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Author Topic: Does the Moon Have an Atmosphere?  (Read 21309 times)

Offline zorgon

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Does the Moon Have an Atmosphere?
« on: June 19, 2012, 12:46:15 pm »
Does the Moon Have an Atmosphere?

In this section we are going to explore this possibility. John Lear has often said and maintains the belief that there is a thin, but tangeble atmosphere on the Lunar surface that is possible to breath for short periods. Though this may be impossible to prove, or believe for some, we shall attempt to gather evidence with this in mind. At the end it is up to the reader to draw their own conclusions...

This idea is not new to John... because in the 1800's several people had already assumed this and John has covered that in his "Civilization on the Moon" thread. I will touch on that here as well

According to NASA....
Lunar Atmosphere Data Sheet


Diurnal temperature range: >100 K to <400 K  (roughly -250 F to +250 F)
Total mass of atmosphere:  ~25,000 kg
Surface pressure (night): 3 x 10-15 bar  (2 x 10-12 torr)
Abundance at surface: 2 x 105 particles/cm3

Estimated Composition (particles per cubic cm):
    Helium 4 (4He) - 40,000 ; Neon 20 (20Ne) - 40,000 ; Hydrogen (H2) - 35,000
    Argon 40 (40Ar) - 30,000 ; Neon 22 (22Ne) - 5,000 ; Argon 36 (36Ar) - 2,000
    Methane - 1000 ; Ammonia - 1000 ; Carbon Dioxide (CO2) - 1000
    Trace Oxygen (O+), Aluminum (Al+), Silicon (Si+)
    Possible Phosphorus (P+), Sodium (Na+), Magnesium (Mg+)

Composition of the tenuous lunar atmosphere is poorly known and variable, these are estimates of the upper limits of the nighttime ambient atmosphere composition.  Daytime levels were difficult to measure due to heating and outgassing of Apollo surface experiments.

SOURCE: NASA Lunar Fact Sheet

So Right from the start we get that cleared up and can see that YES there is an atmosphere, albeit tenuous according to NASA's data.

Offline zorgon

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Re: Does the Moon Have an Atmosphere?
« Reply #1 on: June 19, 2012, 12:49:14 pm »
Cloud Above the Crater Alphonsus

Excerpt

Quote
For years scientists believed there was no trace of gas or an atmosphere on the moon. Now there is some evidence of an atmosphere, though it may be almost too thin to measure. During an occultation of the Crab nebula, astronomers using a radio telescope at Cambridge University detected a slight bending of the rays of the nebula. This deflection could have been due to a thin lunar atmosphere.

In 1956 observers reported what appeared to be a cloud above the crater Alphonsus. In 1958 a Soviet astronomer, Nikolai A. Kozyrev, announced an apparent eruption from the crater. He took spectrograms, which indicated the presence of rarefied gases. His findings caused a revival of debates on the volcanic versus the meteoric origin of moon craters. Many scientists believed that Kozyrev had seen not a true volcanic eruption but a puff of gas and dust from below the surface, probably caused by heat. Some small craters within Alphonsus have “black halos” believed to be deposits of material that have filled the rills along which they are located.

Source Encyclopedia Britanica - Article-204895

UPDATE

This reference is no longer at that link...

Using the Wayback Machine of Archives on that url gets me this...

We're sorry, access to http://student.britannica.com/comptons/article-204895/moon  has been blocked by the site owner via robots.txt.

Offline zorgon

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Re: Does the Moon Have an Atmosphere?
« Reply #2 on: June 19, 2012, 12:54:26 pm »
Lunar Weather Report: 1946

Clear today, no chance of rain or lightning storms.....


LICKOBS9

Extreme weather warning... Hurricane Endymion moving in... 


LICKOBSA Lick Observatory, 1946 January 17d 07h 51m UT

The two images above are clips from two Lick Observatory photographs taken days apart in 1946. The large black crater is Endymion... the clips are located at the 1 O'Clock position on the original images which are available below. As you can see the second image is obscured by a cloud of some form, that covers a large area

Atmosphere: Extensive and of High Scientific Interest

Quote
Though the Moon is surrounded by a vacuum higher than is usually created in laboratories on Earth, its atmosphere is extensive and of high scientific interest. During the two-week daytime period, atoms and molecules are ejected by a variety of processes from the lunar surface, ionized by the solar wind, and then driven by electromagnetic effects as a collisionless plasma. The position of the Moon in its orbit determines the behaviour of the atmosphere...

