Predictions & Observations of Lunar Meteor impacts

(Return to main 'meteorobs' page.)

The Lunar Section of ALPO (Association of Lunar and Planetary Observers) has created a Lunar Meteoritic Impact Search team. The new group is headed by American amateur Brian Cudnik, one of the first to detect lunar meteoroid impacts:

One interesting development in amateur observation of meteor showers in recent years, has been the exciting opportunity to actually observe the impact on Earth's moon, of meteoroid dust particles (which are the physical cause of meteors in Earth's atmosphere). To prove that it is in fact feasible for amateurs to accurately record these events, David W. Dunham of the International Occultation Timing Association (IOTA), called for observations during the 1999 Leonid storm, with the following results:

Here is a somewhat less up to date Press Release about 6 of these 7 events, nonetheless including some supplemental information:

Those who are curious what such events might look like in a video record, can view David's page containing digitized animations of the actual impacts recorded during the 1999 Leonids, as well as many other links, including historical information:

Exciting amateurs around the world still further, were some reports that these rare lunar impacts may even have been recorded during other (much less dense) annual meteor showers such as the Perseids:

Is it possible that such a lunar impact event may have been recorded during the Leonid meteor shower during November of 2001?

The short answer to this question is, "Yes! It was possible..."

Those amateurs with appropriate equipment, who might be interested in attempting to record one of these highly elusive events, should first consider WHERE on the lunar disk to attempt their recording. A useful site for predictions about 2001's storm was semi-pro Peter Gural's excellent "Lunar Impact Plots for 2001 Meteor Streams":

(We hope this site may be updated soon with 2002 showers and beyond!)

Here is an image from Peter, describing the best areas on the lunar surface for observers to focus their instruments during that amazing storm peak in 2001. Pete's description: "The + mark on the impact plots represents the position on the Moon's surface where the radiant is at the zenith. The 'best' place to look is on the dark side or unilluminated portion of the Moon where ever there are dots on the plot. The probability of seeing an impact is higher in those regions with a denser set of dots (such as near the terminator in this encounter). Note that having the lit crescent in the field of view can cause glare and reduce one's chances of seeing an impact, so lunar impact observers should aim their telescopes towards the dark face with any illuminated lunar surface just outside the field of view."

Peter also notes: "[All] observer's should be sure to accurately record the time (to the nearest second if possible) and location of any impact flashes seen."

"Leonids (LEO), 17 Nov 2001 11:01 UT. Moon sets 1.8 hrs after sunset. ZHR = 100, 48% impacts on unlit near side w/polar graze = 11 deg."

Next of course, the potential observer should consider exactly WHEN it may be best to attempt an observation, verifying that the moon is in fact above the horizon during target observing periods...

Dr. Rob McNaught, one half of the famous "Asher/McNaught" scientific team who did such a great job at predicting Leonid meteor outbursts in previous years, has created a page to the site, where he placed extensive predictions and other information about lunar meteoroid impacts during the 2001 Leonids:

Space Scientist Bill Cooke posted the following set of summary predictions, mere days prior to the actual Leonid meteor storms:
"Using the same program I use to generate spacecraft Leonid forecasts,
I have constructed ZHR profiles for the Moon (as the Moon doesn't have
an atmosphere, the use of ZHR is relevant only insofar as it is a
indicator of the relative flux) for the Asher/McNaught and Brown/Cooke
models. Here are the details:


 Maximum ZHR:       5247.3
 Time of maximum: Nov 18 at 16.3200 UT
 Maximum flux (down to 1e-5 g):   0.26E+01 km^-2 hr^-1
 Fluence (down to 1e-5 g):   0.25E+01 km^-2

 Maximums for the various streams are:

  1799 Max. ZHR:        442.0 on Nov 18.6000 Distance:  0.00059 AUs
  1833 Max. ZHR:       5247.3 on Nov 18.6800 Distance:  0.00026 AUs


 Maximum ZHR:       1963.7
 Time of maximum: Nov 18 at 20.6400 UT
 Maximum flux (down to 1e-5 g):   0.98E+00 km^-2 hr^-1
 Fluence (down to 1e-5 g):   0.67E+01 km^-2

 Maximums for the various streams are:

  1633 Max. ZHR:        129.2 on Nov 18.8200 Distance:  0.00205 AUs
  1666 Max. ZHR:        162.8 on Nov 18.8200 Distance: -0.00115 AUs
  1699 Max. ZHR:        209.5 on Nov 18.8200 Distance: -0.00090 AUs
  1733 Max. ZHR:          2.9 on Nov 18.4400 Distance:  0.00693 AUs
  1766 Max. ZHR:        142.1 on Nov 18.5000 Distance:  0.00305 AUs
  1799 Max. ZHR:        219.2 on Nov 18.6000 Distance: -0.00196 AUs
  1833 Max. ZHR:        742.2 on Nov 18.6800 Distance: -0.00058 AUs
  1866 Max. ZHR:       1449.5 on Nov 18.8600 Distance: -0.00020 AUs

"Please note the the Asher/McNaught model gives just maxima, and that
the ZHR profile depicted in the graph is the output of my program
based, in part, on historical information. Their results are also
given for the Earth only, so what you see is my extrapolation of their
work to the Moon.

Bill Cooke
Marshall Space Flight Center"