Originally posted by jakyll
Yet i'm always drawn to the moon buggy.Leaving aside the questions of,how did they get that large buggy into the small rocket? and how heavy must it
have been to keep it on the ground.
I know you wanted to leave these questions aside, but to answer it quickly. The rover folded up and was stored inside the decent module. It's very
compact. Also it weighs a bit over 450lbs (on Earth) and it can hold an additional 1000lbs. And just because the Moon's gravity is less, doesn't
mean things are going to go flying off the ground at the slightest bump.
I'm interested in the moon's surface,the loose dust.
No doubt many of you have seen the footage of the different moon landings,have you noticed how the dust acts? As the buggy kicks the loose surface up
into the air,something strange happens.It falls back to the surface exactly as it would as if it was in earth's gravity!!
Well of course it falls back to the surface. The Moon still has gravity, just 1/6th that of Earths. But it doesn't fall exactly like it would on
Earth. Earth has an atmosphere. Have you see what happens when a car drives down a dusty dirt road? The dust is tossed up into the air and it clouds
and billows up and stays suspended in the air and slowly drifts back down or drifts with the breeze if there is any. You'll note that this doesn't
happen on any of the Lunar Rover video footage. All the particles of dust are tossed up by the wheels and they all follow there own little parabolic
like trajectories back to the ground. So dust will fall to the ground faster on the Moon then on Earth due to the lack of any air resistance affecting
the particles.
As the moon's surface gravity is 1.6 m/s,compared to earths 9.7 m/s,it is not possible for the dust to fall back to the ground in such a way
as shown on the video footage.If it did,it would be breaking the laws of gravity,and we'd have a new phenomenon on our hands!
How do you know it's not possible? Have you done the math to make sure?
Here's an
extremely rough calculation.
The rover's top speed was about 8mph. But I don't think it always went at full speed, but lets assume that it's going at a constant 8mph. Now I
believe that means that the outside edge of the wheel is doing that speed, that translates to 3.58m/s. I'm also going to assume that the dust is
kicked out at a 45deg angle. I'm going to ignore things like friction and particle masses and what not. The formula: Height = .25*v*v/g
so with all the numbers plugged in, .25 * 3.58 * (3.58 / 1.62) = 1.97m in height.
Additionally, if one were to drop an object from 2m in height, it would take 1.57 seconds to reach the surface.
sqrt( 2m / (.5 * 1.62)) = 1.57 seconds
This all seems relatively consistent with the rover footage that I've linked to below.
But like I said, they weren't always at there top speed. Young, from Apollo 16, said he reached 10km/h (about 6mph) at
most during
this clip of the Lunar Rover grand prix footage. And from the 1min mark, there is a moment were it looks like one of the rear wheels looses
its traction for a second and spins at a faster rate and kicks up the dust to what looks like about 2m at a 45deg angle, roughly.
Also,
here is the Apollo Lunar surface journals transcript of
the event with commentary for further details.
Is this the final proof then?
Not even close. It is how ever great evidence that shows they were actually on the Moon.