NASA-UAP-D5, APOLLO 17 CREW DEBRIEFING FOR SCIENCE, 1973

About this document

NASA-UAP-D5, APOLLO 17 CREW DEBRIEFING FOR SCIENCE, 1973 is a declassified record from the U.S. National Aeronautics and Space Administration, dated , classification DECLASSIFIED. It is part of PURSUE Release 01 — the Pentagon's first public unsealing of UAP records under the Presidential Unsealing & Reporting System for UAP Encounters program, published on 2026-05-08 at war.gov/UFO/. UAP.WATCH has indexed the full text locally so the document can be read, searched, and cited without leaving the site.

Linked incidents

• Lunar Sky, north of Grimaldi crater — 11 DEC 1972 (PURSUE-003)

Document text

  119

HENRY  gravitationally holding it together.  We though it might be
(CONT'D)
  in the form of ionized hydrogen.  We looked for Lyman-alpha

  radiation, red shifted from the ionized hydrogen, and we
  didn't see any.  We set a lower limit, which certainly ex-

  cludes the possibility that the Coma cluster is held together
  by this ionized hydrogen.  I think that may leave a real
  mystery as to what  is holding the thing together.

  The fourth point may turn out to be the most interesting

  thing of all. When you look in the Milky Way, you see a

  lot  of UV coming from the stars, but the question is, what

  do you see when you look up to the North. Galactic Pole or

  down to the South Galactic Pole.  One of the most exciting

  results of X-ray astronomy was the fact that an X-ray back-—

  ground was observed over the sky that nobody had expected,
  and part  of this  is the gamma-ray background that Dr. Trombka

  talked about.  In the  UV, nobody knows, but you never know

  until you look.  You do have to deal with this background

  of stars that we know is there.  So we did look at a large

  number of different points  at high galactic latitudes, both

  north and south. The spectrum that we see is above this
  dark count. In other words , this abnormally high dark
  current did not,  in fact,  interfere with that experiment.

  The spectrum that we see looks like the spectrum of the hot
120

HENRY  star; however, we know that there were no hot stars within
(CONT'D)
  our field of view.  Therefore, the most  conservative inter-

  pretation, I think, is that what we're seeing is light from

  hot stars in the galactic plane going up out of the plane

  and reflecting off interstellar dust.  There are certain

  characteristics of the spectrum, though , that don't fit that

  theory, and it's at least possible that this is extragalactic

  radiation.  I'm looking forward very much to the detailed

  computer study of this, but it's going to take a long time.

  Fifth point:  lLyman-alpha hydrogen radiation is a completely

  separate problem, and Gary Thomas  at the University of

  Colorado and Charles Barthum [7] observed this from O0GO-5.
  We obtained just an enormous amount of data on the Apollo
  that's going to straighten out this picture and clarify it
  considerably.  This  is hydrogen that is  inside our solar

  system.  It's sunlight reflecting off this. The hydrogen,
  Gary Thomas  thinks,  is hydrogen from interstellar space

  streaming through the solar system, and he is looking for-

  ward with great anticipation to getting detailed analyses
  of that.

  One more thing:  the spectrum of the Earth.  I keep saying

  we," but these were the guys that were there.  We looked
  1f.

  at the Earth from outside.  A lot  of people have observed