Explosion on Moon Spreads Moondust

Jotii writes "NASA scientists have observed an explosion on the moon. The blast, equal in energy to about 70 kg of TNT, occurred near the edge of Marethe Sea of Rains on Nov. 7, 2005, when a 12-centimeter-wide meteoroid slammed into the ground. The main danger of such explosions is the static and toxic moondust, which is thrown around."

Comments

Danger?

[Tx]

The main danger of such explosions is the static and toxic moondust, which is thrown around.

Danger to whom exactly? Should I be hitting the bunker to dodge that toxic moondust?

Re:Danger?

[Anonymous Coward]

Danger to whom exactly?

To the man on the moon, silly!

-Sj53

Re:Danger?

[Jotii]

Danger to whom exactly?

To the astronauts. The dust is poisonous, is flung rapidly, and sticks to the astronauts.

Re:Danger?

[aussie_a]

Because the moon is crawling with astronauts. I think there's about one person on the moon, and he's dead. And he's been burnt so it's really only his ashes on the moon.

Re:Danger?

[Jotii]

The dust is not a problem, it might become a problem, e.g. if more astronauts walk on the moon or if outposts are built, both of which are highly likely to happen.

Re:Danger?

[HermanAB]

Well, any moonestrials should be immune to moon dust... or maybe not, which would explain why there aren't any.

So, if you find yourself outside on the moon, without the luxury of a space suit, don't breathe in...

Re:Danger?

[DeathByDuke]

moon dust is heavily corrosive, its not fine grained smooth surfaced like the dust on earth, it hasnt been 'weathered' etc and so still has spikes etc on its surface. Apollo astronauts found it corroded a lot of their equipment and spacesuits due to the friction and the tearing properties of the dust.

Nasa has reason to be concerned since it could tear open a spacesuit or corrode a bases walls over time.

Re:Danger?

[wooferhound]

I would also add . . .
Don't breath out eather !

Re:Danger?

[pnewhook]

moon dust is heavily corrosive, its not fine grained smooth surfaced like the dust on earth

Actually it can be very fine grained. The closest analogy I've seen officially used for testing vehicles for the moon is fine dry Portland cement.

Dust on earth is primarily ash, flakes of skin, dust mites, and dust mite fecal matter, so moon dust is certainly not like earth dust.

Re:Danger?

[uncl_bob]

What are you talking about, and how is this related to the parent post??

Re:Danger?

[BlindRobin]

moonestrials
shouldn't that be lunestrials?
or would that have some side effects including drowsyness ?

Re:Danger?

[mattwarden]

The danger is that the moondust might corrode the aiming system on our friggin moon-based laser beam.

Re:Danger?

[VJ42]

The Clangers perhaps? I expect that the soup dragon isn't too happy either.

Re:Danger?

[HermanAB]

I would guess that the side effects of breathing moon dust in vacuum, would be rather more extreme than drowsiness. Someone should launch an epidemiological study, a double blind test: 50 volunteers to breathe moon dust and the other 50 to breathe pure vacuum as a placebo...

Re:Danger?

[v1]

What I was wondering is, when exactly is moondust considered toxic? When inhaled I would venture a guess.

And just who do they think is breathing on the moon?

Re:Danger?

[ScrewMaster]

I think you mean "Lunarians".

Re:Danger?

[MrKibkibs]

I think it's quite obvious, there was a sailor on the bottom bunk.

Re:Danger?

[jcr]

Abrasive, not corrosive.

-jcr

Re:Danger?

[Fishstick]

a dead person on the moon? when did this happen?

Re:Danger?

[Anonymous Coward]

You seem to be thinking about indoor dust. What about dirt, rock, sand and ice.

Re:Danger?

[jnik]

Gene Shoemaker

Re:Danger?

[brucifer]

I think the term you are looking for is "Mooninites". Observe this transcript of part of a recent visit by some of their more advanced citizens.

ignignokt: we are the mooninites and our culture is advanced beyond all that you can possibly comprehend with 100% of your brain
frylock: oh is that so and what is so advanced about it
ignignokt: well for 1 thing the moon has 1/3 less gravity than your earth i don't know if you can understand that but our vertical leap is beyond all measurement
frylock: so what your saying is your culture is more advanced because you can jump higher?
ignignokt: yes observe
(jumps)
ignignokt: its not working here err come in here help me explain our advanced ways hurry
err: did you mention the spelling?
ignignokt: yes we're excellent spellers challenge me
err: yes challenge us both

Re:Danger?

