority but intent is undeterminable.