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Cometary Fireworks Go Off Without Hitch
Posted by
Zonk
on Mon Jul 04, 2005 07:01 AM
from the waaay-better-than-the-movie dept.
from the waaay-better-than-the-movie dept.
PingXao writes "The JPL Deep Impact mission has successfully slammed a sattelite into Tempel 1 at 23,000 mph. (37,000 kph). The autonomous navigation system was primed for up to 3 course corrections in the final 2 hours of flight but only had to execute two of them. The second was so small - expending less than a pound of propellant - that impact would have occurred without it. Initially thought to be shaped like a pickle, it came to resemble more of a banana shape as comet Tempel I drew closer. Impact was estimated to have released 19 Gigajoules of energy, or the equivalent of 4.5 tons of TNT."
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Comet Probes Given New Duties 48 comments
iamlucky13 writes "In January of 2004, the NASA's Stardust mission made a flyby of comet Wild-2, taking images and collecting samples from its tail that have since been returned to earth in a detachable capsule. On July 4, 2005, Deep Impact smashed a 350 kg projectile traveling 37,000 km/h into comet Tempel 1 as part of its studies of that object. With both craft in good shape at the end of their missions, NASA has been considering additional tasks for the probes. These plans have now been confirmed with a variety of tasks costing an estimated 15% what a new mission would. Among the new duties will be a revisit of Tempel 1, a flyby of comet Boethin, and transit studies of known extra-solar planets."
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Where are the Stars in the pictures? (Score:4, Funny)
Re:Where are the Stars in the pictures? (Score:3, Insightful)
Re:Where are the Stars in the pictures? (Score:4, Informative)
Pedantic answer: orbit == complete circuit. It didn't do even half an orbit http://deepimpact.jpl.nasa.gov/mission/factsheet-t ext.html [nasa.gov]
To say it was orbiting around the sun when it didn't even go half-way would be like me saying I walked around the block when I just went to the corner, or that Alan Shepards sub-orbital flight was an "orbit". What it did was sub-orbital.
Definition http://www.answers.com/orbit&r=67 [answers.com]
Now, it might be nit-picking, but it didn't "revolve around" any body - its "orbit" was really just an arc that started and completed in under 1 revolution. If it had taken 1 or more revolutions to complete the mission, then you could have said it had, in fact, orbited the sun. Pedantic, but wtf, this is slashdot, and this is the sort of "angels on a pinhead" argument that gets people to biteParent
And the real question is ... (Score:5, Funny)
Seems like NASA has missed the chance to answer this profound question raised by Sci-Fi enthusiast by not putting a microphone onboard the flyby probe.
Re:And the real question is ... (Score:4, Informative)
Nope, you need a medium to transmit vibrations. Whales do just fine with a fluid, in fact a fluid is better, because it's denser. More molecules in closer contact. They "talk" to each other across hundreds of miles using low frequencies. That would be the whales. Molecules don't talk. They don't even "talk." Don't anthropomorphize molecules. They hate that.
Solids work great too. A microphone on the probe would have recorded a sound.
A microphone next to the probe would not, because because an insufficiently dense medium, like a gas, to carry the vibration.
KFG
Parent
Re:i'm being picky, but... (Score:4, Informative)
Definition [answers.com]:
fluid
n.
A continuous, amorphous substance whose molecules move freely past one another and that has the tendency to assume the shape of its container; a liquid or gas.
Parent
A mini-animation (Score:4, Informative)
Re:A mini-animation (Score:5, Informative)
I think it contains what are by far the best, and closest pictures of a comet nucleus - and I've no idea if it's from 'final' data yet. I gather there's a lot left to download from the flyby probe, but was it a Huygens-Cassini style relay setup or was impactor data received directly on Earth? If it's the latter, I suppose there isn't much chance of retrieving any more of the close-up data, as the delicate hardware stuck to the impactor's copper mass must have made quite a splat...
Parent
Re:A mini-animation (Score:3, Insightful)
Re:A mini-animation (Score:3, Insightful)
Re:A mini-animation (Score:3, Funny)
I think we have a potential solution to all those orbital corrections on the ISS. We simply need to find one of those "fixed points in space" and anchor the station to one, thus keeping it forever still. Additionally, we'll be able to figure out which way the earth/sun/galaxy/universe/etc is moving once and for all once we see which way the station flies off after being anchored...
(Yes, I'm guessing (and hoping) that you were being sarcastic about that one. I just couldn't resist
PWND!!11 (Score:5, Funny)
Seems a Lot Smoother Than I Would Have Thought (Score:4, Insightful)
Ugliest Dog I Ever Saw [whattofix.com]
Re: Seems a Lot Smoother Than I Would Have Thought (Score:3, Interesting)
> With all that outgassing, you would think a comet's surface would be a lot more sharp -- full of crevasses and ridges (like it was on Deep Impact) But this one seemed almost smooth, like an asteroid.
Some of the final picture before impact showed what looked like big chunks, perhaps glued together by snow.
