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back to article NASA's orbiting space-broadband probe LADEE beams back Moon snaps

NASA's LADEE (Lunar Atmosphere and Dust Environment Explorer) probe orbiting the Moon has sent its first images of the lunar surface and the surrounding stars as it fine-tunes its navigation system. The satellite, which was launched in September during an unintentional amphibian barbecue, spent the early part of the past month …

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Coat

Maybe just maybe

"The Moon's surface is covered by a thin layer of very fine dust, the smallest remains of meteorites and other space debris smashing down. It's highly abrasive and clings to everything due to its electrostatic charge, so could make lunar living more troublesome. Thus, NASA wants to understand what's going on."

Perhaps, since the dust floating above the surface is the same as the dust which makes up the surface. A such it have the same electrostatic charge and like charges repel. Add in a bit of brownian motion and Bob's your uncle^H^H^H^H^H lunar sunrise.

Mine's the one with a few grand worth of lunar rocks in the pocket.

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Silver badge

Re: Maybe just maybe

I'd go with a different explanation. Lunar dust ejected by meteorite impacts, orbiting the moon for years, some of it at small altitude, some of it in bigger orbits around the moon or even Earth. The Moon's 'atmosphere' causes no drag to these dust particles, so they can remain there for a long time.

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Re: Maybe just maybe

"I'd go with a different explanation. Lunar dust ejected by meteorite impacts, orbiting the moon for years, some of it at small altitude, some of it in bigger orbits around the moon or even Earth. The Moon's 'atmosphere' causes no drag to these dust particles, so they can remain there for a long time."

It would have to be ejected on just the right trajectory and at just the right (extremely high) speed to orbit at a low altitude - but higher than all the mountains - even in the moons gravity and be unaffected by solar wind for a long period of time so I think thats pretty unlikely. Electostatic effects with the dust - which is far finer than any dust on earth - is far more likely.

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Re: Maybe just maybe (@ Boltar)

It would have to be ejected on just the right trajectory and at just the right (extremely high) speed to orbit at a low altitude

The lack of a proper atmosphere in the Moon allows for far more meteoric impacts (and at greater speeds) than in the Earth. At these speeds and without atmospheric drag, the probability of a small part of the ejecta reaching near-scape velocities is, in my opinion, very high.

And if it was caused by electrostatic effects, you could expect the dust floating only a few centimetres over the surface.

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Re: Maybe just maybe (@ Boltar)

Four points off the top of my head, every one of which shows your theory not to be plausible:

1. There is drag, just less of it. But for a microscopic dust particle, it would be enough to bring it back down eventually. Even if that 'eventually' is years (very unlikely), there wouldn't be enough dust suspended like this to cause a visible haze. There would also be a hell of a lot of collisions between bits of dust, since there would be no uniform orbit direction, and the 'orbitting' dust would cause one hell of a constant storm for anyone on the surface.

2. Mountains. If this theory was true, there would be no dust below the levels of the highest peaks. This would be very easy to show.

3. Luck. Certainly impacts can throw stuff out of the lunar gravity well, but how many bits of dust would land exactly in the orbit level which aligns to the speed they have? Basically, none. So the orbits would all decay, and the dust would clear.

4. If this did happen (which it doesn't), there would also be rocks of all shapes and sizes doing the same. There aren't.

The point is that just because there isn't consensus about what exactly is happening, there are some things which are clearly not happening. A lack of an understanding of the physics is not the same as a lack of the physics.

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Silver badge

Re: Maybe just maybe (@ Boltar)

" At these speeds and without atmospheric drag, the probability of a small part of the ejecta reaching near-scape velocities is, in my opinion, very high."

Escape velocity? Sure. But just the right orbital velocity so it doesn't come back down again very soon? Very unlikely - though possible. And as someone else said - it shouldn't just be dust doing it , there should be large rocks and boulders too.

"And if it was caused by electrostatic effects, you could expect the dust floating only a few centimetres over the surface."

Who says there isn't? Dust thats only visible when seen on a horizontal view through tens of miles of the stuff towards the horizon isn't going to be visible close up on short range moonwalk pictures.

Anyway , my uneducated guess is that dust from micrometeorite impacts is kept aloft in some unknown way by a combination of static and solar wind effect possibly with help from some localised magnetic hotspots. I'll bet this effect only occurs on the daytime side.

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Re: Maybe just maybe (@ Boltar)(@AndyS)

Pfffff... All right, I'll bite:

1. There is drag, just less of it...

From TFA: ...but is one hundred trillionth to that of Earth at sea level – a science lab would consider the "atmosphere" on the Moon to be a pretty good vacuum.

There's A LOT LESS OF IT.