[pnewhook]

Depends where you live but where I am I'd guess the major content for outdoor dust is pollen and various forms of pollution.

Re:Danger?

[Upsilon Andromedea]

Danger to whom exactly?

Future astronauts. Past astronauts did not have to deal with a corrosive dust cloud floating around.

Re:Danger?

[j79zlr]

So all of those other craters just formed themselves?

Re:Danger?

[sd_diamond]

Dust on earth is primarily ash, flakes of skin, dust mites, and dust mite fecal matter,

Well, that's the last time I empty my vacuum cleaner's basket without gloves.

Re:Danger?

[Upsilon Andromedea]

The bogyman that you see, although not as scary as the bogyman that you imagine, is always more frightening, albeit less of a risk, than the bogyman you don't see. :)

Re:Danger?

[kfg]

Future astronauts.

They better get there in a hurry. The dust is falling at 1.6 m/s^2.
Ya see, there's no air to keep it wafting about.

Past astronauts did not have to deal with a corrosive dust cloud floating around.

They did a lot of shit we call by the technical term, "walking." Bit driving too. Not to mention the fact that the moon gets wacked by space rocks at a pretty good rate. Ever see a meteor shower? Remember what I said about there being no air on the moon?

KFG

Re:Danger?

[Upsilon Andromedea]

They better get there in a hurry. The dust is falling at 1.6 m/s^2. Ya see, there's no air to keep it wafting about.

Well, GoOoOoOoOoOoOoOoOlly, you're right smart, teach! No air, imagine that!

They did a lot of shit we call by the technical term, "walking." Bit driving too. Not to mention the fact that the moon gets wacked by space rocks at a pretty good rate. Ever see a meteor shower? Remember what I said about there being no air on the moon?

Sorry, can't referece the article more specifically in response to angst.

Re:Danger?

[einhverfr]

Don't breath out eather

Hmmm... Do you mean

"Don't breathe out ether" or
"Don't breathe out either?"

I suppose that if the Lunarians breathed out ether, that might explain the side effects of extreme drowsiness....

Re:Danger?

[Guysmiley777]

The word you're looking for there is 'abrasive'. Abrasive. Not corrosive.

Re:Danger?

[bergeron76]

You can head to the bunker all you want, but it won't help. Asteroid showers are much like rain showers - they start with a few 'drops' and end in an outright shower/hail.

May the Lord Jesus (happy birthday, br0!) keep us good Republicans safe.

Re:Danger?

[Wavicle]

or corrode a bases walls over time

Yes, because of those strongly westerly breezes on the moon that blow the dust around... Come on, unless the base walls move and someone keeps kicking dust at them, they will be just fine.

Re:Danger?

[Fishstick]

Oh, yeah.. duh.

Re:Danger?

[MerlTurkin]

This is correct. They did breath a lot of the stuff and have not suffered any ill effects from it. It got all over everything in the spacecrafts and clothes. We no doubt breath far worse stuff here on Earth. Think about it.

In Other News: Research stolen. Lawsuit Pending

[Anonymous Coward]

"Moondust is electrostatically charged and notoriously clingy." --Dr. Tony Phillips, 2005

"But moondust will cover you. Cover you." --David Bowie, 1996

Commercial opportunity

[mister_llah]

Is it me or does the artist's rendering of the incident look like a bunch of carmel corn is bursting forth from the crust of the earth?

Looks like a 'carmel' variety Pop Secret commercial.

Re:Commercial opportunity

[pnewhook]

What amazes me is the speed that they come up with that artist rendering. They must have these guys sitting around waiting for something to happen so they can draw it.

How do they know the size and speed of the object?

[MichaelSmith]

Obviously they can calculate the objects kinetic energy from the intensity of the flash. This will give them mass or speed, but not both. Perhaps the speed came from their assumption about the origin of the meteoroid, but that could still be wrong, of course.

BTW if anybody is interested in exactly what it was like to be walking on the moon in the 60's and 70's I recommend they have a look at the Apollo Lunar Surface Journal

Danger?!

[Cally]

The main danger of such explosions is the static and toxic moondust, which is thrown around."

The main danger to what, the other moon rocks lying around within 10m of the impact point? Gimme a break, already!

The space.com headline is a bit closer to the mark... "Small space rock spotted hitting the moon".