I wonder whether the outgassing weakens it enough to "melt" to a new configuration each time it passes the sun.
Result (Score:5, Interesting)
"It was like mosquito hitting a 747. What we've found is that the mosquito didn't splat on the surface, it's actually gone through the windscreen."
The photos too, are quite amazing. A huge amount of stellar dust, ice, and rock exploded out of Tempel 1's surface. All from the impact of a probe just the size of a washing machine.
Over the following few days, the second module of the mission will further analyse the materials ejected from the comet, and it is believed scientists will discover much about the creation of the universe (some of the material hasn't been disturbed in over 4 billion years) and the composition of comets in general over the next few months as they complete their analysis of this great event.
Re: Result (Score:5, Insightful)
> This is quite likely the finest result Nasa has had for a long time.
Ignoring a couple of rovers on Mars...
Parent
Re: Result (Score:4, Insightful)
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Re:Result (Score:3)
Don't forget the gigantic success of the Cassini-Huygens mission from January which was a huge success, partly for NASA and the Mars Exploratioon Rovers which are still strolling around Mars!
Last Words (Score:5, Funny)
I wonder if it will be friends with me?
OR... (Score:4, Funny)
Or the equivalent of a Supersized meal from McDonalds...
impact seen from Lowell Observatory (Score:4, Interesting)
There was supposed to be a Kaboom! (Score:4, Funny)
Oh Well. Guess next time I will have to use an Illudium-Q-36 Space Modulator.
(toddles off)
What's all the fuss about. (Score:5, Funny)
NASA have proven quite adept at smashing space craft into various celestial bodies.
Oh hang on...maybe they weren't suppose to do that!
Astrologist Sues NASA over comet crash (Score:5, Funny)
http://www.abc.net.au/news/newsitems/200507/s1406
http://edition.cnn.com/2005/TECH/space/07/04/deep
Re:Astrologist Sues NASA over comet crash (Score:5, Funny)
Anyway, if she is good at her job, surely she should have seen this coming? Even I knew it was going to happen, and my crystal ball hasn't worked right for years.
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Ob Monty Python quote (Score:3, Funny)
Sir Bedevere: ...and that, my liege, is how we know the Earth to be banana shaped.
King Arthur: This new learning amazes me, Sir Bedevere. Explain again how sheep's bladders may be employed to prevent earthquakes.
(Okay! I know it is not about the Earth, but anyway...)
Size (Score:5, Funny)
Maybe the Unix "units" program will do it for me.
Let's see:
$ units
1989 units, 71 prefixes, 32 nonlinear units
You have: washingmachine
You want: volkswagen
* 0.25
/ 4
You have: washingmachine
You want: librariesofcongress
* 0.0001
/ 10000
Ah, now I can visual it.
9/11 for comet people (Score:4, Funny)
Experiment result (Score:5, Funny)
Tempel: 1
Impactor: 0
Partly Offtopic (Score:5, Funny)
http://edition.cnn.com/ [cnn.com] International headline: 'NASA probe collides with comet'
So CNN has an official policy of only providing cheesy headlines to Americans? That's a policy I can live with though.
Re:Partly Offtopic (Score:5, Funny)
"After intense negotiations, the comet has been deemed a threat to national security. The freedom-hating comet bowed down to the vastly superior US forces. The White House says that this is a direct response to 9/11."
Parent
I won't be impressed.... (Score:4, Funny)
So how about those Electric Universe people? (Score:5, Interesting)
Seems the electrical universe people haven't had time to update their website [thunderbolts.info] about their prediction about the results [slashdot.org]. IIRC, they were saying that the results would be much less spectacular than predicted, and yet a few hours ago I heard some of the NASA people expressing surprise because the impact released a lot more material than most of them expected. The electric universe proponents also seemed to think that the impactor electrical systems would fail before it reached the comet (because of "megalightning" and all that), while they seem to have have lasted right up until the impact.
So....will they do the right thing and modify their theory to fit the observations, or will we be treated to a lot of hand-wringing about how the theory actually predicted this result (but us non-electrodynamical people just don't understand the theory and its implications)?
And will /. post a follow-up article about the electric universe proponents' reaction to the results, or is that not news for nerds?
What a bunch of loons. (Score:4, Funny)
What's the name of that condition? They can accurately calculate the energy released when they open a bottle of soda, but when they can't find a belonging of theirs, the notion that a space alien came by and collected it for testing seems just as plausible to them as the possibility that they just misplaced it. No grasp on reality.
Parent
And, of course, In Russia the comet hits _you_ (Score:5, Informative)
Next Time (Score:4, Insightful)
Next time would be better if:
Re:4.5Kt, surely? (Score:5, Informative)
19/4.184 ~ 4.5 tonnes TNT
TNT has a lot of energy
Parent
Re:4.5Kt, surely? (Score:3, Interesting)
Yes, it's just that the news last night said "about 5 kilotonnes", so does that mean that the 4GJ figure is wrong or was the news...Actually why don't we just calculate it:
.5*372Kg*(37000Km/hr=10000m/s)^2 -> 18.6GJ.
