ALPO Lunar Meteoritic Impact Search

Brian Cudnik
Coordinator

Department of Chemistry and Physics

Prairie View A&M University

P.O. Box 519, MS 2230

Prairie View, Texas 77446
mailto:cudnik@sbcglobal.net

This program is designed to standardize and coordinate amateur observations of meteoroid impacts on the Moon. This field has exciting possibilities but only if the observations are done in a uniform manner and pooled to look for confirmations of positive observations. Anyone interested in participating should contact the Coordinator above for further information. The Coordinator maintains an "Impact" e-mailing list of regular participants, e-mail him if you would like to be added to the list. Click here to read the full mission statement.

What's New (02/02/12)?

Lunar Impact Alert Notices

Classic Impact Alert Notices and Updates

Upcoming Observing Opportunities

Lunar Impact Plots (1999-2006) by Peter Gural

Links to Lunar Impact Information

Lunar Impact Alert Notices!

Monitoring Lunar Meteors in 2012 and the LADEE Mission

As of this writing, it appears that our next significant opportunity for lunar meteoroid observations will come with the South Delta Aquariids, which peaks on July 29. The moon is a waxing gibbous that day, having passed First Quarter three days earlier. Through the eyepiece, the Earthshine is still faintly visible at this phase but the sunlit part of the moon gets rather bright for useful monitoring. Nonetheless, this looks like a good challenge to attempt for those of you who like observing challenges.

Our next opportunity comes with the Perseids, just a few weeks later, peaking on August 12^th. This peak happens five days before the moon reaches New, so it is a waning crescent in the predawn sky. We have some opportunity to capture some lunar Perseids during this time, but the area presented to the incoming meteors which is also visible from Earth is rather small. But this should also be worth a try.

We need to wait over two months for the next favorable alignment of the Moon and an annual shower, but this happens with the Orionid meteors which have a broad peak lasting five days centered on October 21. The moon is a thick waxing crescent during this time, reaching First Quarter phase on the 22^nd, so the conditions are excellent to attempt to observe the pointlike flashes of lunar Orionids.

The Leonids, now once again a weak shower, peaks on the 17th of November, with the Moon being a thin waxing crescent four days past new. This should be good for looking for lunar Leonids during the few days prior to, and after, the peak of this meteor shower. Finally, in the opening days of 2013, the Quadrantids peak around the time of last quarter moon, and may be somewhat favorable for impact monitoring (more on this later).

The 2013 Perseids are favorable for lunar observations, and Brian Day of NASA-Ames wants to collaborate with us for this particular shower in support of the LADEE (Lunar Atmosphere and Dust Environment Explorer) mission, scheduled to launch in May of this year, More information about the mission itself can be found at this website: http://www.nasa.gov/mission_pages/LADEE/main/. This mission looks for dust and other goings-on at the moon and one of the objectives is to find out how much dust is kicked up by lunar meteoroid impacts. This, combined with careful measurements of the light curve, and knowing the impact velocity of the meteoroid, will enable us to get an estimate of the luminous efficiency (how much impact energy goes into making the optical flash) of the impact as well as the mass of the impactor (at least roughly).

What follows are the dates of when the moon is a waxing or waning crescent favorably placed for lunar impact observations, either from the sporadic background and/or from the many minor showers that pepper the year. Observers who are able to are encouraged to monitor the moon during the following intervals, which generally run from four days past New to a day or two after First Quarter, then again a day or two before Last Quarter up to about four days prior to New. Traditionally the evening waxing lunar phases have shown more impacts than the predawn waning phases for the same reason we see more meteors in the morning hours than the evening hours. In both cases we / the moon are facing the oncoming meteoroids as each move in their respective paths around the Sun (as the moon is carried along with the Earth...).

Waxing (evening) dates: 27 Jan. to 2 Feb., 24 Feb. to 3 Mar., 25 Mar. to 1 Apr., 24 Apr. to 1 May, 24 May to 30 May, 22 to 29 June, 22 to 28 July, 20 to 26 Aug., 19 to 24 Sept.,18 to 24 Oct., 16 to 22 Nov., 16 to 22 Dec. 2012.

Waning (morning) dates: 15 to 20 Jan., 13 to 18 Feb., 14 to 19 Mar., 12 to 18 Apr., 11 to 18 May, 10 to 16 June, 10 to 16 July, 8 to 14 Aug., 7 to 13 Sept., 7 to 12 Oct., 6 to 10 Nov., 5 to 10 Dec. 2012.