In addition to the near-surface gases and the extensive sodium-potassium cloud detected around the Moon (see the section Effects of impacts and volcanism below), a small amount of dust circulates within a few metres of the lunar surface. This is believed to be suspended electrostatically...

Source Encyclopedia Britanica - Article-54205

Plume of Vapor or Dust





This "small" Plume or Cloud is very interesting as it clearly shows billowing cloud like effect and seems to be rising from the surface. This is made evident by the "topping off" effect. Is this caused by reaching the upper limit of the atmosphere? A jet stream like effect? A lunar wind? There is no absolute way to know at this time, but the cloud speaks for itself

Offline zorgon

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Re: Does the Moon Have an Atmosphere?
« Reply #3 on: June 19, 2012, 12:58:02 pm »
Is the Moon Still Alive?

Quote
Nasa Science News Nov. 9, 2006:

Conventional wisdom says the Moon is dead. Conventional wisdom may be wrong.

The site is a strange-looking geological feature named "Ina" in Lacus Felicitatis, a lake of ancient, hardened lava located at lunar coordinates 19o N, 5o E. "Ina was first noticed by Apollo astronauts," says Schultz. Pictured below, "it's shaped like a letter D about two kilometers wide."
 



Evidence about Ina points to recent activity:

Quote
Ina is bright and has odd colors. Rocks and dirt on the surface of the Moon grow darker as time passes. The darkening agent is space weather: a nonstop rain of cosmic rays, solar radiation and meteoroids hit the Moon and darken the ground. (The mechanisms are too detailed to discuss here, but the effect is mostly uncontroversial.) Ina, however, is bright, as if fresh dirt has been overturned and newly exposed. Furthermore, the colors of Ina, measured by a spectrometer on the Clementine spacecraft, are similar to the colors of the Moon's youngest craters. Yet Ina is not an impact crater.


A false-color composite photo of Ina and a nearby young crater. Blue denotes freshly exposed titanium basalts, while green traces immature (relatively unweathered) soils.

Quote
It all adds up to outgassing: "We believe there has been a rapid release of gasses, blowing off surface deposits and exposing less weathered materials," explains Schultz. This is not necessarily a sign of active volcanism. "The appearance of the surface at Ina does not indicate an explosive release of magma, which would create visible rays of ejecta surrounding a central crater." Instead, the gasses may have been trapped below ground for millions or billions of years and released by, say, a recent moonquake. This interpretation is appealing because Ina is located at the intersection of two linear valleys or rilles -- like many geologically active areas on Earth.

"Over the years," he adds, "amateur astronomers have reported puffs or flashes of light coming from the Moon's surface." While many professional astronomers insisted the moon was inactive, the amateur sightings kept open a window of doubt.

SOURCE: NASA News Nov 9, 2006

Offline zorgon

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Re: Does the Moon Have an Atmosphere?
« Reply #4 on: June 19, 2012, 01:01:21 pm »
Transient Phenomena

Snippits...

Blasts of gas from deep beneath the lunar surface are giving the Moon a surprisingly fresh-faced look, suggests a new study...

While the current study did not search for gas emissions, NASA's recent Lunar Prospector mission did find small amounts of radon and polonium gas on the Moon’s surface. These are thought to accompany larger volumes of other gases, such as carbon dioxide, that are often associated with volcanic activity...

If the gas turns out to contain hydrogen, methane or water vapour, she says it could be used for fuel or drinking water on future lunar bases...


Quote
To date, the closest researchers have come to examining intact lunar bedrock was in 1972, when members of NASA's Apollo 17 mission drilled less than 3 metres into the dense soil. The fresh-looking features could provide direct access to the otherwise buried rock layers because the gas is thought to have cleared away between 3 to 5 metres of lunar soil in a depression that already had a thin layer of soil.

“Understanding this interface between lunar soil and bedrock will be important for mining and habitation if we ever get to that point,” Taylor says.

The findings could also explain mysterious changes in the brightness and colour of patches of the lunar surface that have been observed for centuries.

Outgassing could cause some of these so-called "transient lunar phenomena", say the researchers. But they add that falling rocks and debris and impacts from space rocks could also account for some of the observations.

