Apollo 17 Crew Debriefing for Science, 1973

This is the Apollo 17 Crew Debriefing for Science, document MSC-07632, issued by NASA's Manned Spacecraft Center in Houston and dated January 8, 1973. The extracted pages record a scientist named Henry reporting ultraviolet spectrometer results. These include a search for ionized hydrogen in the Coma cluster that found none. They also cover ultraviolet light at high galactic latitudes, possibly reflected by interstellar dust or extragalactic in origin, and Lyman-alpha hydrogen inside the solar system. The pages contain no UFO content.

From the source: Release of 2026-05-08 Apollo 17 was the ninth crewed U.S. mission to the Moon, and the sixth to land Astronauts on the lunar surface. This document is an excerpt from the Apollo 17 Crew Debriefing for Science on January 8, 1973, in which Dick Henry, co-investigator on the ultraviolet experiment on Apollo 17, discusses seeing results that were unexpected. • Pages 119-120. “One of the most exciting results of X-ray astronomy was the fact that an X-ray background 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 star; however, we know that there were no hot stars within our field of view. Therefore, the most conservative interpretation, 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.”

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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: Lyman-alpha hydrogen radiation is a completely
separate problem, and Gary Thomas at the University of
Colorado and Charles Barthum [?] observed this from OGO-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?
at the Earth from outside. A lot of people have observed
"