Can someone please explain why I don't see a blast crater in the dust beneath the Apollo lunar modules?

Question

I'd really like to hear a good, science-based explanation for this. I can't figure it out. I have been able to explain away several of the conspiracy crowd's arguments, but the absence of blast craters beneath the LM's is a tough one. I've examined tons of photos, but they are all pretty much the same. There isn't even any dust on the LM footpads that should have settled back down after landing. This is really bizarre.

If you have the answer, or even just a theory, please let me know.

Thanks folks!

I hope this doesn't overwrite my earlier details, but I should clarify a few things. The Eagle weighed 16 tons (5,500 lbs on the moon). It landed on a dusty surface (Remember Neil's historic footprint? Dust.) The Eagle landed straight down, no sliding, skidding, or bouncing. It fired its rockets downward against the pull of gravity to land gently.

So, how do you land a vehicle weighing nearly 3 tons on a dusty surface, firing downward facing rockets to ease your descent, and stir up absolutely no dust? After the Eagle was down and the rocket engines were shut off, no dust had been disturbed. None settled on the LM's footpads. (In fact, photos show that the dust around the footpads show very little disruption, so impact was gentle. That means hard-firing engines.) But it was certainly present for a footprint.

This is what I cannot explain. Most of the other conspiracy ideas I have answered, but this one is a tough nut to crack. If you have the answer, please let me know.

Answer 1

Look at a picture of the Lunar Excursion Module (LEM). When blasting off from the moon, only the "ball" part of it leaves the surface. The landing gear and the rest of the LEM below the "ball" act as a launching pad. The blast effect of the LEM's engine is dissipated because its blast effect is reflected up into space by this launchpad.

As for the blast from the initial landing...the LEM is moving at a fairly slow rate when the retro is fired for final landing. This blast blows the approximately 1 foot of moondust away from the landing site. This blast is only concentrated in a particluar spot for a very short amount of time, something like 15 seconds. The temperature of the blast is only hot enough to melt the moon's crust into more moondust for the last 50 meters of descent, which only takes the LEM 10-15 seconds to fall. If you were able to physically measure the blast crater caused by this landing, you would see that it is very slight...almost nonexistent, due to the very short time (10-15 sec.) of sufficient blast force to make said crater.

Answer 2

a) why would it settle back when the moon's small gravitational attraction means some of the dust may have been blown to the other side (nearly impossible, but seems more dramatic this way)
b) the surface of the moon is quite hard. It's not made of silica, you know (!). The landing module does not produce enough combustion reaction to blow a huge hole in the surface, otherwise how would the module land? When the return module is launched, its actual rocket is small and can never make a crater, especially since it blasts off from above the landing module.

Answer 3

I'll try. For one thing, since there isn't an atmosphere like we have on earth, there is very little resistance against the motion of the particles that are being blown from the engine exhaust. Although there is a crater it is oblique and almost imperceptible. Without atmospheric pressure, humidity, and the gravitational pull of the Earth, dust that is jettisoned on the Moon will travel farther and disperse over a wider range. That is why you can't see dust on the LEM's feet. But some is there, it's just very difficult to see. Upon lift-off from the Moon, the base of the Lunar Module is left behind and ablates the effects of the engines.

Answer 4

Phil Plait at badastronomy.com has an excellent article about the Fox TV hoax special. Here's some of what he has to say about the missing blast crater:
" the engine nozzle was about 54 inches across (from the Encyclopaedia Astronautica), which means it had an area of 2300 square inches. That in turn means that the thrust generated a pressure of only about 1.5 pounds per square inch! That's not a lot of pressure. Moreover, in a vacuum, the exhaust from a rocket spreads out very rapidly."

Answer 5

I am at a loss as to why you would expect to see a 'blast crater' beneath the lunar module?

They touched down softly so as not to crush the astronauts inside, and when they returned to lunar orbit, the landing gear frame of the LM would have dissipated the force from the small blast they used to get back off the lunar surface.

Answer 6

didnt you hear tjhat it was a multimillion dolor fake event to out wit the russans in the cold war

Answer 7

well, we all know it was fake so that the U.S population wouldnt panic as to think that the russians could attack us from space

Answer 8

everything they've ever told you is a lie.