--
Sometimes I think the only reason I read Slashdot is to complain about it

Re:Danger?!

[Jotii]

It is dangerous to future astronauts and outposts.

Re:Danger?!

[pant]

Not to put too fine a point on it, but isn't that equivalent to worrying about the Sahara desert getting bigger because someone dumped a couple of truckloads worth of sand into it?

Re:Danger?!

[aywwts4]

Mod parent funny! "It is dangerous to future astronauts and outposts."

Does anyone remember the Outer Limits?

[Travoltus]

There was an episode where a near-light speed object was headed toward earth and America and Russia panicked, until Russia saw that it was about to hit the moon instead. Even Russia thanked God for the moon's very existence when the end-of-the-world thingie actually did hit the moon and not Earth.

(Of course, an alien intelligence intentionally fired it at the moon, but still)

It's not a matter of if some highly annoying rocks have been intercepted by the moon... it's more a matter of how many.

I for one am shaking my telescope with joy at my lunar masters. :D

Re:Does anyone remember the Outer Limits?

[Jotii]

Rocks aren't really intercepted by the moon, they hit it because the moon lacks an atmosphere. Earth's atmosphere reduces rocks to harmless strims of heat.

Re:Does anyone remember the Outer Limits?

[XchristX]

Earth's atmosphere reduces rocks to harmless strims of heat.

===
Tell that to the Dinosaurs

Re:Does anyone remember the Outer Limits?

[ScrewMaster]

More to the point, what's a "strim"?

Re:Does anyone remember the Outer Limits?

[OverlordQ]

Sorry to burst your bubble, but the Moon *does* have an atmosphere. Although it is very very tenuous, it none-the-less exists.

Re:Does anyone remember the Outer Limits?

[MerlTurkin]

Wrong but thanks for playing. Most meteor shower meteors are sand grain-pea sized so yes, THEY burn up totally. Random meteoroids that are big enough to have partly survive entry that make it to ground are called meteorites of coarse. Many hit Earth every day. Most end up in the oceans naturally.

Toxic moondust, eh?

[wampus]

1. Who did NASA feed the moondust to to determine it is toxic?
2. If you are inside on the moon, one would presume the dust isn't
3. If you are outside on the moon and this happens, you just had 70kg of TNT dropped on you. Getting exploded is your primary concern, followed by death, with moondust toxicity being an also ran

Re:Toxic moondust, eh?

[Bill Wong]

It's very well known that microscopic particles of dust can be very damaging to the lungs.
See Pneumoconiosis and Silicosis.

Re:Toxic moondust, eh?

[Jotii]

Another NASA article says the dust stuck on the astronauts, and that they noticed weird symptoms inside the spaceship.

The explosion was "equal in energy to about 70 kg", which does not mean it exploded like 70 kg of TNT would have. This explosion was much more concentrated. It is unknown how much and in which shape the dust is blown around, but it is probably quite a big area, which means you don't have to be hit by the meteoroid.

Re:Toxic moondust, eh?

[node 3]

1. Who did NASA feed the moondust to to determine it is toxic?

NASA has analyzed moondust. They would be the ones to know its characteristics.

2. If you are inside on the moon, one would presume the dust isn't

That is an illogical presumption, as things on the outside can (and will) become things on the inside.

Additionally, mooondust can be troublesome on the outside as well.

3. If you are outside on the moon and this happens, you just had 70kg of TNT dropped on you. Getting exploded is your primary concern, followed by death, with moondust toxicity being an also ran

1. The Moon lacks an appreciable atmosphere which makes explosions (among other things) act differently on the Moon compared to on the Earth.
2. If a nuclear bomb explodes, radiation is a concern, even after the time for worrying about "getting exploded" has passed.

Re:Toxic moondust, eh?

[MemoryAid]

Bullets and meteorites can also damage the lungs, if applied appropriately. That doesn't make them toxic. Toxicity implies some chemical interaction that impairs bodily function. Carbon monoxide impairs oxygen uptake, for example. Fine dust particles irritate the lungs by abrading them, causing the body to respond by... Well, I'm not a doctor; I don't know the details, but still....

Re:Toxic moondust, eh?

[einhverfr]

If you are inside on the moon, one would presume the dust isn't

The main problem is that moondust is electrically charged and will stick to all sorts of things. This makes it easy to get in side, though this characteristic should make it simple to design filters...

