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Aristarchus Crater - A Closer Look

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Aristarchus Crater - A Closer Look

Post  Jackie (Admin) on Thu Aug 04, 2011 2:38 pm

The following information is taken from this website:

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Image Info:
LROC Wide Angle Camera (WAC) mosaic of 40 km diameter Aristarchus (23.7°N, 312.6°E). Stratified blocks are presently only observed in the northeast portion of the crater. View the full-sized image release at NASA/GSFC/Arizona State University

Image from:

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Aristarchus Crater

Aristarchus Crater has long been a much debated enigma on the Moon. Yet whenever you see pictures and try to get close in for details, the area is a total white out, with no detail. It is supposedly because of its brightness.

Report Nov 2-3, 1958

"On the night of November 2-3, 1958, Russian astronomer Nikolai A. Kozyrev witnessed a strange phenomenon while making spectrograms of the crater Alphonsus with the Crimean Astrophysical Observatory's 50-inch reflector. As he watched through the telescope's guiding eyepiece, he saw the crater's central peak blur and turn an unusual reddish color. The spectrograms confirmed his visual impressions of a volcanic event; they showed an emission spectrum of carbon vapor (S&T:February, 1959, page 184).. Kozyrev has recorded via spectrograms numerous incidents of red transient lunar phenomena, particularly in the 80 mile wide crater known as Alphonsus. It was at this location in 1965 that the final Ranger probe 9 crash landed. Aristarchus is not only one of the brightest formations on the moon, it is responsible for more than half the number of reported TLP and has been a proven source for gaseous emissions -

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Image Notes:
Aristarchus Crater
Date: 17th December, 2005 ,22:34
Location: Rhodes, North Manchester
Telescope: 8" LX90 SCT
Camera: Philips ToUcam 2xBarlow
Image: 120 Stacked Frames
Processing Software: Registax 3 & Paintshop Pro 8
Image By: Anthony Jennings
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Reports 1650 to 1950

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

1650 Aristarchus "Red Hill." Mons Porphyrites Hevelius B.A.A. Lunar Sec. Circa. 1967, 2, No 8

1784 Aristarchus Nebulous bright spot of light Schroter Schroter 1791
1785 Aristarchus Nebulous bright spot of light Schroter Schroter 1791
1786 Dec 24 Aristarchus Extraordinarily bright Schroter Schroter 1791
1787 May 19-20 Aristarchus Extraordinarily bright von Bruhl Bode 1790; Schroter 1791; Herschel 1912
1788 Apr 9 Aristarchus; 1 hr Extraordinarily bright Bode Bode 1792b
1788 Apr 9-11 Aristarchus Bright spot 26" N of crater rim Schroter, Bode Schroter 1789, 1791, 1792a, 1792b
1788 Sep 26 Near Aristarchus; 30 min Bright spot 26" N of main crater Schroter Rozier 1788, 1792; Schroter 1791
1788 Dec 2, 5:35 am Aristarchus Extraordinarily bright, like star Schroter Schroter 1791

1824 May 1 Near Aristarchus Blinking light, 9th to 10th mag.. on dark side Gobel Gobel 1826
1824 Oct 18 Aristarchus, vicinity Mingling of all kinds of colors in small spots in the W and NW of Aristarchus Gruithuisen Gruithuisen 1824; Fauth 1899
1825 Apr 22 Aristarchus and vicinity Periodic illumination Argelander, Gobel Argelander 1826, Gobel 1826
1866 Jun 10 Aristarchus Star like light Tempel Denning, Tel.Work p.121
1866 Jun 14-16 Aristarchus, vicinity Reddish yellow Tempel Tempel 1867
1866 Dark side Bright spots Hodgson Hodgson 1866
1867 Apr 9, 19h30m - 21h00m Aristarchus, vicinity; 1 hr 30 min Bright spot on dark side, 7th mag., becoming fainter after 20h15m UT Elger Elger 1868
1867 Apr 12, 07h30m - 08h30m Aristarchus, vicinity; 1 hr Bright spot on dark side, 7th mag.. Elger Webb 1962
1867 May 6-7 Aristarchus; at least several hours each night Left side of crater, very bright luminous point, appearing like a volcano Flammarion Flammarion 1884
1867 May 7 Aristarchus, vicinity Reddish yellow, beacon like light Tempel Tempel 1867; Astr. Reg. 1868
1884 Nov 29, 19h00m - 21h00m Aristarchus; 2 hr Nebulous at center; elsewhere features well defined Hislop Sirius 1885
1889 Jul 12, ~20h52m Aristarchus During lunar eclipse, brilliance in surrounding gloom was striking Krueger Krueger 1889; Fisher 1924
1891 May 23, ~18h20m Aristarchus region Lunar eclipse, half hour before end of totality, Aristarchus and region immediately N of it became conspicuous and increased in brightness from that time on W.E. Jackson Jackson 1890-91; Fisher 1924

