NASA · NASA-UAP-D018
Gemini IV Experiment Debriefing, Airglow Structure and Aurora (1967)
This 224 page file combines Gemini IV (GT-4) mission documentation, an early flight plan and press style description of the mission's scientific experiments, and a degraded transcript of a NASA scientist discussing the visual and airglow results. It is largely experiment and flight plan data rather than UAP material, but it is significant for one reason: it scientifically characterizes the very nighttime "curtain" that McDivitt and White reported (in NASA-UAP-D017) as airglow structure and southern lights, and it restates that Glenn's "fireflies" were airglow plus dust particles. It does not present any McDivitt object as an unexplained craft.
Key excerpts
“McDivitt and White [...] saw a structure in the air g[l]ow and this is the fi[r]st time this i[s] [r]eport[ed]. [...] They observed [meteors] [going] into [the] earth's atmosphere down [b]elow them. [...] over Australia they saw [southern] lights. (lines 1932 to 1957)”
“Really, what Glenn saw wa[s] air[g]low [...] or a luminous l[a]y[er]. There may be a little dust there [...] but the predominate feature is [that] it is a [self] [l]uminous l[a]yer. (lines 1885 to 1891)”
Alternative hypotheses
Airglow structure and aurora australis
the documented explanation, most probable).
Dust and outgassing particles
"fireflies").
An unexplained object
not supported).