Until the bare spots are investigated further, their discovery seems to raise more questions than answers. “It makes us wonder what our nearest neighbour is all about and what other secrets are waiting to be discovered,” Pieters says.

SOURCE: New Scientist news service 08 November 2006

Offline zorgon

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Re: Does the Moon Have an Atmosphere?
« Reply #5 on: June 19, 2012, 01:03:48 pm »
Russian Scientist says Planets' Atmospheres are Changing

Earth's moon is growing an atmosphere Also, the moon is growing an atmosphere that's made up of a compound Dmitriev refers to as ''Natrium.'' Dmitriev says that, around the moon, there is this 6,000- kilometre- deep layer of Natrium that wasn't there before. And we're having this kind of change in Earth's atmosphere in the upper levels, where HO gas is forming that wasn't there before; it simply did not exist in the quantity that it does now. It's not related to global warming and it's not related to CFCs or fluorocarbon emissions or any of that stuff. It's just showing up.

SOURCE
RUSSIAN SCIENTIST SAYS THE SOLAR SYSTEM IS MOVING INTO A NEW ENERGY "ZONE" THAT IS TRANSFORMING THE MAGNETIC FIELDS OF THE PLANETS.  - Wayback Machine Archives

Offline zorgon

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Re: Does the Moon Have an Atmosphere?
« Reply #6 on: June 19, 2012, 01:06:57 pm »
Moon's Extended Sodium Atmosphere


The outer limits of the lunar sodium exosphere.

Quote
A new wide-angle coronagraphic-type imaging system used for the lunar eclipse of 16 July 2000 resulted in detections of the lunar sodium exosphere out to 20 lunar radii, approximately twice the size recorded with narrower fields of view during previous eclipses.

SOURCE: Boston University
The outer limits of the lunar sodium exosphere
- [PDF][Archived][/b][/color]

Offline zorgon

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Re: Does the Moon Have an Atmosphere?
« Reply #7 on: June 19, 2012, 01:11:28 pm »
The Corona Effect - Dust on the Horizon


Moon and Venus - Courtesy of NASA/JPL













The above photos were taken by the NAVY Clementine satellite

Offline zorgon

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Re: Does the Moon Have an Atmosphere?
« Reply #8 on: June 19, 2012, 01:12:46 pm »
CLEMENTINE LIMB GLOW SHOTS
SEARCH FOR HORIZON DUST
BY DAVID O. DARLING


Quote
The following four photographs were taken by Clementine Star Tracker camera. The spacecraft was located on the shadowed side of the lunar disk and was able to take some amazing shots of the Solar Corona. None of these photographs give any indication limb glow due to dust illumination. The overpowering brightness of the Solar Corona flood the picture obliterating any faint illuminations that may be visible.

Depending on what Clementine images you view, you can see dust streamers extending off the limb of the Moon. The images displayed show this phenomena, The other group of shots that show the same lunar limb but is over powered by the intense brightness of the solar corona. See Corona. Other examples of the limb glows or horizon glows can be found at these two sites: Dust and Zodiacal lights (see below)

Close examination of the photograph below give strong indications of dust along the lunar limb. You can see along the entire edge of the disk regions that appearance knotted and swirled faint luminescence.


LBA5881Z Clementine Star Tracker Camera (N.A.S.A.)

Quote
This photograph continued decline of solar illumination but you can still see the faint glowing cloud along the entire edge of the lunar disk.


LBA5883Z Clementine Star Tracker Camera (N.A.S.A.)

Quote
With this photograph you can still see that the illumination along the lunar disk still remain in an illuminated state. The glowing area is most prominent along the mid section of the lunar limb.


LBA5884Z Clementine Star Tracker Camera (N.A.S.A.)

Quote
The final photograph shows that the illumination along the limb continues to glow faintly along the entire lunar limb.


LBA5885Z Clementine Star Tracker Camera (N.A.S.A.)

Quote
"This Startracker image shows the Moon eclipsing the Sun. The bright crescent Earth is partially visible at left, saturating the sensor. The image was captured during orbit 164, on March 26, 1994, halfway through Moon mapping at a distance of 3500 km."

This image of the Moon's limb very well defined but again it is over saturated by the intensity of the solar corona.


STA 552 Clementine Image (N.A.S.A.)


This pre sunrise Startracker image shows the solar corona, stars in the background, and the terminator between the dark side of the Moon and the area on the right, which is illuminated by light reflected from the Earth.