So, the news was wrong. Fair enough.
TWW
And now in terms you're familiar with (Score:5, Funny)
1 Snickers contains 280 Kcal = 1172080 J = 0.00117208 GJ
19 / 0.00117208 ~ 16210.5 Snickers
So the amount of energy released is the equivalent of about 16.2 Megasnickers.
Parent
Re:And now in terms you're familiar with (Score:4, Informative)
Hmmm
Megasnickers-level detonations are still a few years away with current technology.
Parent
Re:4.5Kt, surely? (Score:5, Informative)
I wouldn't be surprised if a lot of the apparent 'explosion' visible in the images is due to sunlight illuminating the plume of dust produced by the impact. Comet nuclei are pretty dark, so I suppose the exposure times were probably cranked right up to see anything of the nucleus itself.
This is all guesswork, of course, but I remember a similar explanation of the 'explosions' visible when the Shoemaker Levy 9 comet fragments hit Jupiter [nasa.gov]. Mankind has kind of built our own tiny version of that!
Of course, the above could all be utterly incorrect...
Parent
Re:19 Gigajoules of energy (Score:5, Interesting)
There's a handy tool for doing that kind of calculations, called 'units'.
A marsbar (65g) has about 294 kilocalories (source: http://www.weightlossresources.co.uk/calories/calo rie_counter/chocolate_sweets.htm [weightloss...rces.co.uk])
So, we edit /usr/share/misc/units.dat (may wary depending on distro) to add the line:
marsbar 294 kilocalorieWe then launch units:
%units2085 units, 71 prefixes, 32 nonlinear units
You have: 19 gigajoules
You want: marsbars
* 15435.619
/ 6.4785221e-05
You have:
So apparently, 19 gigajoules of energy equals ~15436 mars bars.
Parent
Re:Let's hope that... (Score:4, Funny)
Parent
Re: Insides on the outside (Score:4, Interesting)
> If the internal makeup of this comet does represent the compounds present at the start of the solar system, there could be some serious head scratching and changing of theories going on if amino acids are found, let alone any more complex organic compounds like RNA/DNA, however unlikely.
We already know that amino acids are present in deep space. Slightly more complex molecules too, IIRC.
Of course, that just means they're relatively easy to form by non-biological processes, so it doesn't necessarily follow that they originated on earth by falling from space.
Parent
Re:Insides on the outside (Score:3, Informative)
It's not the explosion that detects the presence of organic compounds but the observations you can make about the generated blast debris. Either mid or infra-red spectroscopy or radio emissions reveal what compounds are present by their signatures.
Think CSI in space :-)
Re:No satellites involved (Score:3, Interesting)
The sibling post of this one, which says the object needs to be in orbit in order to be a satellite, gives the correct definition of a satellite.
A block of copper can thus be a satellite, but the impactor was clearly not orbiting the comet.
You see?
Re:No satellites involved (Score:4, Funny)
Parent
Re:Next! (Score:5, Interesting)
You mean the Rosetta [esa.int] mission?
Currently en route to a close rendezvous with comet Churyumov-Gerasimenko, to be followed by releasing a lander (which will use a harpoon to cling to the surface). It was in a position to make distant observations of comet Tempel for the current fireworks show.
It won't do what you describe but will instead take a roundabout route that will allow it to basically sneak up on the comet.
Oh, and it's European, not American :-)
Parent
Re:a question of priorities in the united states. (Score:3, Insightful)
The cost of this mission to you does not represent tax dollars to you. In fact, it's probably tax "cents". Tell me how a few million dollars will end starvation, genocide or ecological collapse? It would just be wasted there, too. At least this way we "waste" it in new and unusual ways and gain knowledge, but I know this is not important to you.
Re:JPL Media types, please read this (Score:5, Informative)
Second, automated image enhancement is pointless. As an amateur photographer, I know that each picture needs to be optimized manually, and using automatic settings often works, but not always. You'll get good pictures, but not 12 hours after impact. Plus I'm sure much of what they received wasn't good anyway and had to be thrown out.
Third, you obviously don't know the complexity of these projects. Most of the public doesn't really care about the low resolution pictures - they'll see the high res pictures when they're broadcast by the media. Which means that there's no point for NASA to deal with the 0.1% of the public who think they deserve to get access to those pictures.
Fourth, I'm really rather insulted by your pompous attitude regarding the people at NASA. No, I don't work at NASA. Nor can I call myself a scientist yet. But I'm an undergraduate physics major and so far my plans are to go on to grad school. Right now I'm spending the summer at the biggest NSF-funded project (not hard to figure out which one it is) and I will tell you that the people who run the project are brilliant and have no time to deal with whiners like you. If you really wanted to work on these kinds of missions, why didn't you dedicate your life to science instead of just whining about how you don't have access to all the data. Because I doubt you can figure out much from the data, and I find your arrogance to be purely insulting.
Parent