Tintin Forums

I recall many years ago finding in a bookshop an omnibus edition of the moon adventures which included articles of when the original adventure was published in Tintin magazine. It included scenes which were published in the magazine but did not make it to the book.

The scene that I am referring to is when the Thompsons are making their way back to the rocket after finding footprints and claiming that there are other people on the moon. They suddenly become lost. Tintin and Haddock get into their own suits and set off to look for them. They arrive just in time to stop one of the Thompsons removing the helmet of the other on the grounds that he needs some air because of his sweating and heavy breathing - which of course is due to his sudden lack of oxygen.

I recall that at one stage a delirious Thompson threatens Tintin with his gun. I think Tintin explains the purpose of this "gun" before snatching it back, but I have forgotten what it was.

Tintin and Haddock are shown with gun holsters when exploring the cave, but Herge would have known that firearms would have been next to useless in an airless environment. So what would they have been for? Has anyone else seen this scene with the Thompsons? Does it explain what such "guns" were for?

Why? I'm fairly sure the gun-powder in bullets would still combust, as it contains all the chemicals necessary to do so (I believe you could even fire a gun under water, provided that you did it quickly enough so the powder didn't get wet), and doesn't need additional outside air to work. Chemical rockets work fine in space using similar science.

If anything the bullets would travel better and further on the Moon: a vacuum means they wouldn't be impeded by an atmosphere, and under the lower gravity on the moon they wouldn't fall as fast.
My vote is that Hergé was quite correct (technically - can't say morally) to supply conventional firearms.
You'd have to allow for the reaction forces, of course, and brace yourself, otherwise you'd go off like a rocket in the opposite direction...

And if the bit came to the bit, you could always throw the gun... ;-)

What were the guns for, anyway, though? There are obviously no "space-monsters" on the moon, not in Tintin anyway, and they weren't expecting to end up with goons aboard their rocket!

Well, that's with the benefit of hind-sight: they couldn't have known that before they went, not for certain, so better safe than sorry. The guns were for protection against the great unknown.
There could have been any manner of beastly horrors lurking in the depths of the lunar caverns, just as there was a yeti hiding up the Himalayas.

Actually, even better, I think that if you fired the bullet at exactly the right speed on an atmosphere-free sphere like the moon, gravity wouldn't bring it down to the ground at all, and it would keep going round the moon in extremely low orbit indefinitely. I think I'm right in saying that the reason satellites can stay in orbit round the earth without coming back down is only the lack of any air friction in space. (It's not because you sudddenly get free of the earth's gravity when you enter space, which you obviously don't).

I think you have to make the satellites go forward at exactly the right speed, so that the gravitational pull back to earth is exactly balanced by their forward force (which if too fast to be countered by the gravity, would send them off in a straight line into space).

I believe that if you built a continuous vacuum tube all the way round the earth, even at ground level, and fired a bullet (or anything) along it at just the right speed, it would orbit the earth inside the tube forever.

However, I may be wrong, of course. If someone whose knowledge of physics is better than mine (which wouldn't be difficult!) wants to contradict and correct me (or explain it more clearly!), feel free.

I don't think any of this really answers the question of why they'd take guns to the moon, unless they were planning to conduct orbiting bullet experiments along the lines outlined above. I suppose having one of the Thom[p]sons fire a bullet into the distance, only to have it come round from behind many hours later to hit him or his colleague might have been quite entertaining.

But Jock's probably right that a gun or two simply seemed like an expedition-y thing to take to an unknown place. Unless the guns were for protection in the event of accidentally landing the rocket back down (or being forced down)in a hostile part of earth. Their rocket-building programme had been hindered by armed spies, of course (one of whom had shot Tintin in the head), and the baddies had also tried to steal the unmanned prototype rocket by taking it off course. So maybe Baxter wanted to take no chances.

Ah, good point! However, it would have to be going somewhat faster than the typical speed at which a bullet leaves the barrel of a gun (1km per second, approx.) to do so.

If it reached 2.39km per second, it would actually attain escape velocity if you fired it straight up from the lunar surface, so I imagine the orbital velocity must lie somewhere between those two figures.

The rest of what you say sounds good to me, although I too can't make great claims for my physics!

Some more amateur ballistics. Although it never sounds like it should be so to me, if you were to fire a gun held horizontal to a flat surface, and simultaneously drop an identical bullet, they both would hit the surface at the same moment; lunar gravity being a sixth of the Earth's, the bullet would travel at least six times as far in that interval as it would down here, with a further margin added on due to the lack of atmospheric resistance.

I'd not heard that one, and agree that it sounds very counter-intuitive - but that probably means it's correct, though!

But the point is that Tintin and Haddock are armed when they explore the cave, long before they are due to return to Earth or are even aware of Jorgen's presence and I do not go for the moon-based Yeti either. Calculus makes it clear that he does not believe on the existence of other beings on the moon.

I'm sorry, I didn't mean to suggest that there was a yeti on the Moon; I just used it as an example of a creature which might have posed a threat. If you think about it, there wasn't any reason to take rifles up the Himalayas, but they did, and nobody questioned that.
In regard Calculus not believing that there was life on the Moon, that is all well and good, but what if he'd been wrong?
I'd have thought that he probably didn't believe in the yeti either, come to think of it, and he'd have been wrong there...

Would guns really work, though? Jock has said that he thinks that the cartridges contain all the necessary materials to combust. However, combustion is the same thing as oxidation, which can only happen in an oxygen-based atmosphere. Unless there is a sufficient amount of oxygen somehow sealed into the propellant, the gun would not be able to fire.


Well, if they ran out of food, the rifles could come in handy (provided they could find any wild animals).