Startracker image showing earthshine portion of Moon with planet Venus at top of picture. The solar corona and solar spike is very evident in this shot.


The color-enhanced image of Venus, the solar corona, and the Moon was acquired by the Startracker. The terminator between the dark side of the Moon and the Earth-lit side can be seen also.


« Last Edit: June 19, 2012, 01:38:47 pm by zorgon »

Offline zorgon

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Re: Does the Moon Have an Atmosphere?
« Reply #9 on: June 19, 2012, 01:18:35 pm »
Clouds In Crater - Apollo Image


Apollo 8 ~ AS8-13-2225

Full Size AS8-13-2225

View of Goclenius and other craters.
December 24, 1968

Just another typical morning on the Lunar Surface.... Sun coming up burning off the morning mist... I wonder what's hiding beneath those clouds...


Image Credit: NASA Click for larger image



Areas of Interest



« Last Edit: June 19, 2012, 01:25:01 pm by zorgon »

Offline zorgon

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Re: Does the Moon Have an Atmosphere?
« Reply #10 on: June 19, 2012, 01:43:20 pm »
Impact Dust Cloud
Smart 1 Impact Raises Dust Plume


Recently the ESA Lunar Probe Smart 1 impacted on the Lunar surface, raising a plume of dust high into the atmosphere... Atmosphere?

The event was captured on film by several sources and does indeed clearly show a plume of dust, and both NASA and ESA call it a "plume", despite what we have been told about the density of the atmosphere. {Note: NASA has NEVER stated that there is NO atmosphere}


Courtesy of ESA/CFHT. (Click on image for hires version) ID number: SEM3353VRRE

This mosaic was built with infrared images taken by the Canada-France-Hawaii Telescope (CFHT) 3 September 2006, and shows the flash and the dust cloud that followed the SMART-1 impact. The 15 exposures that make up the mosaic start with the one taken at the time of the flash.



Quote
"Analysis of images obtained at the CFHT by Christian Veillet have revealed a plume of debris thrown up when SMART-1 impacted the lunar surface."

Image Source: ESA

SMART-1 Impact Flash And Debris:
Crash Scene Investigation On The Moon



Image Credit: ESA

Quote
What happened? Dust after the flash

To determine what part of the flash comes from the lunar rock heated at impact or from the volatile substances released by the probe, it is important to obtain measurements in several optical and infrared wavelengths, in addition to the CFHT observations (2.12 microns).

From a detailed analysis of the CFHT infrared movie of the variations after the flash, a cloud of ejected material or debris travelling some 80 kilometres in about 130 seconds has been detected by observer Christian Veillet, Principal Investigator for the SMART-1 impact observations at CFHT.

SOURCE and More Details - Science Daily
« Last Edit: June 19, 2012, 01:47:53 pm by zorgon »

Offline zorgon

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Re: Does the Moon Have an Atmosphere?
« Reply #11 on: June 19, 2012, 02:00:10 pm »
The Lunar Sodium Atmosphere:
A Study as Observed Through Four Lunar Eclipses


Title:
 The Lunar Sodium Atmosphere: A Study as Observed Through Four Lunar Eclipses
Authors:
 Morrill, A. L.; Mendillo, M.; Baumgardner, J.
Affiliation:
 AA(Boston University), AB(Boston University), AC(Boston University)
Publication:
 American Astronomical Society, DPS meeting #29, #13.10; Bulletin of the American Astronomical Society, Vol. 29, p.987
Publication Date:
 07/1997
Origin:
 AAS
Abstract Copyright:
 (c) 1997: American Astronomical Society
Bibliographic Code:
 1997DPS....29.1310M

Abstract

The Moon's sodium atmosphere has been imaged during four lunar eclipses: November 29, 1993, April 2, 1996, September 27, 1996, and March 24, 1997, using a coronagraph type system at the Boston University four inch telescope located at the McDonald Observatory, TX, and at La Palma, Canary Islands. The Moon is imaged with a 5893A filter with a FWHP of 16A to include the sodium D1 and D2 lines. The eclipse condition provides the opportunity to observe the faint lunar atmosphere when the bright disk of the Moon is within the umbra and penumbra greatly reducing the scattered light in the system. In all four cases, the sodium atmosphere was imaged out to radial distances of 10 lunar radii. The brightness patterns were essentially uniform in azimuth and exhibited a radial decay far more gradual than seen at sub-solar radial distances at quarter Moon. While some variability appears among the four data sets, the large scale morphology under eclipse conditions was remarkably constant during the 1993 to 1997 events. This implies a steady source of sodium at times of full Moon.

