David Grinspoon

The same scientific rationale that supports the possibility of detectable extraterrestrial civilizations elsewhere also supports the plausibility (not likelihood) of extraterrestrial artifacts being found within our own solar system, most of which has not been searched for such artifacts.

the same rationale which supports the idea [that] extraterrestrial civilizations may exist... also supports the idea that finding extraterrestrial artifacts in our own solar system is at least plausible

A panelist states the group has not seen extraordinary evidence of non-human intelligence and that making such a claim would require evidence they do not have.

we have not seen the extraordinary evidence that... would require... to make the claim that we see something that is evidence of, you know, non-human intelligence... and we have not seen that

In the 1990s, NASA scientists believed they had found fossil evidence of past life in a meteorite from Mars; the finding was verified extensively before being announced via a presidential press conference with President Clinton, offered as an institutional precedent for how NASA would handle confirmation of an extraordinary life-related discovery.

a big event actually in the history of astrobiology was in the 1990s when some scientists had thought that they had discovered fossils in a meteorite that came from Mars... there was a big, in fact, presidential press conference with President Clinton