ARISTARCHUS & EULER

14 JUNE 1987

from

04:43 to 8:00 UT.

by

David O. Darling

On the night 13/14  June  11:42 P.M. to 3:00 A.M. local time or 14 June 04:43 to 8:00 UT. Three people witnessed this event and all three of them observed with three different telescopes to rule out instrumental aberration. These three people were members of the Madison Astronomical Society at the time period  this event took place. I am associated with them by also being a member of the same club. I was approached by these three nearly one month after the event happened. They related to me the observation of that night. 

The three observers involved are Keith Curtis, Tom Jacobs and Robert Manske. Keith Curtis took detailed notes of the event as he observed it. The observations were made at the Yanna Research Station, Carl A. Fosmark Jr. Memorial Observatory of the Madison Astronomical Society following the annual picnic. This is MAS dark sky site and is located near Brooklyn, Wisconsin.

As they were observing the night sky they saw the Moon rising and noted a strong orange color due to atmospheric effects. Approximately 1/2 hour after the Moon rise they decided to turn one of the telescopes on it. It was at 04:43 UT, it was noted by Keith Curtis that as the Moon rose it began to loose the horizon color effect and return to its normal color, but he found that the red color was not leaving the crater Aristarchus. At first they all thought this was an atmospheric effect but decided it was a real event since they detected  a second crater (Euler) showing red color on its rim. Keith Curtis said that the red color was very strong on the Western rim of Aristarchus with a strong blue/green or aqua green on the Eastern rim. Keith also reported that the glow opaque enough to prevent viewing of the interior of crater Aristarchus. He said they observed until 3:00 A.M. daylight saving time or 8:00 UT. and the red glow was still visible when they ended  their observing session.

Robert Manske description of the event was that he saw two craters glowing a strong red and blue giving it a rainbow effect. He said that the red glow was so strong he was unable to see the craters underneath during the entire observing session. I asked Robert what the orientation of the red and blue was on the crater. He stated that  he did not remember since he failed to take any notes. I  asked him if he noted any difference in appearance when they observed it with the 17" f4.5 Dobsonian and the 8" f10 SCT Celestron. He said that he could not detect any difference to the lunar formation or the color on it regardless of which telescope he used. He did mention that as the Moon was rising it had the appearance of one large Maria in the center of the disk. This illusion disappeared as the Moon rose higher into the sky.

When talking to Tom Jacobs he said that he remembered that he did not see anything on the Moon until 1/2 hour after Moon rise. He said that he remembered that the entire Aristarchus region had a strong reddish or pinkish color. 

This rendering was done using Reading Information Technology Inc. (RITI) Lunar Map Pro and then using Adobe Photo Workshop to add the colors. The colors are stronger than they appeared in real life but show the appearance and location of the color around Aristarchus with the red on the western rim and the green on the eastern limb and pink all around the crater. One of the observers was not able to see into the interior of the crater as well and reported a faint pink obscured it.

I noted during my questioning of the three witness all reported variations in the type of color they were seeing. This would indicate that individuals color perception is a major factor during a color event. Keith Curtis saw a very strong coloration around the rim of the craters, where Robert Manske saw the entire region covered by this red and blue coloration and he could not see the interior of the craters underneath. Tom Jacobs reported that the glow covered the entire crater but he could see the crater underneath it.

I called the National Weather Service Office at Dane County Airport, located in Madison, Wisconsin. The meteorologist said that nothing unusual was reported that night.

Graph © 2004 by David O. Darling, Director L.T.P. Research

The Moon never achieved a height greater than 21 degrees so it could be that what the observers saw was caused by the Earths atmosphere. It been stated by many a lunar authors that the Moon should be above 50 degrees to eliminate the problem with spurious color.

Graph © 2004 by David O. Darling, Director L.T.P. Research

When examining the date when the Moon passed through perigee it correlates closely with the night of the event. Giving a strong indicator that tidal stress may be a factor for the release of gases deep inside the Moon that is then florescence by the solar plasma.

SOLAR TERRESTRIAL ACTIVITY REPORT

When viewing the data from the Solar Terrestrial Activity Report one finds that low level activity was taking place on the night of the event.