If you are outside on the moon and this happens, you just had 70kg of TNT dropped on you. Getting exploded is your primary concern, followed by death, with moondust toxicity being an also ran

Ok. On the earth an explosion is largely a concussive sound wave that throws shards of things at people. Both of these are concerns one earth. In space nobody can year you scream so the sound wave isn't a concern. On the other hand, getting hit with extremely fast-moving toxic dust would be (ever operated a sand-blaster?). Basically, if you were on the surface of the moon, I would expect dust exposure not to be abnormal unless you were close enough to the explosion to be damaged by dust particles moving at very high speeds. Also no air resistance means that these things don't decelerate, so although the quantity of particles hitting, say, a square meter might go down with the square (or cube not sure which-- I side with square though) of the distance from the explosion, the velocity won't go down.

In other words, the toxicity of the dust is likely to be a secondary concern to the explosion but the aside from the damage that this could cause, I would suggest that the moondust is so prevailent on the moon that if you had an outpost there you would already have mechanisms to manage the danger.

Maybe

[value_added]

... it had something to do with the cheese?

Re:How do they know the size and speed of the obje

[Anonymous Coward]

Eh, if you know the kinetic energy wouldn't you know the *product* of the mass AND speed, but not either individually?

Been a while since I've taken physics but it seems intuitive...

Foxnews suspects terrorist

[Timo_UK]

Congress extends PAT RIOT act to include the moon.

Re:Foxnews suspects terrorist

[Bob of Dole]

I, for one, think the PAT RIOT act is a great thing for america. Riots made of up people named Pat have taken a horrible toll on our nation, and it's about time someone did something to stop these horrible pat riots.

Re:Foxnews suspects terrorist

[Anonymous Coward]

For the current crisis, the Bush administration advised citizens to seal doors and windows with duct tape.

Re:Foxnews suspects terrorist

[Ian Peon]

"The children are our future! The time is now! We will blow up the moon!"

Apparently We Are Living In The Mirror Universe

[nurhussein]

In the "real" universe, it is Praxis that explodes, and we receive the Klingons for a peace treaty.

I guess now this means we'll have to take the iniative and go meet Chancellor Gorkon.

Re:Apparently We Are Living In The Mirror Universe

[cnerd2025]

Science Officer:: Sir, apparently the explosion eminated from Earth's moon in the Terran solar system.
Capt. SULU: ::especially gay voice:: Omygod! Is that what we felt!? I thought I was maybe dreaming about what we did last ni--
Comm. Officer: We're recieving a communique from the Klingons
SULU: Those guys are so hot. Put him through, hehe!
Klingon: This is a message from the Klingon High Command. We monitored an explosion coming form your Terran solar system. Do you require assistance?
SULU: Hehe. Yes, there was an "incident" near Earth. Please obey the treaty and stay out of the neutral zone, unless you want to be especially naughty...hehehe...I'd never tell ;-)."
Klingon: Well, we're coming anyway. We want to assassinate Captain Kirk becasue he's such a bad actor while pretending to be on a peace envoy. Then somehow McCoy and Spock will end up on an asteroid and Kirk's ghost will come back to have sex with some woman on the penal colony.
SULU: Hehe. I want to go to a penile colony!
Klingon: I can arrange that.
Weapons Officer: Klingon Battleship decloaking off of port bow!
::SULU is beamed off of the bridge.::
Klingon: to SULU The rumor about Klingon prisons is "don't drop the bathing eels!" hahahaha
SULU: This is going to be fun!
=/\=End Transmission=/\=
Comm Officer: We've recieved a transmission from Earth. Apparently Sulu had a massive moon orgy, including Spock, Kirk, and his Klingon Partner. Spock's ears apparently got in the way and began the genesis effect, pissing off the Klingons, killing and rebirthing spock, and making Kirk shout "KHAAAAAAAAN!" I'm really beginning to have my doubts about this universe, Captain.
Sci. Officer, de facto Capt.: aside Why did our ancestors get rid of "Don't ask, don't tell?"

THAT'S NO MOON!

[Anonymous Coward]

Oh wait... nvm.

That's a first...

[Jugalator]

That's the first time I've heard a meteor impact referred to as "explosion on moon spreads moondust".

I'm no astronomer so I'm not sure it's written that way and posted here on Slashdot because it's really something notable just having happened, or it's just a one among thousands of meteor impact caught with a camera?

Re:That's a first...