A Likely Impact from a Sporadic Meteoroid

The GLR (Geologic-Lunar Research) group in Italy reported a very likely lunar meteoroid impact candidate on 11 February 2011 at 20:36:58.355UT. The obsevers were Stefano Sposetti and March Iten. Stefano Sposetti reports, “Marco Iten and me detected a probable impact flash on the Moon, simultaneously, from our two observatories, located 16km apart. It lasted about 4 fields (i.e. 0.08s) in one video file; a bit less in the other video file. No artificial satellites were in a 2-deg field of view at the moment of the detection and the two flashes in the two video files are located at the same lunar feature.” Since impact was observed with two telescopes separated by 16km (below the arbitrary 30km threshold that we use to determine uniqueness) and it has been verified that no artificial satellites were in the vicinity of the moon at the time of the impact, this can be considered a confirmed event. More information, including analysis, can be found at this website http://digidownload.libero.it/glrgroup/st22web.htm.

A Confirmed Quadrantid from 2009

Bernd Gährken has reported an impact event, observed by him in Bayrischzell in the Bavarian Alps, and by Otto Farago stationed 250km away in Stuttgart, both in Germany. Mr. Gährken posted the information on this observation at the following website: http://www.astrode.de/1impa3.htm (click on the British flag for translation).

Geminid Meteoroid Impacts on the Moon Observed

So far, aside from the NASA-MSFC program, I know of one confirmed Geminid observation-my own. I have an image, alongside that from NASA showing the impact flash near peak intensity. It is interesting to see the difference in brightness owing to the fact that their instrument was a 14 inch telescope and mine was the 8 inch telescope. Others who may have observed the Geminids are encouraged to check their tapes for the impact events listed below or others not listed. People may also check the NASA Meteoroid office website for more Geminid candidate impact events when they become available.

The moon was well placed in the evening sky for the Geminid meteor shower and we were able to capture some good data. I had clear skies the three nights I videotaped the moon, but prior commitments delayed my start times. The following is a list of lunar Geminid observations made by Robert Spellman and the Meteoroid Environment Group at the NASA Marshall Space Flight center. I video recorded one of their impacts, but the others were made either when I was not set up to observe or they were events too faint to detect conclusively with my setup. The event I recorded occurred on 14 December 2010 at 3:33:38.775 (Time obtained directly off the video frame, it is a timestamp from KIWI-OSD). More candidates will be reported as I receive them.

From Robert Spellman:

13 December 2010 1:28:26UT ±1min

14 December 2010 3:09UT ± 1 min (out of MSFC FOV)

http://www.angelfire.com/space2/robertspellman/geminidflash.html

From NASA-MSFC:

December 13/14

Weather reasonably good with occasional patchy clouds (3 14" telescopes used)

# UT # of frms

1 23:53:51.635 4 Bright

2 01:16:14.634 2 Bright

3 01:16:42.028 2 Bright

4 01:49:31.547 3 Bright

5 01:55:48.120 1 Bright

6 02:51:00.704 1 Moderate Bright

7 02:55:57.598 2 Bright

8 03:33:38.773 3 Bright

9 04:08:31.080 3 Bright

10 04:35:39.761 2 Faint

11 04:43:03.534 1 Moderate Bright

12 04:52:12.078 2 Moderate Bright

Flash 3 has no independent confirmation...Bill Cooke, NASA Meteoroid Environment Office

Another Meteor Videotaped On Jupiter!

Another Jovian meteor was videotaped as it happened at 18:22UT on 20 August 2010. The event was recorded independently by two observers in Japan: Masayuki Tachikawa of Kumamoto city was first to report the event, and Tokyo amateur astronomer Aoki Kazuo made the confirming recording some 800 km away. More information on this event, including pictures and video, can be seen on the August 23, 2010 page of www.spaceweather.com. Sky & Telescope also has a story on this which can be read at http://www.skyandtelescope.com/observing/home/101264994.html.

This makes the second confirmed meteor observation on Jupiter in 2-1/2 months, with the first being on June 3^rd. The June 3 and 4 page of www.spaceweather.com has more information, including an image and a video of this extraterrestrial meteor, which occurred at 20:31 UT on June 3^rd. You can also go to the news section of Astronomy Magazine’s website (http://www.astronomy.com/asy/default.aspx?c=ss&id=26, scroll to the archives near the bottom of the page, select June 2010 and look for the link…) to get the news story. Amateur astronomers Christopher Go (the Philippines) and Anthony Wesley (Australia) simultaneously observed this event, making it the first ground-based confirmed observation of an actual impact event on another world beside the moon (to my knowledge). The impactor must have been a rather large object to have produced such a bright flash of light as seen from a half billion miles away.

