nasa-uap-d5-apollo-17-crew-debriefing-for-science-1973.pdf

CB/R.A. PARKER
MSC-07632
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION

# APOLLO 17 CREW DEBRIEFING FOR SCIENCE

JANUARY 8, 1973

## PREPARED BY SCIENCE REQUIREMENTS BRANCH PLANETARY AND EARTH SCIENCES DIVISION

|  INDEXING DATA | DATE | OPR | # | T | PGM | SUBJECT | SIGNATOR | LOC  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
|   | 1-8-73 | MSC | MSC-07632 | B | AP0 | # | NS | 080-44F  |

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MANNED SPACECRAFT CENTER
HOUSTON, TEXAS

HS1-481238

119

HENRY (CONT'D)

gravitationally holding it together. We though it might be 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 excludes 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 …

120

HENRY (CONT'D)

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.

Fifth point: Lyman-alpha hydrogen radiation is a…