1931 Aristarchus Bluish glare Goodacre, Molesworth Goodacre 1931
1949 Oct 7, ~02h54m Aristarchus Abnormally bright during lunar eclipse G.Brown, Hare Contrib. by Moore
1949 Nov 3, 01h06m Aristarchus Blue glare, base inner W wall Bartlett Bartlett 1967

1950 Jun 27, 02h30m Aristarchus Blue glare, base inner W wall Bartlett Bartlett 1967
1950 Jun 27 Herodotus Bright point in crater Bartlett Strol. Astr. 1962
1950 Jun 28, 03h27m Aristarchus Blue glare, rim of W wall Bartlett Bartlett 1967
1950 Jun 29, 05h30m Aristarchus Strong bluish glare; E, SE wall Bartlett Bartlett 1967
1950 Jul 26, 02h52m Aristarchus Blue glare, base inner W wall Bartlett Bartlett 1967
1950 Jul 31, 04h50m Aristarchus Violet glare, E, NE rim Bartlett Bartlett 1967
1950 Aug 28, 04h25m Aristarchus Intense blue violet glare; E wall bright spot, E, NE rim Bartlett Bartlett 1967

Author(s): Cameron, W. S.
Abstract: This catalog lists 1468 descriptions of observed lunar transient phenomena reported in the literature.
NASA Center: Goddard Space Flight Center
Publication Year: 1978
Added to NTRS: 2005-08-25
Accession Number: 78N30157; Document ID: 19780022214;
Report Number: NASA-TM-79399, NSSDC WDC-A-R S-78-03

NASA Lunar transient phenomena catalog

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Apollo 11 Transcript from Mission Debriefing Log

Here is the actual transcript as well as the source:

7.17 Orbit Parameters for LOI-2

Postburn NOUN 44 was 54.4 by 66.1.

Did you want to talk about that orbit being targeted 55 by 65 rather than 67?

Yes, I think we made it clear on a number of occasions preflight that we were not in agreement with the change, just prior to flight, to the 55 by 65 orbit. We did not disagree with the intent of what they were trying to achieve; it's just that this did not have the benefit of its effect on a number of other areas of the flight plan. I still feel as though that was somewhat of a mistake. There were some other sides to the discussion that had not been fully reviewed by all the parties.

What about items between the two maneuvers?

One item that came up was the request to look at the crater Aristarchus to see if we could see any glow or evidence of some observations that had been made by people on the ground. That does bring to mind that as we were coming in on LOI and I could see the edge of the Moon coming back into the daylight, it appeared to me that at one point (which I can't identify) there was one particular area along the horizon that was lit up. I doubt that it was anywhere near Aristarchus. There appeared to be one region that was a little unusual in its lighting. Maybe our films will catch that. We'll just have to try to identify that one when we see the pictures. I don't think that there is any particular connection, but I thought I'd mention it because it did strike me as a little unusual.

As long as we're talking about Aristarchus, I'd agree with Buzz's observation that the brightest part of the area that was somewhat illuminated might agree with the zero phase point of earthshine. This would mean you're getting a lot of local reflection from earthshine. That certainly –

You talking about once we were in lunar orbit?

Yes. I would certainly agree, particularly with the highly illuminated parts of the inside of the crater wall. I think it was also true that the area around Aristarchus, that is in the plains, was also more illuminated.

It wasn't just the crater, it was the whole general area.

It's not necessarily obvious that this also would happen to agree with the zero phase point of earthshine.

It could. We had nothing to compare it with.

This was not in sunlight; it was in earthshine. That wouldn't have been zero ...

Offhand, it doesn't agree with anything I can think of, and it seemed to extend for quite a distance around that area. Although I called that a fluorescence, it's probably not a very good term. It certainly did not have any colors that I could associate it with. There was just a higher local illumination level over the surface at that point.

I was a brighter area than anything else we could see in either direction. I don't know if you could compare that with any of the brighter areas we saw in the sunlit portions – say on the back side; it didn't look like it was the same thing at all. Not having anything to compare it with in the way of earthshine illumination, we really couldn't tell much.

We could say the effect was there, and it was a very pronounced effect. It's a more obvious effect than looking the Earth's zodiacal light. It's a more pronounced effect than zodiacal light which is also observed easily with the eye. Our post-LOI-2 P52 option 3 was a good one with an extremely low torquing angle (torqued at 81.05). After this, we prepared the tunnel for LM ingress.

Let's go back to the first time we went into the darkness on the front side, in higher orbit before LOI-2. This was before we got to the region of the landing site. It wasn't illuminated at that point. I guess it's a question of your eyes being light-adapted to the lighter things that you are looking at that are in sunlight. The contrast when going into the terminator was very vivid. There was just nothing to be seen, yet you would wait a short while and then you'd pick up earthshine, and you could see quite well. As soon as the sunlit portion of the Moon disappeared from your eyes, you could get dark adapted. Then we could start looking at things like Aristarchus. There was as much earthshine on the dark side of the terminator as there was later on, but your eyes could just not adapt to it, and it was just pitch black. After a short while you would be able to pick up fairly reasonable lighting coming from the Earth. I don't know what you would relate that to, or if you'd say that's at all adequate for any landing operation. I doubt that. It certainly did enable you to make observations.

