The Discovery of the Apollo 12 Lunar Module Impact Site
GoneToPlaid's 11/21/2013 Discovery
The Apollo 12 LM Intrepid's impact site was discovered by GoneToPlaid (me, since I never use my real name online) on the evening of 11/20/2013. I reported my discovery via email on 11/21/2013 to Alan Bean (Apollo 12 LMP), Eric Jones and Ken Glover (editors of the Apollo Lunar Surface Journal), Andrew Chaikin (author and contributor to the ALSJ), and professor Ulrich Lotzmann (ALSJ contributor, discoverer of numerous asteroids, and discoverer of two periodic comets).
My discovery initially remained confidential since I needed to perform further research in order to confirm several of my hypotheses about the remarkably unusual circumstances regarding how this impact site could have possibly been created by the lunar module which the Apollo 12 crew most appropriately named Intrepid. This research involved terrain modeling versus LM trajectory and impact angle from the horizontal, confirmation from Apollo astronauts that the LMs were fully pressurized after being jettisoned from the CMs following ascent and orbital rendezvous, and performing basic physics calculations for what is essentially a pressurized aluminum can traveling at a velocity of over 3700 miles per hour which would rip open and explode within 1 to 5 milliseconds after making contact with the lunar surface. Since I am not a scientist, I had to perform further research during my limited free time. Thus it took me until 04/12/2015 to complete all of my research and to confirm that this really is the Apollo 12 LM Intrepid's lunar impact site. I published this web page about my discovery on 04/15/2015.
My confirmed discovery was once again reported via email on 04/11/2015 to the same parties as above. I then reported my confirmed discovery via email directly to Dr. Mark Robinson (principal investigator for the Lunar Reconnaissance Orbiter mission) on 04/12/2015. Dr. Robinson forwarded my email to on 04/13/2015 to planetary scientist Jeffrey Plescia at John Hopkins University. Jeffrey Plescia formerly worked at the USGS and at JPL. I received an email response from Jeffrey Plescia on 04/15/2015, asking for the impact site coordinates. I replied via email to both Dr. Robinson and Jeffrey Plescia on 04/15/2015. I emailed Dr. Mark Robinson and Jeffrey Plescia with a link to this web page which listed the LM impact site coordinates and which provided direct links for viewing the impact site using the LRO Team's QuickMap web site, and with contact information for the people at NASA who I had also contacted about my discovery . In my email, I asked Jeffrey and the LRO Team to confirm my discovery so that NASA and the LRO Team could issue a press release about the discovery. I never heard back from either of them via email or by phone. I subsequently emailed additional information to Jeffrey Plescia on 04/17/2015, yet I did not receive any reply. Jeffrey Plescia and the LRO Team never followed up my request to confirm my discovery.
As mentioned, on 04/15/2015, I reported my discovery via email to my contacts at NASA, and to the same parties for the 11/20/2013 email. Specifically, I additionally reported my discovery to these people at NASA: "Barry, Bill (HQ-NH000)" firstname.lastname@example.org, "Ulrich, Bert (HQ-NG000)" email@example.com, "Brown, Fred A. (HQ-NG000)" firstname.lastname@example.org, "Feinberg, Al (HQ-NG000)" email@example.com. This same email was also sent to ALSJ contributor David Woods and to former NASA Administrator Michael Griffin. I received enthusiastic responses from David Woods and Michael Griffin. I never received any email responses or phone calls from NASA.
On 07/21/2015, I emailed Stuart Robbins, a research scientist at Southwest Research Institute (SwRI), about the discovery of the Apollo 12 LM impact site. I never received a reply.
Associate Professor Phil Stooke's 05/21/2016 Discovery
Since my emails and this web page's details about my discovery of the Apollo 12 LM impact site were ignored by both NASA and the LRO Team, Phil Stooke correctly is an independent co-discover of the Apollo 12 LM impact site.
Phil Stooke, a professor at the University of Western Ontario (Western University), independently discovered the Apollo 12 LM's impact site. It appears that Phil independently discovered this impact site on or about 05/20/2016. See Phil's post about his independent discovery::
Phil must have discovered the impact site somewhat earlier than the date of his above post since Phil's attachments show that Phil had already performed considerable post-discovery work to document his independent discovery. I will update Phil's independent discovery date once Phil gets back to me with information about his true independent discovery date.