Smithsonian Reports - [Abstract Only]

Observational Test for the Solar Wind Sputtering Origin of the Moon’s Extended Sodium Atmosphere - [PDF][Archived]

Discovery of the distant lunar sodium tail and its enhancement following the Leonid Meteor Shower of 1998 - [Abstract Only]

The Lunar Atmosphere: History, Status, Current Problems, and Context - [PDF][Archived]

Offline zorgon

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Re: Does the Moon Have an Atmosphere?
« Reply #12 on: June 19, 2012, 02:04:45 pm »
True Color of the Lunar Sky


Copernicus Crater

Alan Bean describes the Lunar Sky...

"...as black as a pair of black patent leather shoes!"

The color we used in the image above came from a color chart that John sent to Howard Menger... he picked the color as he remembered it to be when he was taken to the Moon...




The Color of the Lunar Sky
An Opinion by John Lear

Offline zorgon

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Re: Does the Moon Have an Atmosphere?
« Reply #13 on: June 19, 2012, 02:13:09 pm »
Moon Fountains

Good old NASA... we can always count on them for a good yarn  ;D

NASA has known for decades about the dust clouds on the Moon, because THEY kept a record of TLP sightings recorded back as far as 1540!!  :o

That's right.. and the results are available in a large file that track all sightings of clouds vapors and mysterious lights appearing

Transient Lunar Phenomena (TLP)
NASA Technical Report TR R-277. was published in July 1968 as a Chronological Catalog of Reported Lunar Events and is available here;
NASA Technical Report TR R-277 - Chronological Catalog of Reported Lunar Events From 1540 to 1966

Moon Fountains



No the above photo is NOT on the Moon, it is an October sunset, Clearwater Beach, Florida.

What it is showing us is "crepuscular rays" or "twilight rays" Those require an atmosphere with dust particles to produce....

NASA Space Science
Moon Fountains
March 30, 2005


Quote
In the early 1960s before Apollo 11, several early Surveyor spacecraft that soft-landed on the Moon returned photographs showing an unmistakable twilight glow low over the lunar horizon persisting after the sun had set. Moreover, the distant horizon between land and sky did not look razor-sharp, as would have been expected in a vacuum where there was no atmospheric haze.

But most amazing of all, Apollo 17 astronauts orbiting the Moon in 1972 repeatedly saw and sketched what they variously called "bands," "streamers" or "twilight rays" for about 10 seconds before lunar sunrise or lunar sunset. Such rays were also reported by astronauts aboard Apollo 8, 10, and 15.


Above: On the left are lunar "twilight rays" sketched by Apollo 17 astronauts;
on the right are terrestrial crepuscular rays photographed by author Trudy E. Bell.


Quote
Here on Earth we see something similar: crepuscular rays. These are shafts of light and shadow cast by mountain ridges at sunrise or sunset. We see the shafts when they pass through dusty air. Perhaps the Moon's "twilight rays" are caused, likewise, by mountain shadows passing through levitating moondust. Many planetary scientists in the 1970s thought so, and some of them wrote papers to that effect (see the "more information" box at the end of this story for references).

But without an atmosphere, how could dust hover far above the Moon's surface? Even if temporarily kicked up by, say, a meteorite impact, wouldn't dust particles rapidly settle back onto the ground?

Well, no--at least not according to the "dynamic fountain model" for lunar dust recently proposed by Timothy J. Stubbs, Richard R. Vondrak, and William M. Farrell of the Laboratory for Extraterrestrial Physics at NASA's Goddard Space Flight Center.

"The Moon seems to have a tenuous atmosphere of moving dust particles," Stubbs explains. "We use the word 'fountain' to evoke the idea of a drinking fountain: the arc of water coming out of the spout looks static, but we know the water molecules are in motion." In the same way, individual bits of moondust are constantly leaping up from and falling back to the Moon's surface, giving rise to a "dust atmosphere" that looks static but is composed of dust particles in constant motion. 


Apollo 17 Sketch

Quote
On the Moon, there is no rubbing. The dust is electrostatically charged by the Sun in two different ways: by sunlight itself and by charged particles flowing out from the Sun (the solar wind).

