Order of Kilopi
I am all for starting our moon rotating, so that it can be
explored from earth bound telescopes.
It is totally 'spinless' currently, I can't see any negative
impact if it was to be forced into a slow spin that would slowly
reveal it's dark side for scientific discovery.
Established Member
Do we have what it takes to make that happen?? How big and fast of a guided asteroid would you need at the most efficient angle to create spin?
Order of Kilopi
Two things. One is that it is currently spinning. And secondly, do you think it would be more feasible to get the moon to spin or to build an number of orbiting telescopes to take pictures of the moon?Originally Posted by Eric Vaxxine
As above, so below
Banned
... Yes. Not so long ago some very high resolution images of the landing sites of the Apollo missions
was posted not too far from here... The orbiting space craft that sent those images has been mapping the moon
with that same high resolution..
The idea of setting a energy into the rotation as to alter its rate enough.
Is achievable but would require a massive input of energies.. or would it ?
Just maybe a grid of solar panels could initiate a motion... naa, all a little costly and not required..
Order of Kilopi
Like LRO, Kaguya, Chang'e, and Chandrayaan-1, to just count some of the recent ones. Lunar orbiters had Earth-based telescopes beat in the '60s, though LRO is in a class by itself.
I say there is an invisible elf in my backyard. How do you prove that I am wrong?
The Leif Ericson Cruiser
Order of Kilopi
So many issues.
Firstly - why?
We have spacecraft right now in orbit around the Moon than can 'explore' it in resolutions 2-3 orders of magnitude better than anything on Earth. They have mapping spectrometers, laser altimeters, magnetometers and so on. What, from an 'exploration' perspective is the benefit of this ( answer, none )
Secondly - how?
As a first order approximation - assuming the moon to be a uniform sphere - mass of 7.3*10^22kg, and radius of 1738km it has a rough moment of inertia of 8.9*10^34. Let's say we want to make it rotate...meh..once a year? I think, thus, roughly, the rotational kinetic energy involved in making that happen is about 1.76*10^21 joules.
The international space station has kinetic energy of roughly 1.3*10^14 joules. Thus - you need the energy equivalent to 10,000,000 orbiting ISS's to make the moon change it's rotational rate by one revolution per year. (Answer, it is, practically speaking...impossible)
Thirdly - what dark side?
The moon doesn't have a 'dark side' any more than a football does. We only see one side of it ( well, given libration...about 59% of it ) but when the 'far' side is dark, the near side is lit...where the 'near' side if dark...the far side is lit. You do know this, right?
Are you having us all on with this, or are you for real?
Established Member
With my limited knowledge of the Earth/Moon gravity and tidal lock.
If you were to input energy to change the rotational period would you not have the side effect of changing it's orbit?
Established Member
Plus the tidal forces will tug on the moon, trying to slow it down to -- wait for it -- one revolution per orbit!
Order of Kilopi
Why do you keep posting this? BAUT is a place to counter misconceptions, not promote them.
Order of Kilopi
yes - this is an effort you would have to continually re-do, as the moon wants to be tidally locked and will regress to that lock if un-altered.
Established Member
Global warming is because of excess energy on Earth. If we convert that thermal energy in the atmosphere into rotational energy on the moon and stop the moon's rotation, we would solve the problem and get to see some really neat craters while ridding our language of the lunar misconceptions relating to the dark/far side of the moon, at least until tidal locking brings it back into a near side/far side alignment. And when we do get back to a tidally locked situation, the day will be longer, which addresses everyone's complaint that there aren't enough hours in the day to do everything that needs to get done.
Back to the OP. I don't see any scientific reason that we would benefit from this. As mentioned earlier, we already know what the far side looks like. Also, there is occasionally fanciful talk of setting up a radio observatory on the far side, in which the moon blocks out all of the radio transmissions from Earth. While there would be long stretches in which the Earth is below the horizon, there would also be undesirably long periods where the Earth is above the horizon and interfering with the radio telescope.
Established Member
How would Earth rise above the horizon of the far side (outside of the areas that we can see due to libration)? There would be long stretches where the SUN would be above the horizon, potentially interfering with some frequencies, but Earth? No.
CJSF
"In the nightgown of the sullen moon, How the windows lean into the room, In the nightgown of the sullen moon."
-They Might Be Giants
Established Member
Currently, the moon rotates once per month, which means that the same side always faces the Earth. If we stop that rotation, that means that in the course of a month, every point on the moon (with maybe a few exceptions near the poles due to libration) will be facing the Earth half the time and away from the Earth the other half. From a lunar perspective that is the same as saying that the Earth is above the horizon half the time and below half the time. This doesn't mean that the side facing the Earth will be lit by sunlight, but over the course of a year, the entire area of the moon should be visible from Earth at some point.
Established Member
Oh, you were talking about a radio telescope AFTER the purported "spin up" of the Moon, not under the current conditions.
Got it!
CJSF
"In the nightgown of the sullen moon, How the windows lean into the room, In the nightgown of the sullen moon."
-They Might Be Giants
Established Member
On re-reading my post, I realize that I jumped back and forth between current and "proposed" lunar spin scenarios unnecessarily. Sorry about the confusion.
Established Member
We barely had the technology to send three guys and a few tons of capsule to the moon.
You're grossly underestimating the amount of power we can generate in any way to even speculate about this....
Order of Kilopi
Indeed. But as an intellectual exercise, let us suppose we had two Earth-like planets rotating around a common center--say from a super-Earth being split in the distant past--only another impactor caused the smaller of the two worlds to rotate opposite from its revolution. The larger planet rotates west-to-east as we do--but the other, east-to-west.
The North pole is where ours is on the larger of the two--the opposite on the other.
What interesting electrical effects might we see--how would their magnetospheres react to one another--could they link up on the same cycle over time, and could charged tethers be used for simple back and forth travel?
Banned
In reply to 'Justafriends' post.. Yes I agree.
With some energy input a change could be introduced.. not like flicking a light switch..
complicated and slow. I can not see any reason why such would be wanted..
As our ability to go there improves.. and that it will.
Negates the need or want to wast effort on a meaningless and expensive exercise.
Banned
Out on the spiral arms library there is a notice...
" Humanity now extinct.
It is believed after changes to the rotational velocity brought the Moon into conflict with Earth.
The destruction was complete. The third planet of Sol, is now a asteroid belt."
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