[space_man51]

While I agree that the title of the article was an exaggeration, there are a few notable points about this event:

1. The telescope recorded the impact on the very first night of observations. This suggests that meteors may hit the moon more often than we think, especially in between meteor showers, when no one is looking.

2. People are actually starting to worry about this. The fact that there is a dedicated telescope set up to watch the moon for meteor impacts suggests someone out there takes this problem seriously (without getting into the argument if it's a real problem or not).

Re:That's a first...

[Deadstick]

An explosion doesn't have to be a chemical or nuclear reaction. When a small object collides with a large one at very high speed, a load of kinetic energy gets converted to heat in a small fraction of a second, melting and vaporizing a quantity of material. The high temperature generates very high pressure, and the hot matter proceeds to escape forcibly in every available direction. That's an explosion, and that's why meteor craters are bigger than the meteors that made them.

The only difference between this and a TNT explosion is the source of the energy.

rj

Re:That's a first...

[John Hasler]

> People are actually starting to worry about this. The fact that
> there is a dedicated telescope set up to watch the moon for meteor
> impacts suggests someone out there takes this problem seriously

"Worry" is not the only reason for watching rocks hit the moon. For example, the ages of structures such as large craters and lava flows are estimated by using crater counts. Observing the frequency of impacts could help calibrate this.

Locale

[dumpsterdiver]

> Explosion on Moon Spreads Moondust But there, they just call it "dust" :p

Re:Locale

[noidentity]

Bah! Around here, we refer to things like Earthdust and Earthdirt, as in "Don't get the place Earthdirty", or "I'm about to Earthdust the house".

This is why you should keep your helmet on

[harlows_monkeys]

For the foreseeable future, any life on the moon will be in a spacesuit that is completely sealed, or inside a building or ship that is completely sealed. So, would toxic moondust be a problem?

I suppose one might have to be careful when opening an airlock, lest moondust enter the airlock and then spread to the inside of the ship, but without an atmosphere, any dust blown up will settle quickly, so a simple rule of not opening an airlock right after anything nearby explodes should be sufficient.

Or is the risk that it will get on the outside of suits, and be hard to clean off, and so will be carried in?

Re:This is why you should keep your helmet on

[sjames]

According to the astronauts who went there, it stuck to their spacesuits and turned the lander's cabin into a dusty grimey mess. So, the risk is tracking moondust into the house. That means that the airlocks will have to provide means of decontamination for returning moon walkers.

Essentially, the electrostatic dust will stick to their suits easily as they disturb it by walking. Once pressurized in the airlock, it will tend to lose it's charge and float freely in the air. Airborne moondust should be about as good for you as free floating asbestos, but the exposure would be 24/7 rather than the 8/5 occupational hazard.

At the least, they will need compressed air/vacuum cleaning and electrostatic filters. Another possability would be a spray on/peel off plastic that doesn't stick to the suit surface but can entrap the dust or a sort of super lint roller.

Re:This is why you should keep your helmet on

[mr_z_beeblebrox]

Or is the risk that it will get on the outside of suits, and be hard to clean off, and so will be carried in?

That, and those rude people from neighboring moon bases who NEVER wipe their feet before they come in.

Re:This is why you should keep your helmet on

[karlrado]

And the astronauts in the Apollo program weren't out walking with any of these "explosions" going on nearby, at least none that we knew about. Any dust they brought in was kicked up while they were out driving the buggy around and doing their experiments. I suspect that the dust from an impact must settle quite quickly with no atmosphere to suspend the particles. So the "bringing the dust into the living quarters" issue would exist independent of the impacts and would need to be addressed if we were to go back to the Moon.

Re:This is why you should keep your helmet on

[a1englishman]

So, would toxic moondust be a problem?

Yeah, it would be a problem if your habitation were hit by a meteor. Or at least, one of your least troublesome problems. The outrushing oxygen may rank higher.

moon dust

[BushCheney08]

It'd be pretty cool if the scattered moondust headed this way and burnt up in the atmosphere. We'd get a nice little moondust light show.

Explosion?

[Efg�]

Well of course. How do you think lunarians dig all these craters? With a shovel?

So thats

[Timesprout]

Where my kite went.

Slight error in late night math

[lw54]

Yes, sorry about that.. slight miscalculation.

Irony

[mister_llah]

Whose "caramel" ...

Oh you mean it's...

*taps the subject*

Uh oh..

[Anonymous Coward]

Looks like santa missed earth ;_;

Its a good job...

