Lunar impacts tonight?

[igorsboss]

I was outside just now (12:25 AM to 12:31 AM PDT) looking at the moon. The polution is so thick tonight that the moon looks as red as it would in a total lunar eclipse.<br /><br />As I was observing, I observed several pinpoint flashes of light appearing at several places on the lunar surface with the naked eye.<br /><br />They were pinpoint dots of orange light, each lasting from 2 to 5 seconds. I observed about 3 to 5 of them.<br /><br />So, I said "wow", and ran for my binoculars to see if I could observe any more. I saw one more faint one in the binoculars. My wife asked "can I see?", so I handed the binoculars to her. She observed one.<br /><br />All the lights were tiny unmoving pinpoints, like a star, not extended objects in any way. All the lights occurred on the lit side of the moon. <br /><br />I don't know if they were real or illusions. The moon is setting for me now. Can anyone confirm?

 

[igorsboss]

If what I was seeing was real, not some optical illusion, I think my wife and I just witnessed one of two things:<br /><br />1) A lunar meteorite shower.<br /><br />2) Fallout from a single earlier, larger impact.<br /><br />I don't know who else to contact or how to confirm. The moon has set for me now.

 

[igorsboss]

The lights looked a bit like sparkles on the lunar surface, like sparkles on sand or snow. All were points of light. None exhibited proper motion. Each started bright, and faded over time.<br /><br />As I was watching, I had the impression that there were many (tens) of other sparkles that were very faint and quick, beyond my ability to map or confirm.<br /><br />I didn't see any sparkles on the dark side of the moon, or in the dark space around the moon. All of them were on the lit side of the moon.<br /><br />The fact that I didn't see any sparkles on the dark side makes me wonder if these sparkles were an artifact of the heavy pollution.<br /><br />I drew a sketch of the position, and so did my wife. I haven't attempted to correlate any of these with a lunar map yet.<br /><br />My position is in Mill Creek, WA. The sketch was made so that my local horizon is at the bottom, as observed. To communicate the position of the sparkles, I'll use polar coordinates, with zero degrees at the leftmost edge, with the moon as unit circle (radius = 1.)<br /><br />The brightest spark was at theta=30, r=.6, duration = 5 seconds. Bright orange, the color of hot coals. It was the first one I took notice of.<br /><br />Then I saw about 2 or 3 other bright ones which I did not map or take note of. My binoculars were very handy at the time, so I grabbed them.<br /><br />I observed was through binoculars (Canon 15x45 IS 4.5degrees UD), handheld, using image stabilization powered by new batteries. The image stabilization in these binoculars yields exceptional visual clarity. In one test, I was sitting in the passenger seat of a car on the freeway, at freeway speed, and was able to read the licence plate of a car about 50 yards away.<br /><br />The last one I observed was at theta = 240, r=.4, duration = 2 to 3 seconds, through binoculars. Orange again, but dimmer.<br /><br />Then I handed the binoculars to my wife. She drew a sketch also. It was at theta = 20, r = 1.0, duration = 250 millis

 

[igorsboss]

<font color="yellow">I'll use polar coordinates, with zero degrees at the leftmost edge</font><br /><br />Correction: rightmost edge. oops.<br /><br />(The locus of the polar function theta = 0 is a line parallel to my local horizon.)

 

[yruc]

The Apollo astronauts did place large reflectors on the moon that are used to measure how far away the moon moves from earth each year (about 1.5 inches a year). Could be you happened to catch a reflection of the sun off of them... though not sure exactly how large the reflectors are or if its possible.

 

[igorsboss]

I think those reflectors are designed to reflect light back directly to the observer, using 3 mirrors positioned at right angles.<br /><br />You are correct that they did seem like reflections from the surface.<br /><br />However, I observed several of them, and each of them were hundreds or thousands of miles apart from each other. Completely facinating.