On the daylit side of the Moon, solar ultraviolet and X-ray radiation is so energetic that it knocks electrons out of atoms and molecules in the lunar soil. Positive charges build up until the tiniest particles of lunar dust (measuring 1 micron and smaller) are repelled from the surface and lofted anywhere from meters to kilometers high, with the smallest particles reaching the highest altitudes, Stubbs explains. Eventually they fall back toward the surface where the process is repeated over and over again.

If that's what happens on the day side of the Moon, the natural question then becomes, what happens on the night side? The dust there, Stubbs believes, is negatively charged. This charge comes from electrons in the solar wind, which flows around the Moon onto the night side. Indeed, the fountain model suggests that the night side would charge up to higher voltages than the day side, possibly launching dust particles to higher velocities and altitudes.

Day side: positive. Night side: negative. What, then, happens at the Moon's terminator--the moving line of sunrise or sunset between day and night?

There could be "significant horizontal electric fields forming between the day and night areas, so there might be horizontal dust transport," Stubbs speculates. "Dust would get sucked across the terminator sideways." Because the biggest flows would involve microscopic particles too small to see with the naked eye, an astronaut would not notice dust speeding past. Still, if he or she were on the Moon's dark side alert for lunar sunrise, the astronaut "might see a weird, shifting glow extending along the horizon, almost like a dancing curtain of light." Such a display might resemble pale auroras on Earth.

Astronauts need to know, because in the years ahead NASA plans to send people back to the Moon, and deep dark craters are places where they might find pockets of frozen water--a crucial resource for any colony.

Will they also encounter swarms of electric dust?

Credits:
Author: Trudy E. Bell

NASA Science Reports - Rest of Article - Moon Fountains

Audio File: Moon Fountains MP3
« Last Edit: June 19, 2012, 02:22:21 pm by zorgon »

Offline zorgon

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Re: Does the Moon Have an Atmosphere?
« Reply #14 on: June 19, 2012, 02:30:58 pm »
What I want to know is WHY did the Astronauts not take a PHOTO of these rays with that handy Hassleblad color camera strapped to their chest. I would thing it would have taken less time that making a sketch and been more dramatic...

But NASA did have photos... much earlier, though we only heard about them with this article released in 2005...

Horizon Dust Glows
The Following images were taken by Surveyor 7
Provided by David Darling



Courtesy NASA/JPL
Illumination along western horizon approximately 15 minutes after local sunset.



Courtesy NASA/JPL
Illumination along western horizon approximately 90 minutes after local sunset.



Courtesy NASA/JPL
Same field of view of western horizon about 160 minutes after local sunset.


Surveyor Observations of Lunar Horizon-Glow

J. J. Rennilson1 and D. R. Criswell2
(1)  Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, Calif., USA
(2)  The Lunar Science Institute, Houston, Tex., USA

Received: 13 August 1973
Abstract  Each of the Surveyor 7, 6, and 5 spacecraft observed a line of light along its western lunar horizon following local sunset. It has been suggested that this horizon-glow (HG) is sunlight, which is forward-scattered by dust grains (~ 10µ in diam, ~ 50 grains cm–2) present in a tenuous cloud formed temporarily (lap 3 h duration) just above sharp sunlight/shadow boundaries in the terminator zone. Electrically charged grains could be levitated into the cloud by intense electrostatic fields (> 500 V cm–1) extending across the sunlight/shadow boundaries. Detailed analysis of the HG absolute luminance, temporal decay, and morphology confirm the cloud model. The levitation mechanism must eject 107 more particles per unit time into the cloud than could micro meteorites. Electrostatic transport is probably the dominant local transport mechanism of lunar surface fines.
This work was supported in part by the California Institute of Technology under Grant NGR 05-002-158, and in part by the Lunar Science Institute, which is operated by the Universities Space Research Association under Contract No. NSR-09-051-001 with the National Aeronautics and Space Administration. This paper is Lunar Science Institute Contribution No. 163.

Surveyor Observations of Lunar Horizon-Glow - [PDF][Archived][/b][/color]

If the direct link doesn't work for you... CLICK HERE

Surveyor 7 was the first probe to detect the faint glow on the lunar horizon after dark that is now thought to be light reflected from electrostatically levitated moon dust.

 


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