[Skiron]

...the Apollo missions were faked, otherwise this could have hit some very expensive equipment up there and damaged it beyond repair!

Re:Its a good job...

[jdbartlett]

You forget: the Apollo missions were faked because the CIA already had a fully operational moonbase.

Several agents are currently Missing In Action, presumed dusty, or just plum squished.

Dammit Man......

[mormop]

So that's where Saddam hid the WMD!!!!!

Re:Dammit Man......

[HermanAB]

Well, actually, that was an alien muslim spacecraft on a suicide mission...

It seems..

[kronocide]

It seems Slashdot is doomed to have a silly relationship to moondust for all time. "Exploding moondust bounces like a toxic canonball."

Re:How do they know the size and speed of the obje

[Captain_Chaos]

BTW if anybody is interested in exactly what it was like to be walking on the moon in the 60's and 70's I recommend they have a look at the Apollo Lunar Surface Journal

and/or go see Magnificent Desolation in your nearest IMAX theater. I've seen it and it's very impressive.

you insensitive clod

[Lighterup]

moonestrials? They object to being slapped with your terran labels. As lunar citizens they prefer to be called Lunies.

Re:Not an explosion ...

[pnewhook]

a rock slamming into another rock does not cause an explosion

Yes it does. The force of the impact is great enough that it vaporizes the ground around it. This molten rock cloud then expands and rapidly cools releasing a huge flash of light as it does so. In short an explosion, albeit one without sound.

Re:How do they know the size and speed of the obje

[Anonymous Coward]

BTW if anybody is interested in exactly what it was like to be walking on the moon in the 60's and 70's I recommend they have a look at the Apollo Lunar Surface Journal

On the other hand, if you interested what it was like during the 80's, I recommend viewing a Micheal Jackson video.

News Flash...

[flynns]

NEWS FLASH!!! Big rock hits another rock full of dust! DUST CLOUD RESULTS!!!! /panic

IMAO did it!

[bobbuck]

The "realistic plan for world peace" has begun.

http://www.imao.us/docs/NukeTheMoon.htm

Pish posh!

[Dystopian Rebel]

I don't believe anything Nasa says since they those faked Moon Walks.

Not the first...

[Deadstick]

...meteor impact observed on the moon, actually. Five English monks saw a much larger one in 1178 as they were finishing up a day's work on their monastery's farm. There's a crater named for Giordano Bruno that may be the result of that.

rj

Re:Not the first...

[Quiet_Desperation]

Actually, that story has been debunked by a few people, although I don't have a cite or a link handy, sorry.

Re:How do they know the size and speed of the obje

[sjames]

Obviously they can calculate the objects kinetic energy from the intensity of the flash.

There are several ways they can go, but some supposition is needed.

They can estimate the product of speed and mass from the flash. IF they can examine the crater depth they can get some idea of the two factors. Large slow (reletively speaking) impacts might for example produce large shallow craters while small very fast objects produce deeper smaller craters.

Without examining the crater, they have the intensity and spectral qualities of the flash to go on. A larger slower object would be redder and more spread out.

Eh...

[Quiet_Desperation]

When they said they were planning a sequel to Shoemaker-Levy 9, I was expecting a bit more. Damn budget cuts!

In similar news ...

[redzebra]

Explosion on earth spreads earthdust
Explosion on mars spreads marsdust

I must be new here to still expect title's which actually tell what the article is about ? Something simple like : Explosion on the moon spotted ? stll seems hard.

Then the summary is 2 lines : The first being informative. The second completely out of context. I wished editors just added a list of moon related articles in this case iso trying to make up nonsens. The only danger here is that the moon doesn't have an atmospher to protect you from direct astroid impact. The fact that inhaling moondust is the least of you problems if you're in its trajectory.

Re:How do they know the size and speed of the obje

[Somegeek]

They believe that the object was a Taurid. A quick Google shows their speed about 65000 mph, which translates to 29 kps. I bet the 2 kps difference comes from the moon's relative speed at the impact.

Re:Whooo....No Virginia....

[mr_z_beeblebrox]

What is this? News for stupid assholes who easily believe that the air on the moon should be cleaned with US taxmoney?

There's no air to clean.

Re:How do they know the size and speed of the obje

[Inspector Lopez]

There is other information available.

