Hoagland claims the source of a so-called
NASA "coverup", with relation to the "
Face on Mars" and other related structures, is the result of a report commissioned by
NASA authored by the
Brookings Institution, the so-called
Brookings Report. Hoagland claimed that page 216 of the 1960 report, "Proposed Studies on the Implications of Peaceful Space Activities for Human Affairs", instructed NASA to deliberately withhold from the public any evidence it may find of extraterrestrial activity, specifically on the Moon, Mars, or
Venus. Hoagland has also proposed a form of
physics he calls "hyperdimensional physics", which he claims represents a more complete implementation of
James Clerk Maxwell's original 20
quaternion equations, instead of the original
Maxwell's equations as amended by
Oliver Heaviside commonly taught today. The mainstream physics community rejects these ideas as unfounded. Hoagland claims the "
Face on Mars" is part of a city built on
Cydonia Planitia consisting of colossal
pyramids and mounds arranged in a geometric pattern, indicative of an advanced civilization that once existed on Mars. His book
Dark Mission purports to "carefully document" how "NASA has been quite consciously, deliberately and methodically concealing from the American people and the world for all these years" the "staggering truth ... [that it was not aliens but rather] ...
our own ... ancestors ... who [eons ago] lived ... and built ... and walked amid" that city (emphasis in original) — ditto the Moon. In the years since its discovery, the "Face" has been near-universally accepted as an
optical illusion, Similar optical illusions can be found in the geology of Earth; examples include the
Old Man of the Mountain, the
Pedra da Gávea, and
Stac Levenish. Some astronauts, NASA photo analysts and others have attributed his alleged Moon artifacts to photo processing defects and grainy/fuzzy spots (susceptible to pareidolia) resulting from excessive photo magnification. Although the
Pioneer 10 plaque was designed entirely by
Carl Sagan,
Linda Salzman Sagan, and
Frank Drake, Hoagland has inaccurately claimed to have co-created the plaque with
Eric Burgess, as in 1990 when asserting that "Carl for many years has been taking public credit for the Pioneer plaque which, of course, Eric Burgess and I conceived." Sagan's correspondence regarding the matter also contradicts Hoagland's claims, specifically saying "he did not contribute one bit of data towards the message design." Burgess recalls similarly, adding that all Hoagland did concerning the plaque "was support me and say it's a good idea." ==Responses by scientists==