I think that adequately states it.

We didn't do an extensive amount of observing in earthshine.

I thought it was about 5 to 10 minutes past the terminator before I was really observing things in earthshine very well.

I think earthshine is four or five times as bright as moonshine on the Earth.

I don't remember making the comparison. It was done on previous flights. Some of the people on previous flight thought it might be conceivable to make landings into earthshine. I don't guess I would be willing to go that far yet. It looked like the amount of detail that you could pick up, at least from orbital altitude, wasn't consistent with what you really need in order to do a descent.

You might do things like telescope tracking or even sextant tracking. ... characteristic features in the sextant, though we didn't try to do that.

It's difficult to pick out things in earthshine, unless it's a very pronounced feature like Copernicus, Kepler, or some of the bigger craters. You could see those way out ahead and track them continually. For smaller features that are not well identified with large features close by, I don't think you would be able to pick them up. We are ready for the second hatch removal now. "

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Report April 23, 1994

Sky and Telescope published an article basically saying anyone who sees a TLP is just seeing an illusion, despite hundreds of sightings by reputable astronomers... Well April 23, 1994 would change that dramatically... and involves our friend Clementine

"A satisfying rebuke to the TLP naysayers was recently delivered by JPL's B. Buratti at the October 1999 meeting of the American Astronomical Society in Padua, Italy. Her specific TLP occurred on April 23, 1994. At that time, about one hundred amateur astronomers noticed a 40-minute darkening near the edge of the bright lunar crater Aristarchus. Happily, when this hundred fold "illusion" took place, the lunar satellite Clementine was mapping the area around Aristarchus. Defying the dogmatists, Buratti scrutinized the Clementine data again. Sure enough, Aristarchus had really turned redder after the TLP reported by the amateur astronomers."
- Science Frontiers #127, JAN-FEB 2000. © 1997 William R. Corliss

Report July 19, 1969

Apollo 11 provides us with this incidence that gives a perspective of one event from two angles... one on Earth and one in orbit around the moon.

"On July 19, 1969, the Apollo 11 command module had just achieved orbit around the Moon when the Mission Control Center in Houston, Texas, received word that amateur astronomers reported transient phenomena in the vicinity of the crater Aristarchus. Asked to check out the situation, astronaut Neil Armstrong looked out his window toward the earth lit region and observed an "area that is considerably more illuminated than the surrounding area.
It just has -- seems to have a slight amount of fluorescence to it." Although he wasn't sure, Armstrong believed the region was Aristarchus." -

UPDATE Sept 07, 2007
REPORTS of curious flashes and fleeting clouds on the Moon may not be figments of wild imaginations, astronomers say. A new look at observations by the American satellite Clementine show that a small area on the Moon's surface darkened and reddened in April 1994. Why this happened remains a mystery.

For hundreds of years, people have reported seeing flashes, short-lived clouds and other brief changes on the Moon's surface. But astronomers have never been able to confirm the sightings. "The events were observed on many occasions, but most astronomers don't believe in them," says Bonnie Buratti of NASA's Jet Propulsion Laboratory in Pasadena, California. On 23 April 1994, around a hundred amateur astronomers reported seeing a possible darkening of the Moon, lasting 40 minutes, near the edge of the bright lunar crater Aristarchus. At the same time, the US Department of Defense's Clementine satellite was mapping the lunar surface.

SOURCE: New Scientist


"One of the first real attempts to catalogue a large number of TLP sightings was made on behalf of NASA and published in a report which gave details of 579 mysterious lunar events dating from 26 November 1540 (pre-telescopic) to 19 October 1967 [4]. The catalogue appeared just a year before Neil Armstrong planted his size 11 boot in the Sea of Tranquillity; strange that such an important and well-funded Moon-landing programme chose to arm itself with some basic historical TLP data only at the very last minute.

NASA's belated enquiries represented a grudging acknowledgement that the Moon might not actually be the dead world it so convincingly advertises itself to be for most of the time. It was in NASA's interest, however, to down-play the idea of an active Moon. Known factors in lunar exploration were hazardous enough to plan for and contend with, without having to admit that lurking somewhere beneath the Moon's surface there might be some unknown, unpredictable and uncontrollable threat to their prospective Apollo lunar astronauts which could jeopardize the $25 billion programme. "

SOURCE: Fortean Times FT105 December 1997"Light Side of the Moon"

So, what causes this crater to glow and change color, according to years of observation? Your thoughts and analysis would be welcome!
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Jackie (Admin)

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Join date : 2011-05-13

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