For example, the date of the observation (7 November), and commentary in the article leads to the reasonable supposition that the observation was from a meteor in the Taurid stream http://comets.amsmeteors.org/meteors/showers/tauri ds.html. Since the Taurids are very well characterized, their orbital velocity is extremely well known, and thus the net impact velocity would be known with great precision, too. If it's one of the Taurids. Which is not so bad an assumption.

Even without the Taurid assumption, you can look at other data to put some bounds on the meteor velocities. For example, there are excellent "head echo" observations by some big radars:

Arecibo http://www.copernicus.org/EGU/acp/acp/4/947/acp-4- 947.pdf

Jicamarca http://www.copernicus.org/EGU/acp/acpd/3/6063/acpd -3-6063.pdf

and there have been several PhD dissertations in recent years exploring a variety of aspects of meteors, just from the plasma physics side (let alone the "meteor astronomy" side); check out Close and Dyrud from 2004 at BU, http://www.bu.edu/astronomy/alumni/phd.html.

The past decade has been a remarkably active time for meteor studies. There will be presentations about meteors at the URSI meeting in Boulder CO 4-7 Jan 2006, http://cires.colorado.edu/ursi/

Flamebait?

[Skiron]

Maybe my joke is too complicated to understand for the modders...

You left out "Imbrium".

[Colin Douglas Howell]

The description of the impact site should read "the edge of Mare Imbrium (the Sea of Rains)".

I thought this was covered

[beforewisdom]

Geeze after all of that nuclear waste exploding and the near destruction of moon base Alpha the government is still screwing around on the moon.

Stupid headline

[back_pages]

Explosion on Moon Spreads Cotton Candy!

Not THAT's a news story.

Boring

[deblau]

So every time the Mooninites launch an attack on the Golgotron, it makes Slashdot? Nothing to see here, move along...

Why is this an "explosion"?

[gearmonger]

Was there actually some sort of combustion in this impact? I thought the moon's atmosphere was inadequately oxygenated to support an "explosion".

Journal entry:

[Anonymous Coward]

July 21, 1969

TRANQUITY BASE: This is Tranquility Base. The Eagle has landed.
Jesus H. Christ, Houston, we're on the fucking moon. Over.

HOUSTON: Roger. Tranquility we copy you. We cannot believe you
are on the fucking moon. Repeat. Cannot fucking believe it. Over.

TRANQUILITY: It was a smooth touchdown. The moon for Christ's
sake, the moon. Over.

HOUSTON: Roger that. You're clear for TI, walking on the moon. Over.

TRANQUILITY: We copy. Walking on the moon. Jesus. Over.

HOUSTON: We read you. Over.

TRANQUILITY: I'm on the bottom rung of the ladder. Just one more
step and I'm... (long pause).

HOUSTON: Tranquility?

TRANQUILITY: Holy (pause) living (long pause) Fuck!

HOUSTON: Tranquility? Do you copy?

TRANQUILITY: Are you fucking believing this? Over.

HOUSTON: We read you. Over.

TRANQUILITY: I abso-fucking-lutely am standing on the surface
of the fucking moon. I am talking to you from the goddammed
fucking moon. Jesus H. Christ in a chicken basket.

HOUSTON: Holy Shit.

TRANQUILITY: Holy mother of fuck. The fucking moon. Over.

HOUSTON: A-fucking-affirmative. Over.

Explosion on Moon! Moon blown out of orbit!

[lma]

I can't be the only Slashdot person who's first thought was that a nuclear waste dump on the moon was beginning to go critical, and that this explosion was the precursor to a larger one that would blow the moon out of orbit? Wasn't that supposed to happen September 13, 1999?

Larry

Re:A scary occurence

[trygstad]

Jesus saved him and he became a Muslim. Go figure. Religion aside, personally I suspect a minor psychotic incident, but I am not a mental health professional--nor do I play one on TV--so my opinion is pretty meaningless.

Re:Dangeri

[earthstar]

The main danger of such explosions is the static and toxic moondust, which is thrown around.
Danger to whom exactly? Should I be hitting the bunker to dodge that toxic moondust?

Danger to Neil Armstrong!

Was it a meteoroid or

[clockmaker]

a monolith?

Re:Was it a meteoroid or

[Steven_Lunn]

Simple. Its the aliens testing their latest weapons prior to the Earth invasion.

Find the Maretha Sea of Rains

[merc]

Using google

Same old, same old...