Phil realized, just as I did, that there must be an initial point (IP) of contact between the lunar module and the moon's surface. Whether or not this IP would be readily visible was an entirely different question. Yet we both reasonably assumed that some sort of IP contact scar should be visible while backtracking along the centerline and bearing of the debris field and that it should be a simple matter of locating it. Actually, this was not quite so simple since one has to further backtrack along the bearing and centerline of the debris field in order to locate and rule out any other potential IP candidates. Why? Because the local terrain along this centerline is strongly undulating terrain. In any event, both Phil and I independently located the Apollo 12 Intrepid's IP impact scar. And as shown further below and after examining the DEM along the centerline which includes the debris field, the theoretical starting point of the debris field matches very well with the location of the IP which Phil and I independently identified. The IP is readily visible, yet we both had to look carefully for it and confirm that the IP impact scar was real. It took me some time to find it, and it took Phil some time to find it. On 09/12/2016, Phil posted an update about his independent discovery of the Apollo 12 LM IP:
Once again, Phil must have discovered the IP on a somewhat earlier date than his above post since his attachments show post-discovery work.
Discovery of the Apollo 14 LM Impact Site
Phil Stooke discovered the Apollo 14 LM impact site on or about 03/19/2010, a bit over four years before I independently discovered it on 04/18/2015. This is a most remarkable achievement by Phil. See:
There is absolutely no question in my mind that the true Apollo 14 LM impact site has been correctly identified since there is absolutely nothing even remotely nearby the vicinity of the impact site which could be an alternative candidate for the Apollo 14 LM's impact site.
Other Apollo LM Impact Site Candidates
Phil has a possible A15 LM impact site candidate which I need to research and verify. I had previously (and perhaps too quickly) ruled out this possible A15 LM impact site candidate, yet Phil has presented additional evidence which I need to investigate. If this really is the A15 LM impact site and since I initially rejected this potential A15 LM impact site location, then this discovery would be entirely Phil's discovery, with me only serving to confirm his discovery by presenting evidence to confirm his discovery.
I have a strong candidate for the A17 LM impact site. I believe that Phil also has a different candidate for the A17 LM impact site. At this point, it is down to a matter of either proving or disproving each candidate. I hope that Phil and I can work together to confirm any A15 and A17 LM impact site candidates.
The Apollo 12 Lunar Module Impact Site
The Apollo 12 LM Intrepid approached from the east on a bearing of approximately 285° clockwise from lunar north. Thus the Intrepid was traveling in a west-northwesterly direction. This bearing is almost exactly the same bearing on which the Intrepid traveled on during its descent and landing to mark the second time in mankind's history in which human beings landed and set foot on another world. The Intrepid's angle of descent at impact was 3.7° from horizontal and its velocity at impact was 1680 meters per second (3758 miles per hour). That is far faster than the top speed of a Lockheed SR-71 Blackbird yet somewhat less than the top speed of the North American X-15 research aircraft.
Apollo 12 LM Impact Site Data
LRO Team QuickMap View of the Impact Site
A12 LM Impact Site 0.5 m/pixel (full link) - QuickMap - QuickMap view (link with full URL) showing a 0.5m/pixel close-up view of a fairly small part of the debris field. This view is centered in between the two bright and fresh secondary craters which may have been created by large pieces of the LM Intrepid. A short bit.ly URL which is suitable for use in news articles is: http://bit.ly/1FHnBat
NOTE: To see the entire debris field while viewing either of the above QuickMap links, simply click the minus (-) zoom button twice to zoom out from 0.5 m per pixel to 2 m per pixel. This setting will show the entire impact site and debris field if your computer has a horizontal resolution of 1920 pixels or greater. Laptop users with lower resolution screens will have to click the minus zoom button one additional time in order to see the full extent of the impact site.
Google Moon KMZ File for the Impact Site
A12_LM_Impact_Site.kmz 63 MB KMZ file of the impact site for use in Google Moon. Since this KMZ file is rather large, you may wish to right-click on the link to download and save the file. After the KMZ file has been downloaded to a location on you computer, you can then open the downloaded file in Google Moon.
Videos of Apollo 12 Lunar Module Intrepid's Lunar Impact Site
The best way to see the extent of the impact site is to watch either of the following MP4 videos. Both are identical except that the HQ version has higher fidelity. In the following video, what you are looking for are the dark streaks from impact debris which appear to converge towards the distant horizon. You will note that the dark streaks do not actually converge on a vanishing point located at the center of the distant horizon. Why? Because the dark streaks are the result of an outwardly spreading fan of debris material, rather than all of the dark streaks being aligned along parallel lines. Videos are credit NASA/GSFC/ASU/Google/GoneToPlaid.
Plotting Error in the Apollo 12 Mission Report Image for the A12 Landing and Impact Sites
I have discovered that the Figure 5-2 image NASA-S-70-570 on page 93 (Section 5, page 11) within the Apollo 12 Mission Report contains an erroneously overlaid plot of the Apollo 12 landing site location and the Apollo 12 LM impact site location. See below. I aligned a crop of Lunar Orbiter IV image 4125_h3 to the overlaid NASA-S-70-570 image from the Apollo 12 Mission Report . I then plotted the actual LM landing and impact site locations in yellow. The originally plotted LM landing and impact site locations and their trajectories were highlighted in blue. The original plot was then translated to align with the actual landing site location. With the original plotting error in NASA-S-70-570 now corrected, you can see that the NASA's computed position for the Intrepid's impact site very closely matches the actual impact site location. See images below.
