DISCLOSURE / FILE
Excerpt from the Apollo 17 Crew Debriefing for Science (January 8, 1973) in which co-investigator Dick Henry reports an unexplained ultraviolet spectrum observed at high galactic latitudes that resembles hot-star light yet has no hot stars in the field of view.
NASA-UAP-D5, Apollo 17 Crew Debriefing for Science, 1973
Excerpt from the Apollo 17 Crew Debriefing for Science (January 8, 1973) in which co-investigator Dick Henry reports an unexplained ultraviolet spectrum observed at high galactic latitudes that resembles hot-star light yet has no hot stars in the field of view.
On January 8, 1973, NASA's Manned Spacecraft Center recorded the Apollo 17 Crew Debriefing for Science (MSC-07632). Dick Henry, co-investigator on the ultraviolet experiment, told the panel that pointings toward the North and South Galactic Poles produced a UV spectrum above the dark count that looked like a hot-star spectrum even though no hot stars sat within the field of view. Henry's conservative reading is reflected hot-star light off interstellar dust, but he flagged spectral features that do not fit that theory and said extragalactic radiation remains possible. He told the panel a detailed computer study would be needed and that it would take a long time.
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.p.2
In the UV, nobody knows, but you never know until you look.p.2
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.p.2
The spectrum that we see looks like the spectrum of the hotp.2
star; however, we know that there were no hot stars within (CONT'D) our field of view.p.3
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.p.3
I'm looking forward very much to the detailed computer study of this, but it's going to take a long time.p.3
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....................... Cg_, ,_,,_,,_,,Z'_ iiiiiiii!i!i!i!i!iiiill ..... M S C -07 632 :i: >> ................ iiiii!iiiiiiiii!iiiiiii "_APOLLO 17 ililiiiiiiili!ii!iiiii!::::::::::: CRE W DEBRiEFING i iiiiiiiiiiiiiiiiiiiiiii FOR-SCiENC °o,i°t°o°i°a°I ° o°e°JI° ,°. °° °°.°° ° °°°°°°°°°°°° ° °° ° °°°°%° ::::::::::::::::::::::: ::::::::::::::::::::::: ::::::::::::::::::::::: eoo°°°°i°°e °° o°i°°° - °°°°°°°° ° 'ooi° °°,° ° ° °°° °°° o°, ° ,eoi.,o ,°°°o°°°°°°°°°°I°o°,°° °°°°_°°°°° ° , °***°_ ° _°_* ° ° °,°°_°°°%_°,°°°°',_ iii!iiiiiiiiiiii!i!!i!i >>>>>>>>>>> : JANUARY 8 , 19 7 3 °°°°,°°°°° , ° °° °°°°,° ,%°°,°° ° °°°° ° ::::::::::::::::::::::: ::::::::::::::::::::::: °°° ° °°°°°°. ° °° ° ° °°° ° °°°,°° ° ,°°° °° ° °° ° ,°°°°°°° ° ,° ° ° - ,°°° ° ° ::::::::::::::::::::::: ::::::::::::::::::::::: ::::::::::::::::::::::: ::::::::::::::::::::::: ::::::::::::::::::::::: :::::::::::::::::::::::: PREPAR ED BY PLANETARY ND EARTH SCIENC - ES DI V ISION ..,,.1..°°, ii!iiiiiii!?i!iiiiiiiii !!iii!i!!i!!!!!ii!i!i!! ?!i!i!iiiii!i!i!ii!i?ii iiiiiiiii!!iiiiiiiiiiii ,_,._ATA "( ::::::::::::::::::::::: DATE OPFI # T PG M SUB, IEGT SIGNATOB LOG iiiii!iiiiiiii!ii!iii!i !ii?iiii!i!i?i[ii!i!!i! °°° ..... °° °° 4 ¸i!!¸!¸! ::iiiil i?::! MANNED SPACECRAFT CENTER iii: !i.: _. i::_,_. HOUSTON,TEXAS :i.i:!:ii ::::::::::::::::::::::: ::::::::::::::::::::::: ::::::::::::::::::::::: ::::::::::::::::::::::: ::::::::::::::::::::::: ,.°°°,°° ° °., .......... Hs/ - H _ / ,7_ ;
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ll9 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 J 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
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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 pla n e 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
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....................... Cg_, ,_,,_,,_,,Z'_ iiiiiiii!i!i!i!i!iiiill ..... M S C -07 632 :i: >> ................ iiiii!iiiiiiiii!iiiiiii "_APOLLO 17 ililiiiiiiili!ii!iiiii!::::::::::: CRE W DEBRiEFING i iiiiiiiiiiiiiiiiiiiiiii FOR-SCiENC °o,i°t°o°i°a°I ° o°e°JI° ,°. °° °°.°° ° °°°°°°°°°°°° ° °° ° °°°°%° ::::::::::::::::::::::: ::::::::::::::::::::::: ::::::::::::::::::::::: eoo°°°°i°°e °° o°i°°° - °°°°°°°° ° 'ooi° °°,° ° ° °°° °°° o°, ° ,eoi.,o ,°°°o°°°°°°°°°°I°o°,°° °°°°_°°°°° ° , °***°_ ° _°_* ° ° °,°°_°°°%_°,°°°°',_ iii!iiiiiiiiiiii!i!!i!i >>>>>>>>>>> : JANUARY 8 , 19 7 3 °°°°,°°°°° , ° °° °°°°,° ,%°°,°° ° °°°° ° ::::::::::::::::::::::: ::::::::::::::::::::::: °°° ° °°°°°°. ° °° ° ° °°° ° °°°,°° ° ,°°° °° ° °° ° ,°°°°°°° ° ,° ° ° - ,°°° ° ° ::::::::::::::::::::::: ::::::::::::::::::::::: ::::::::::::::::::::::: ::::::::::::::::::::::: ::::::::::::::::::::::: :::::::::::::::::::::::: PREPAR ED BY PLANETARY ND EARTH SCIENC - ES DI V ISION ..,,.1..°°, ii!iiiiiii!?i!iiiiiiiii !!iii!i!!i!!!!!ii!i!i!! ?!i!i!iiiii!i!i!ii!i?ii iiiiiiiii!!iiiiiiiiiiii ,_,._ATA "( ::::::::::::::::::::::: DATE OPFI # T PG M SUB, IEGT SIGNATOB LOG iiiii!iiiiiiii!ii!iii!i !ii?iiii!i!i?i[ii!i!!i! °°° ..... °° °° 4 ¸i!!¸!¸! ::iiiil i?::! MANNED SPACECRAFT CENTER iii: !i.: _. i::_,_. HOUSTON,TEXAS :i.i:!:ii ::::::::::::::::::::::: ::::::::::::::::::::::: ::::::::::::::::::::::: ::::::::::::::::::::::: ::::::::::::::::::::::: ,.°°°,°° ° °., .......... Hs/ - H _ / ,7_ ;
ll9 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 J 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 pla n e 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