The first meteor did not produce any dark markings, and it is unlikely that this one will do so as well. Both appear to be atmospheric fireballs that disintegrated before reaching the clouds.

This reinforces my suggestion (which is now being considered by others) to begin a serious project of continuously monitoring of Jupiter for impact events. This would need to be done at high powers, enough for 1 arc-second (or better) resolution. A setup similar to what is used in lunar meteor or asteroid occultation work, but with larger telescopes (at least 10-inch) and less sensitive cameras (since Jupiter is bright) would do the trick, and could reveal the true rate of such impacts with implications for Earth and the impact probability here.

Opportunities to Observe Lunar (and Jovian) Meteor Impacts!

Aside from sporadic, the next opportunity lies with the Alpha Aurigid meteor shower (trickle) with a ZHR of 6 on September 1. The moon is a very thin crescent which may not be favorably placed to observe until at least August 2^nd. After this come some decent opportunities with the Orionids in October and (what’s left of ) the Leonids in November. I have made available the working list of meteor showers for 2011, courtesy of International Meteor Organization, which can be obtained by clicking here. The moon has been unfavorably placed for most of the major showers this year. For the Orionids and the Leonids, the moon is near or just past last quarter which is not as favorable as the waxing moon prior to first quarter, but many lunar meteors have been observed during the predawn hours.

While the Moon may not be too exciting in this area, Jupiter is certainly becoming a more interesting target for meteoritic studies. Those who are able to are encouraged to monitor the planet for signs of atmospheric fireballs as often as possible, and now that the planet is less than one month from opposition, the view could hardly be better.

Observers are also requested to monitor the moon for up to 10 nights per month in support of the NASA-MSFC effort to regularly patrol the moon, from a waxing crescent of 10% illumination to the first quarter (50% illuminated) phase and again from last quarter to near new moon. Current estimates predict up to 260 impacts per month of objects of 1 kg or greater on the lunar surface, many of which can be captured with ground-based equipment. Thus, it is important to observe the moon as much as possible in order to refine these estimates, which will become even more useful since NASA plans to send astronauts back to the moon by 2020. The LMIS is coordinating monthly campaigns for 2010. The dates of each campaign, both routine and related to annual meteor showers, are now posted here.

More Lunar Impact Observations!

Robert Spellman, Griffith Observatory Telescope Operator, reported a Lunar Orionid impact candidate that he has recorded: “I recorded a flash on 2 frames, the best time I could get was 2:08:45 UT 10/22/2009. This is very uncertain due to very poor radio reception from station WWV. My Boss Tony Cook was observing visually from Griffith Observatory using a 4" refractor and may have seen the flash (see below). The flash appeared to be just north of Mare Serenatatis. I was using 2 recorders the first directly into the computer via video capture software and a DVD recorder. The DVD recorder was in the long play mode so the image recorded on only one frame. The video capture via the computer shows the flash on 2 frames, the images are somewhat darker due to an error in setting the brightness.” Images and information about this and other impacts that Mr. Spellman has observed can be seen at http://www.angelfire.com/space2/robertspellman/.

In October 2009, LRO reported seeing a faint plume in images over-exposing the bright part, enabling the faint plume to be recorded. From the ground, nothing was seen, based on numerous reports from ground-based observers using instruments which ranged from 8 inches on up to the 200 inch Hale telescope, with adaptive optics, at Palomar Observatory in California, USA. NASA-TV did not show any obvious impact phenomena except for a faint flash, and the warm infrared afterglow of the fresh crater. Apparently the spacecraft impacted relatively soft terrain, resulting in the faint flash and a lack of a prominent plume of material. Information about this mission, including any new findings, can be found at http://lcross.arc.nasa.gov/. And yet more images and information can be found at http://lcross.arc.nasa.gov/observation.htm.

Lunar Meteoroid Impacts and How to Observe Them!

