NASA stated: "One of NASA's key priorities is the search for life elsewhere in the universe, but so far, NASA has not found any credible evidence of extraterrestrial life and there is no evidence that UAPs are extraterrestrial. However, NASA is exploring the solar system and beyond to help us answer fundamental questions, including whether we are alone in the universe."[32]
Response from relevant experts
Joshua Semeter of
NASA's UAP independent study team and professor of electrical and computer engineering with
Boston University's College of Engineering concludes that "without data or material evidence, we are at an impasse on evaluating these claims" and that, "in the long history of claims of extraterrestrial visitors, it is this level of
specificity that always seems to be missing".
[24][25] Adam Frank, a professor of astrophysics at the
University of Rochester, published a critique of the Grusch claims on June 22 with
Big Think. Frank writes that he does "not find these claims exciting at all" because they are all "just hearsay" where "a guy says he knows a guy who knows another guy who heard from a guy that the government has alien spaceships".
[26]
The Guardian printed an opinion piece by
Stuart Clark about Grusch's claims which included questions from three scientists.
Harvard University astronomer
Avi Loeb, who co-founded the UFO-investigating
Galileo Project, noted that nothing extraterrestrial has been observed. Radio astronomer
Michael Garrett noted that crashed landings of alien craft "would imply that there must be hundreds of them coming every day, and astronomers simply don't see them".
Sara Russell, a planetary scientist from the Natural History Museum in London, said that, "if you give me an alloy, it would take me less than half an hour to tell you what elements are in it", and that "it should be easy to understand whether something falling to Earth is man-made or extraterrestrial, and if it is the latter, whether it is naturally occurring or not".[27]
Greg Eghigian, a history professor at
Pennsylvania State University and expert in the history of UFOs as it occurs in the context of public fascination,
[28] notes that there have been many instances over recent decades in the U.S. of people "who previously worked in some kind of federal department" coming forward to make "bombshell allegations" about the truth regarding UFOs with the whistleblower claims by Grusch fitting this pattern.
[29] Eghigian described the 1940s-50s media enthusiasm about
flying saucers, and comments that the successful books on the subject by authors
Donald Keyhoe,
Frank Scully and
Gerald Heard, "provided the model for a new kind of public figure: the crusading whistleblower dedicated to breaking the silence over the alien origins of unidentified flying objects."
[30] Since then all these similarly credentialed claimants have been unable to provide any further corroboration.
[30] Eghigian noted the
All-Domain Anomaly Resolution Office denied all of the claims made by Grusch and he questioned the veracity of Grusch's claims. According to
The Guardian:
https://en.wikipedia.org/wiki/David_Grusch_UFO_whistleblower_claims