Even if that 'eventually' is years (very unlikely)

So you say. Given the way the probability of collision decreases with the amount and size of the particles involved, this doesn't seem so unlikely, does it?.

2. Mountains. If this theory was true, there would be no dust below the levels of the highest peaks.

Small fallacy here. Not all the particles will impact the highest mountain, will they?

3. Luck...

It isn't luck, it's statistics.

...but how many bits of dust would land exactly in the orbit level which aligns to the speed they have?

All of them, obviously :-D. Now, seriously, with the conditions in the Moon's surface, most meteoric impacts will cause a small fraction of the particles to reach orbital speeds, however short lived those orbits could or couldn't be.

So the orbits would all decay, and the dust would clear.

Unless new impacts were creating more dust, as seems to be the case.

4. If this did happen (which it doesn't), there would also be rocks of all shapes and sizes doing the same. There aren't.

There are. Per the reasons stated above, a fraction of meteorites hitting the moon are ejecta from previous collisions.

If I had to place a bet, I'd say that there is a 'ring' -albeit a tenuous one- of lunar dust and debris orbiting the Moon and another one orbiting the Earth, and that the Moon is clearing a path through them, just like Saturn's moons do.

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Re: Maybe just maybe (@ Boltar)

"it shouldn't just be dust doing it , there should be large rocks and boulders too."

If the probability of an "object" ending up in a relatively stable orbit after a meteorite strike is, say, a million to one, then we also need to consider how many rocks compared with dust particles are ejected per strike before we can make any kind of projection of stable orbit ejections there may be.

There's probably quite a few more dust particles ejected as opposed to pebbles, rocks or boulders.

(I am, of course, assuming a roundworld rather than a discworld where, as we all know, a one in a million chance is a dead cert)

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Bronze badge

Re: Maybe just maybe

The moon is not conducive to low orbits. Its surface mass concentrations send satellites slewing off-orbit very rapidly; some of the Apollo sub-satellites lasted only months before the moon's lumpy gravity field helped them perform unplanned lithobraking maneuvers.

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I wonder if the "Kamikaze dive" will be aimed at the Jade Rabbit

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Mushroom

Is There an Elmer Fudd on the NASA Pay roll and when does "wabbit hunting season start"

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And when it happens

I expect el Reg's headline to be "LADEE bits FOUND ON MOON".

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Anonymous Coward

@ Lesley Woodlouse

1. This isn't your office, where you can get hired by clients

2. This isn't a bar and you're clearly not talking the "toot", and there is no sign of Fangio or a dame that can do you wrong. Ditto on the head knocking.

3. This isn't an alleyway, and if you try shooting anyone around here you're likely to get into a lot of trouble (so you may be able to fulfill the sticky situation portion...)

4. This isn't a rooftop, there is no villain, and there can't possibly be a final showdown.

Apart from subsection(iii) of point 3 above, you are clearly in breach of contract and must hand in your trusty Smythe and Weasel at your earliest convenience. You will also need to make sure that your fedora and trenchcoat are fully dry cleaned and returned in a state of complete repair. Any other clothing (mentioned or otherwise) are your own business.

We don't expect to hear from you at anytime in the immediate future, however if you do choose to appeal the above decision, your submission should have already been sent to us 3 weeks ago at the following address:

Hugo Artemis Solon Saturnicus Reginald Arthur Rune & Associates

664 Moby Dick Terrace

Butts Estate

Brentford

TW8 0LP

Good day to you sir.

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Bronze badge

:(

Not too keen on all this crashing stuff into celestial rock objects, surely we can do our science better than that. I support flinging it off somewhere distant to be found later by a benevolent overlord.

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Re: @ Lesley Woodlouse

I am on a rooftop, using Hugo's Windows 28 tablet that Barry brought back from the 24th Century

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Anonymous Coward

Oh yeah,

Moon to Earth (238k miles) 622Mbps with a proper upgrade plan in place.

Exchange to my house (2 miles) 6Mbps (if I'm Lucky) and no upgrade plan in sight!

Come on KC, pull your fingers out...

If their worried about all that dust, someone at Nasa must have a hoover (vacuum) for the job.

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Happy

Would it be a dyson by any chance

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1.25Gbps of encoded traffic

"An upgrade, to be tested in 2017, should allow 1.25Gbps of encoded traffic, or 2.88Gbps of unencoded."

But Virgin media throttle it by 50% between 17:00 and 22:00hrs.

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Pint

622 Mbps and they didn't bother including a tiny hi-res camera?

Seems like a missed opportunity.

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Black Helicopters

FRESH IMPACT CRATER

I'm too late to post a comment on the original story, so I'll put this here:

How come the NASA images of the Martian impact crater are date-stamped 15/09/2009 15:51???

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