 

[igorsboss]

I sent some email to Brian Cudnik and got this reply:<br /><br /><font color="yellow">Thanks for the information...I will post this on the IOTA occultations listserver, and the lunarimpacts list server. I will also have this posted on the Lunar Transient Phenomena listserv as we were expecting some 60 individuals to participate in last night's watch. However, the down side is that your events took place after most of them likely packed it up for the night, but we shall see.<br /><br />Too early to tell, of course, but a cluster of meteoroids seems to fit the picture, assuming these were real impacts and not some terrestrial phenomena (I cannot think of any terrestrial phenomena that would mimick this unless you overlook the near-impossible odds of the phenomena occuring in such as way as to produce the observed effects...).<br /><br />Thanks for the report, and any additional, detailed information, especially time of events, would be helpful.<br /><br />Brian Cudnik<br />ALPO Lunar Meteoritic Impact Search program<br /></font>/safety_wrapper>

 

[silylene old]

There was a very good article on reliable visual observations of meteor strikes on the moon (including a video) in Sky and Telescope 2 or 3 yrs ago. Perhaps someone can find a link. <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[igorsboss]

And then I sent Brian this reply email. I'm quoting myself for the rest of this post...<br /><br />I don't have super-accurate timing information for you, but I did look at the clock, which read 12:31AM, when I came back in from the observations. The observations took place on July 28th, 2004 between 12:25 AM and 12:31 AM PDT, in Mill Creek, Washington, zip code 98012. I'm guessing the first observation was closer to 12:28AM. I just calibrated that clock against the naval observatory... My clock was about 12 seconds fast.<br /><br />The observations took place on my back deck as the moon set. I had gone outside to check on the hot-tub, then spotted the moon setting. It was a very deep orange color, like in a lunar eclipse. I've photographed several lunar eclipses before, so I'm familiar with what the moon looks like in eclipse... I've never seen anything like this before.<br /><br />I called my wife out to see the deep color of the moon as it set. She had seen the sun set earlier that evening, and told me that it was so extremely red that she could look right at it at sunset. I was staring directly at the moon at that moment when I saw the first spark. It was definately a tiny pinpoint of light. I could hardly believe my eyes!<br /><br />The brightest point was about as bright as one of the brightest stars, but not as bright as Jupiter or Venus. I did not observe scintilation. My best guess at the visual magnitude would be about M0, plus or minus one magnitude. It was brighter than the lunar surface, but was a point source. The brightness is very difficult to judge, because of the deep pollution, and the fact that I was observing this against the moon's bright surface.<br /><br />If anyone else was watching this with sensitive photographic equipment, they would definately have been able to detect the event. I didn't have time to set up any equipment before the moon set.<br /><br />From this experience, I would recommend the use of deep orange filters for this k

 

[robnissen]

"why would the meteor shower be confined to the moon? Would not the Earth have intercepted the meteor stream as well?. . . so why would the Earth not have had widespread reports of an unexpected shower as well."<br /><br />I don't think it was an "unexpected shower?" According to this article there are numerous small meteor showers beginning July 17th leading up to the big Perseid shower in the second week of August.<br /><br />http://www.space.com/spacewatch/040723_perseid_preview.html<br /><br />My guess is that you saw a few of these meteors hit the moon, and that you didn't notice the ones hitting earth's atmosphere because 1) these are small meteor showers, on average about one/minute; and 2) the meteors may have been washed out by the light of the moon, which you were looking straight at; and 3) I think, although I am not sure, that it is more difficult to see meteors on the horizon than overhead, obviously, if there was a minor meteor shower it was at the horizon because the moon was setting.

 

[igorsboss]

The first step to confirming this is reporting it.<br /><br />I would love to see this confirmed, but I'm not too sure that it is going to happen.<br /><br />I got super lucky because of the smoggy sky, because it allowed naked eye observations.<br /><br />Since I live on the west coast and the observations happened at moon set for me, confirmation could not have come from midwest observers - the moon would have set for them. Perhaps confirmation might come from a Hawaiian observer.

 

[igorsboss]

Was this really <font color="yellow">an unexpected shower</font><br /><br />From the ALPO Lunar Section Meteoritic Impacts Search web page at http://www.lpl.arizona.edu/~rhill/alpo/lunarstuff/lunimpacts.html#Definitions<br /><br />Under "Upcoming Opportunities", I found this paragraph:<br /><br /><font color="yellow">There are two opportunities approaching later this month and next for the observations of lunar meteors. The first is with the lesser shower, the Southern Delta Aquarids, on 27 July 2004. The Terrestrial peak of this broad and weak stream is 18:35 UT and the Moon sets 8.3 hrs after sunset. Earth-based ZHR = 20, with 38% impacts on unlit near side, polar graze angle of -8 degrees. This one is a challenge, since the Moon is in waxing gibbous phase, about 75% illuminated, with much reflected sunlight and only a small crescent of dark lunar disk.</font><br /><br />My observation came just a few hours after the predicted Terrestrial peak noted above.