Where exactly did the LM Intrepid make its initial contact with the lunar surface?
This is a question which has perplexed me since I previously was unable to find any blatantly an obvious point of initial contact further back along my carefully plotted centerline throughout the length of the entire debris field. I would expect to find an obvious and very fresh crater at the Intrepid's initial point of contact with the lunar surface. The debris field itself gives us some clues since the debris field is very long and has a rather narrow fan pattern. Had the Intrepid impacted the lunar surface at a steeper angle relative to the lunar surface, then an obvious crater would have been created with ejecta being strewn throughout a much wider fan of secondary debris. Yet this is not what is seen when looking at the debris field. This lead me to suspect that part of the Intrepid must have just barely grazed the lunar surface at a very shallow angle. Assuming that this is what did indeed occur, the part of the Intrepid which grazed the lunar surface would instantly disintegrate and send shrapnel like a shotgun blast upward and into the LM's pressurized hull. The result would be a virtually instantaneous explosive decompression of the LM's hull.
So for the moment let's assume that the above scenario is what actually occurred. The LM was pressurized with pure oxygen. At 20° Celsius, oxygen molecules have an average speed of 478 meters per second. The LM's speed at impact was 1680 meters per second. Assuming that the oxygen was able to act with 100% efficiency in terms of accelerating the LM's hull fragments, then a 32° wide fan of debris would have been created. But of course this is impossible since this requires the hull fragments to have zero inertia and for the oxygen molecules to have 100% efficiency at imparting their average speed to the hull fragments. Just winging it, I figured that the oxygen would act upon the exploding hull fragments with only 50% efficiency. This results in a 16° wide debris fan. The measured angular width of the actual debris fan is a bit less than this and seems to converge at a point near the west side of an apparent ridge which is located to the east of the debris field.
The above scenario is only a hypothesis for the observed angular width and convergence of the debris fan, and for the lack of any obvious initial impact crater. The above scenario requires the LM to initially barely graze the lunar surface. This in turn also requires the local slope of the lunar surface, within a distance of only a tens of meters downrange of the initial impact point, to become greater than the descent slope of the LM at the point where the LM grazed the lunar surface such that there is a void beneath the LM and its fan of exploding hull fragments as the LM's debris fan traveled and impacted further downrange. In other words, this scenario requires the LM to graze the lunar surface at or very near the westward side of a lunar ridge.
My crash scenario would appear to be extremely unlikely. However unlikely, let's see if there is evidence for the above scenario. For an answer, we will have to look at the Lunar Reconnaissance Orbiter's GLD100 DTM data. After examining the following, you will see that the GLD100 DTM evidence not only supports this scenario, but also appears to impose an upper limit on the trajectory angle of an object which could have created the observed debris field. This upper limit is exactly the same 3.7° angle from horizontal at which the LM Intrepid struck the lunar surface. The eastward convergence of the debris field fan proves that whatever created the debris field impacted from the east and not the west. So in other words, the LRO GLD100 DTM for the debris field appears to be the smoking gun which proves that this is indeed the Apollo 12 Intrepid's lunar impact site. See the images below.
The above GLD100 data appears to support my crash scenario. But my crash scenario falls apart if I can't find signs of the Intrepid's initial point of contact with the lunar surface in the area predicted by the GLD100 data plot, and additionally find signs that the LM's pressurized hull exploded immediately above the surface a few milliseconds later and only a few meters downrange of this initial point of contact. Is anything like this visible in LRO images? The answer is YES, as shown below.
LRO Team QuickMap View of the Intrepid's Initial Point of Contact with the Lunar Surface
A12 LM Initial Contact Point at 0.5 m/pixel (full link) - QuickMap - QuickMap view (link with full URL) showing a 0.5m/pixel close-up view of the Apollo 12 lunar module Intrepid's initial point (IP) of contact with the lunar surface. This QuickMap view is precisely centered on the IP. A short bit.ly URL which is suitable for use in news articles is: http://bit.ly/1FSI5gt
Alternatively, following is a labeled QuickMap screen capture of the Intrepid's initial point of contact with the lunar surface.
The GLD100 data for the location shown in the above image indicates that the slope of the terrain at this initial contact point location and along the same bearing as the debris field is approximately -2.6°. The LM's descent angle at impact was -3.7°, for a difference of only 1.1°. Roughly 1 degree is an extraordinarily shallow impact angle. I theorize that this extremely shallow impact angle allowed the pressurized LM to explode rather than burrowing into the terrain and creating an impact crater.
So there you have it. The evidence which I presented above would appear to validate my scenario for exactly how and where the Intrepid impacted the lunar surface.
Links to LRO NAC and WAC Images of the Impact Site