[HiyaPower]

the chronicle of gervaise

18 June 1178 (Julian calendar)

In this year, on the Sunday before the feast of St. John the Baptist, after sunset when the moon has first become visible, a marvellous phenomenon was witnessed by some five or more men who were sitting there facing the moon. Now there was a bright new moon, and as usual in that phase, its horns were tilted towards the east and suddenly the upper horn split in two. From the midpoint of this division a flaming torch sprang up, spewing out, over a considerable distance, fire, hot coals and sparks. Meanwhile the body of the moon, which was below, writhed, as it were, in anxiety, and, to put it in the words of those who reported it to me and saw it with their own eyes, the moon throbbed like a wounded snake... Then after these transformations the moon from horn to horn, that is along its whole length, took on a blackish appearance.

One (controversial) interpretation of this narrative, first suggested by Dr Jack B Hartung some 800 years later, is that it is a description of a crater impact in progress. The "upper horn split in two" is the apparent effect of a plume of dark dust or vapour, the "flaming torch [of] hot coals and sparks" describes the molten ejecta, and the way in which the rest of the Moon "writhed", "throbbed" and eventually "took on a blackish appearance" could be the effects of a temporary lunar atmosphere of gas and vapour created by the impact.

Re:How do they know the size and speed of the obje

[robogun]

He asked the size and speed. All that can be inferred is the energy of the strike. The mass can be derived from that along a range of impact speeds, but the diameter is nothing but pure guesswork.

For instance, if the meteoroid was iron, it could deliver the same impact in a smaller package. If it was primarily carbonaceous chondrite, it would have to be much larger.

Note in the summary only the diameter is given (stated as fact), not the mass or speed of the object. The summary was weak from a scientific standpoint. You would think the danger of moondust is that it kills on contact or something.

Comment removed

[account_deleted]

Comment removed based on user account deletion

Re:How do they know the size and speed of the obje

[idsfa]

Actually, there are several relationships between various physical properties of the projectile, the target and the ejecta.

• the ratio of the densities of the projectile and the target and the distribution of ejecta allow you to determine the velocity (times the sine of the impact angle).
• the ratio of densities is related to the diameter to the crater diameter
• (others I don't remember right now ... physics was a while ago)

That said, typically the impact velocity is assumed from the orbital velocity and the location of the strike ...

WMD?

[jpellino]

Get Rumsfeld on this, stat!

DO NOT PANIC !!!!!!

[freaker_TuC]

Use duct tape to close all holes and the magical moondust will not get you ... tonight

Apocalyptic Event Observed On The Moon

[Mr. Viddy]

The original story seems to exist merely for entertainment purposes as the chances of any danger befalling us here on Earth is almost non-existent. It is a clever bit of marketing on the part of the lab that put out this information but it falls under a "chicken little" event.

Re:How do they know the size and speed of the obje

[MichaelSmith]

Magnificent Desolation

Yes, I thought the landing from the POV inside the LM was good, and the "what if" bit with the rover crash was good as well.

Re:Whooo....No Virginia....

[arkane1234]

==quote==
What is this? News for stupid assholes who easily believe that the air on the moon should be cleaned with US taxmoney?
== end quote ==
There's no air to clean.

And thus the joke's punchline...

Re:How do they know the size and speed of the obje

[MichaelSmith]

You would think the danger of moondust is that it kills on contact or something.

Dust accumulation was thought to be a major life limiting factor for the Mars Exploration Rovers, but it turns out that dust devils blow dust off the solar panels and keep them relatively clean.

One of the two early soviet lunar rovers died when it got caught in some rough terrain and collected some dust on a radiator. It was killed by heat accumulation shortly after.

The apollo lunar roving vehicles (and their occupants) collected a lot of dust because it was kicked up by the wheels. If they had vulnerable parts which need to radiate heat they would have needed maintenance to keep working.

The apollo 12 crew found the surveyer 3 probe covered with dust because they flew over it too low during final approach to their landing site.

So dust is a problem on the moon (less so on mars) but mainly because of the movement of vehicles kicking the stuff up.

Re:How do they know the size and speed of the obje

[einhverfr]

Acutally half the product of the mass and the *square* of the speed is the kenetic energy. In this case, kenetic energy K = (mv^2)/2.

Not that this is practically that different from the view point of calcualting the mass or the speed.

Re:I don't believe in the moon

[Quiet_Desperation]

You know, you mods need to take some Prozac or something. Zoloft. Anything.

Re:Not an explosion ...

[MerlTurkin]

Yes it does grasshopper....