The book is now available for purchase at bookstores as well as online. One can go to Springer’s website and find more information about the book, at http://www.springer.com/astronomy/book/978-1-4419-0323-5. One can also go to Amazon.com and get it for as little as $17.56 (used) off the publisher price; the website is (it looks truncated so if this link does not work, simply go to www. amazon.com and type in the title of the book in the search field, and it will come up)…

http://www.amazon.com/s/ref=nb_ss_0_10?url=search-alias%3Daps&field-keywords=lunar+meteoroid+impacts+and+how+to+observe+them&sprefix=Lunar+Mete

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Further impact observations reported in 2009 and 2010 are provided next:

A confirmed lunar meteor impact was spotted by George Varros at 01:45:26UT on April 28, 2009. This was a sporadic meteoroid, too dim for LunarScan to pick up, but spotted upon close visual inspection of the videotape after a call for a confirmation by the MSFC group. Their remote telescope was experiencing cloudy weather rendering it unavailable for a remote confirmation. This underscores the importance of mutually supportive observations to provide backup and confirmation of events that may be detected by one party, but missed by a second due to weather. A third party would then have the potential to make the confirming observation. For more information on this and other such surprises, visit http://www.lunarimpacts.com/lunarimpacts.htm.

One impact candidate from the recent Quadrantid stream has been reported by Mr. George Varros. The event occurred at 0:26UT 3 January 2009 and more information can be found at http://www.gvarros.com/002622_curve.jpg. Mr. Varros and I videotaped the Moon again between 23:30UT, January 3 and 2:45UT, January 4, but no impact candidates were observed during this interval.

NASA-MSFC effort now has 222 impact candidates (as of November 2, 2010, plus the 12 reported Geminid impact candidates from 13 December 2010). The dates, times, selenographic coordinates, and source (sporadic or shower) are included in the table on their home page (link below). Observers are encouraged to carefully check their videotapes near these dates/times for corroborating impact signatures. Please visit http://www.nasa.gov/centers/marshall/news/lunarupload/index.html for information on these impact candidates. The number of impacts recorded by this group serves as a reminder that these events are happening on a regular basis and is a motivator for individuals to keep up the observations in support of this and lunar meteor work in general. The locations of the candidates on the lunar surface can be viewed on the above link.

LunarScan 1.5 by Peter Gural now Available!

The latest version of the automated detection software is ready for download. Go to http://www.lunarimpacts.com/lunarscan15.zip to download a copy. This version is usable for formats up to 720x576 (PAL). The software is free under the condition that you provide impact flash observations (date/time/location) to NASA's Meteoroid Environment Office at the e-mail address listed under "Contact Us" at http://www.nasa.gov/centers/marshall/news/lunarupload/index.html.

A “Quick Start” guide to LunarScan can be obtained by clicking here or here.

Definitions to Describe Quality of Lunar Meteor Observations

In order to better qualify the probability of an observation being genuinely impact in nature, we have adopted a definitive classification scheme. The descriptors are given below

Confirmed Observation: Those impacts observed by at least two independent observers separated by at least 50 km (30 mi) within 2 degrees of latitude and longitude on the moon and 2 seconds of time (99% confidence).
Tentatively Confirmed Observation: Those impacts observed by at least two independent observers separated by less than 50 km (30 mi) within 5 degrees of longitude and 5 seconds of time (95% confidence).
Probable: Those impacts observed by a single observer having the characteristics of an impact observation--appearing on two or more video frames, a measurable point-spread-function (i.e. appearing similar to a star), and/or confidence at least 80%.
Candidate: Any impact observation submitted by a single observer with a confidence of at least 50%.

With these criteria in place, we can better group observations in terms of quality and estimate the likelihood of the observation being that of an actual impact event. It is very possible that a candidate could be elevated to the status of "confirmed" with the corroborative observation of a second independent observer, as stated in the qualifications above.

Lunar Impact Plots

Included are the plots made for meteor showers with ZHR's greater than 10 that occur when the Moon is favorably placed for the observation of impact flashes from Earth. In addition to the plots for 2005 and 2006, plots for 1999 to 2004 are also included for archival purposes. Click on the following link for impact plots showing when the Moon will be favorably placed to observe possible lunar meteor impacts on its surface from annual meteor showers. Only when at least some of the dark side of the Moon is presented to the Earth, and the terrestrial ZHR of the shower exceeds 15, is the plot for that particular shower (terrestrial) maximum provided. Many thanks to Peter Gural of Science Applications International Corporation for providing these impact plots. Also note that the LunarScan program is capable of producing lunar impact plots for any shower and any lunar phase; interested parties are encouraged to refer to the documentation that goes with the program for more information.

Lunar Impact Plots--Archives

Lunar Impact Plots--Current Observable Events

2005-2061 for 7 major annual showers